Anatomy Handbook

ANATOMY HANDBOOK

A Quick Reference for Gross Anatomy

S. Christopher Bennett, Ph.D.

Version 3.1 – August 30, 2003 ii TABLE OF CONTENTS

Introduction ...... 1 Terms of Orientation ...... 2 Terms of Movement ...... 2 Basic Principles ...... 3

HEAD AND NECK

Osteology of the Head ...... 5 Joints of the Skull ...... 6 Muscles of the Posterior Triangle ...... 9 Prevertebral Muscles ...... 11 Infrahyoid Muscles ...... 13 Suprahyoid Muscles ...... 15 Facial Muscles ...... 17 Muscles of Mastication ...... 19 Muscles of the Tongue ...... 21 Extrinsic Muscles of the Eye ...... 23 Cranial Nerves ...... 24 Functions of Cranial Nerves ...... 25 Spinal Nerves of the Head and Neck ...... 27 Arteries of the Head and Neck ...... 29 Arteries and Veins of the Brain ...... 31 Veins of the Head and Neck ...... 33 Cross-section of the Neck ...... 34

BACK

Osteology of the Postcranial Axial Skeleton ...... 35 Joints of the Postcranial Axial Skeleton ...... 36 Intermediate Muscles of the Back ...... 39 Erector Spinae Muscles ...... 41 Transversospinalis Muscles ...... 43 Muscles of the Suboccipital Region ...... 45

THORAX AND ABDOMEN

Muscles of the Thoracic Wall ...... 47 Muscles of the Abdominal Wall ...... 49 Muscles of the Pelvis ...... 51 Muscles of the Perineum ...... 53 Nerves of the Thorax ...... 55 Nerves of the Abdomen ...... 57 Arteries of the Thorax and Abdomen ...... 59 Unpaired Visceral Branches of the Abdominal Aorta ...... 61 Veins of the Thorax and Abdomen ...... 63

UPPER EXTREMITY

Osteology of the Pectoral Girdle and Upper Extremity ...... 64 Joints of the Upper Extremity ...... 65 Muscles attaching Upper Extremity to Trunk - Anterior Side ...... 67 Muscles attaching Upper Extremity to Trunk - Posterior Side ...... 69

i Muscles of the Shoulder Joint - Scapular Muscles ...... 71 Muscles of the Arm ...... 73 Superficial Extensors of the Forearm ...... 75 Deep Extensors of the Forearm ...... 77 Superficial Flexors of the Forearm ...... 79 Deep Flexors of the Forearm ...... 81 Other Muscles of the Forearm ...... 83 Thenar and Hypothenar Muscles ...... 85 Other Muscles of the Hand ...... 87 Brachial Plexus ...... 89 Nerves of the Upper Extremity ...... 91 Arteries of the Upper Extremity ...... 93 Cutaneous Veins of the Upper Extremity ...... 95 Cross-section of the Arm ...... 96 Cross-section of the Forearm ...... 97

LOWER EXTREMITY

Osteology of the Pelvic Girdle and Lower Extremity ...... 98 Joints of the Lower Extremity ...... 99 Muscles of the Anterior Thigh ...... 101 Muscles of the Medial Thigh ...... 102 Muscles of the Posterior Thigh ...... 103 Lateral Rotators of the Femur ...... 107 Gluteal Muscles ...... 109 Muscles of the Anterior Crural Compartment - Dorsiflexors ...... 111 Muscles of the Posterior Crural Compartment - Superficial Plantarflexors . 113 Muscles of the Posterior Crural Compartment - Deep Plantarflexors ...... 115 Muscles of the Lateral Crural Compartment ...... 117 Muscles of the Dorsum of the Foot ...... 119 Muscles of the Sole of the Foot - Layers 1-4 ...... 121 Nerves of the Lower Extremity ...... 125 Nerves and Arteries of the Gluteal Region ...... 127 Arteries of the Lower Extremity ...... 129 Cutaneous Veins of the Lower Extremity ...... 130 Cross-section of the Thigh ...... 131 Cross-section of the Leg ...... 132

ii INTRODUCTION

This handbook contains much of the basic information about the bones, muscles, nerves, arteries, and veins of the body that is needed in a typical gross anatomy course. Such a course typically follows a regional approach, and so does the handbook. Within regions I have divided the material into small packets of information (a group of muscles; the pattern of arteries; etc.). I organize information visually, and so most packets consist of a drawing and some accompanying textual material, usually arranged on facing pages.

I am often asked how one should study anatomy. I do not know how one should do it, I only know how I would study it. First I would divide up the material. In any particular region of the body the muscles can be divided into a number of groups, each containing a small number of muscles. Again I organize information visually so I usually have a drawing or an outline. I have already divided up the material for you. Then to study a group of muscles I would sketch them and label or note the origins, insertions, actions, and innervations. To study the pattern of arteries or nerves I would draw the pattern, name them, note the branching pattern, and where they go or what they do. All the drawings, in this handbook are simple enough that you can draw them. At first I might simply be copying my notes, but soon I would try to put the things down on paper from memory. If I could not remember some things, I would check my notes or look them up in the book, and try again until I had memorized the material and could put it down on a blank sheet of paper. If I can put it down on a blank piece of paper, I know I know it, and I know I can put it down on the test from memory.

After having learned the muscles and the patterns of nerves and vessels, one other thing that I find helpful is to look over illustrations in anatomy texts and atlases and make sure you can understand them.

1 TERMS OF ORIENTATION

┌ Anterior - Toward the front, ventral. ┼ └ Posterior - Toward the back, dorsal.

┌ Dorsal - Pertaining to the back, therefore posterior. ┼ └ Ventral - Pertaining to the belly, therefore anterior.

┌ Superior - Higher than, situated above something else. ┼ └ Inferior - Lower than, situated below something else.

Median - In the middle, referring to the midline of the body.

┌ Medial - Nearer to the midline of the body. ┼ └ Lateral - Farther to the side from midline of the body.

┌ Proximal - Nearest to the center of the body. ┼ └ Distal - Farthest from the center of the body.

┌ Superficial - At the surface. ┼ └ Deep - Below the surface.

TERMS OF MOVEMENT

┌ Extension - Movement that straightens a joint. ┼ └ Flexion - Movement that bends a joint.

┌ ABduction - Movement of a limb or the head away from the midline of the │ body, or in the case of digits away from the axis of the limb. ┼ └ Adduction - Movement of a limb or the head toward the midline of the body, or in the case of digits toward the axis of the limb.

┌ Protraction - Movement (often sliding) of a body part forward. ┼ └ Retraction - Movement (often sliding) that pulls a body part backward.

┌ Elevation - Movement that lifts a body part up. ┼ └ Depression - Movement that pushes a body part down.

Rotation - Movement of a limb about its axis. Medial and lateral rotation move the front of the limb medially and laterally, respectively.

Circumduction - Movement that combines two other movements to move a body part in circles. For example, swinging the upper extremity in a circle combines flexion, extension, adduction, and aBduction.

Note: To avoid confusion it is advisable to say "ad-duct" and "a-bee-duct".

2 BASIC PRINCIPLES

OSTEOLOGY - Osteological features include:

Head - articular end of bone Condyle - rounded knob for articulation Process - bony prominence Tubercle - a small rounded process Tuberosity - a large rounded process Trochanter - another name for a tuberosity on femur Epicondyle - process above condyle for attachment of muscles and/or ligaments Crest - a ridge Foramen - a hole through a bone Fossa - a depression Sulcus - a groove for a nerve, blood vessel, or tendon

MUSCLES

Muscles can only pull!

Tense - apply force without length change Contract - shorten in length to move body parts

Muscles are usually named by conventions:

Action - e.g., Adductor longus Form - Size - e.g., Adductor magnus Length - e.g., Adductor longus Shape - e.g., Deltoideus Location - e.g., Tibialis posterior Attachment - e.g., Pectineus

Muscles have:

1 - Origin - The attachment of a muscle on the bone that is fixed, generally the proximal end of the muscle.

2 - Insertion - The attachment of a muscle on the bone that is moved, generally the distal end of the muscle.

3 - Action - What happens when the muscle contracts. The action is usually described with a term of movement (e.g., flexion, extension, etc.) and the name of either the joint or the body part moved. Thus flex hip and flex thigh are equivalent.

4 - Innervation - Which nerve controls the muscle.

3 ARTERIES AND VEINS

Arteries carry blood from the heart out to the body and veins return blood to the heart. The pattern of arteries and veins is described in the direction that blood flows. Large arteries branch into smaller arteries. Small veins join to become, or empty into, larger veins. Both are subject to topographic name changes, in which the name of a vessel changes after it has passed an anatomical landmark. Thus the External Iliac Artery becomes the Femoral Artery after passing under the Inguinal Ligament. Arteries and veins generally run together and have the same names. Therefore, if one learns the pattern of arteries one knows most veins as well. However, cutaneous veins do not accompany arteries.

NERVES

Nerves carry impulses from and to the brain. Nerves can be sensory, carrying impulses from receptors to the brain; motor, carrying impulses from the brain to muscles; or mixed, both sensory and motor. Nerves generally branch into smaller nerves, but small nerves can join to form a larger nerve. Nerves often run with arteries and veins, but the branching pattern of nerves usually differs from that of arteries and veins, and so the names of nerves usually differ from those of arteries and veins.

VARIATIONS

Variations on the pattern of structures presented in this handbook and most anatomy texts are common. Veins are particularly prone to variation, but nerves, arteries, and muscles also are variable. This will not be a problem in the lecture course because we will learn the "normal" pattern, but those in cadaver labs should be aware that variations occur and not be concerned by them.

ABBREVIATIONS

Terms of Orientation: Anterior Ant. Posterior Post. Superior Sup. Inferior Inf. Medial Med. Lateral Lat. Superficial Superf. External Ext. Internal Int.

SINGULAR PLURAL ———————————————————————— Structures: Muscle M. Mm. Artery A. Aa. Vein V. Vv. Nerve N. Nn. Ligament Lig. Ligg.

4 OSTEOLOGY OF THE HEAD

SKULL - consists of two distinct parts: Braincase and Face

BRAINCASE - Bones: Frontal Parietals (2) Temporals (2) Occipital Sphenoid

Sutures: Sagittal - between parietals Coronal - between frontal and parietals Lambdoidal - between parietals and occipital

FACE - Bones: Zygomatics (2) Nasals (2) Lacrimals (2) Maxillae (2) Palatines (2) Sphenoid Ethmoid Vomer

FEATURES OF THE SKULL

Orbits - sockets for eyeballs Optic Canal - for Optic N. and Ophthalmic A. Superior orbital fissure - between wings of sphenoid for CN III, IV, VI and ophthalmic division of Trigeminal N. Nasal aperature - external opening of nasal passages Nasal septum - separates nasal passages Infraorbital foramen - for Infraorbital NAV to supply nasal region Zygomatic arch External auditory meatus - opening of auditory canal

Greater and lesser wings of sphenoid Sella turcica [=Turkish saddle] - depression for pituitary gland Cribriform plate of ethmoid - for Olfactory N.

Hard palate - formed of palatine and maxillae Pterygoid plates - origin of pterygoid Mm., wall of pharynx Mandibular fossa - articulates with condyloid process of mandible Styloid process of temporal - origin of Stylohyoid, Styloglossus, and Stylopharyngeus Mastoid process of temporal - origin of Digastric, insertion of Sternocleidomastoid and Splenius capitus Occipital condyles - articulate with atlas

Foramen ovale - for CN V2 Foramen rotundum - for CN V3 Foramen spinosum - for Middle meningeal A. Foramen lacerum - closed by cartilage Carotid canal - for Internal carotid A. Jugular foramen - for Internal jugular V. and CN IX-XI Stylomastoid foramen - for CN VII Foramen magnum - for spinal cord

5 MANDIBLE

Body Ramus Angle - insertion of Masseter and Medial pterygoid Condyloid process - articulates with skull Coronoid process - insertion of Temporalis Mandibular foramen - for Inferior alveolar A+N Mental foramen - for Mental A+N to supply chin Mylohyoid Line - insertion of Mylohyoid Mental Spines - origin of Geniohyoid

TEETH - on each side, top and bottom

2 Incisors 1 Canine 2 Premolars ("bicuspids") 3 Molars - not preceded by deciduous teeth

HYOID BONE

——————————————————————————————————————————————————————————————————————————————

JOINTS OF THE SKULL

Movement of Temporo-mandibular joint

- rotation to elevate and depress mandible - lateral displacement - protraction and retraction

Movements of Atlanto-occipital joint

Skull-atlas - flexion and extension

6 NOTES

7 8 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE POSTERIOR TRIANGLE

MUSCLE ORIGIN INSERTION ACTION/(NERVE) ——————————————————————————————————————————————————————————————————————————————

Splenius capitus Lower Ligamentum Back of mastoid Extends, rotates, nuchae and spines process, and and laterally of upper thoracic superior nuchal flexes head and vertebrae line neck (Dorsal rami of cervical Nn.)

Levator scapulae Transverse Upper border of Elevates scapula processes of the scapula (Ventral rami of cervicals 1-4 C3-5)

Scalenus anterior Transverse Scalene tubercle ┐ processes of of 1st rib │ cervical vertebrae │ 3-6 │ │ │ Elevate ribs, Scalenus medius Transverse 1st rib behind ├ and laterally processes of all groove for │ flex neck cervical vertebrae Subclavius │ (Ventral rami of │ cervical Nn.) │ Scalenus posterior Transverse Outer side of 2nd │ processes of rib ┘ cervical vertebrae 4-6

Sternocleido- By two heads from Short tendon to Flexes, rotates, mastoid anterior surface outer surface of and laterally of manubrium, and mastoid process flexes head and upper surface of and lateral 1/3 of neck; elevates clavicle superior nuchal sternum and ribs line (Spinal Accessory N.)

Platysma Skin and fascia of Lower border of Tenses skin of pectoral and mandible neck anterior deltoid (Facial N.) regions

Note: The posterior triangle is bounded by Trapezius posteriorly, Sternocleidomastoid anteriorly, and the clavicle inferiorly. It contains Semispinalis capitus, Splenius capitus, Levator scapulae, the scalenes, and Omohyoideus.

9 10 —————————————————————————————————————————————————————————————————————————————— PREVERTEBRAL MUSCLES

Longus capitus Transverse Occipital bone ┐ processes of │ middle 4 cervical │ vertebrae │ Flexes head ├ and neck │ (Ventral rami of Longus colli Bodies of upper Transverse │ cervical Nn.) thoracic and lower processes and │ cervical vertebrae bodies of upper │ cervical vertebrae ┘

11 12 —————————————————————————————————————————————————————————————————————————————— INFRAHYOID MUSCLES

Sternohyoid Back of manubrium Hyoid bone Depresses hyoid (Ansa cervicalis)

Sternothyroid Back of manubrium Thyroid cartilage Depresses thyroid cartilage (Ansa cervicalis)

Thyrohyoid Thyroid cartilage Hyoid bone Depresses hyoid (Hypoglossal N.)

Omohyoid Upper border of 2 bellies with an Depresses hyoid scapula and intermediate (Ansa cervicalis) suprascapular tendon passing ligament through a ligamentous pulley - inserts on hyoid bone

Note: The Ansa cervicalis is a LOOP formed by branches of the Hypoglossal N. and C2,3 anterior to the Carotid sheath, and lying on top of the Internal Jugular V. Branches run from the bottom of the loop to innervate Sternohyoid, Sternothyroid, and Omohyoid.

13 14 —————————————————————————————————————————————————————————————————————————————— SUPRAHYOID MUSCLES

Stylohyoid Styloid process Passes around Elevate and Digastric and retract hyoid inserts on greater (Facial N.) horn of hyoid bone

Mylohyoid Mylohyoid line of Body of hyoid bone Elevate hyoid mandible (Inferior alveolar N.)

Geniohyoid Mental spines of Body of hyoid bone Protracts hyoid mandible below (Hypoglossal N.) Genioglossus

Digastric Posterior belly Passes by Elevates hyoid; from mastoid intermediate depresses and notch of temporal tendon through retracts mandible bone Stylohyoid; (Facial and anterior belly Inferior alveolar inserts on Nn.) inferior surface of mandible near symphysis

Note: Mylohyoid forms the floor of the mouth and supports Geniohyoid, the muscles of the tongue, salivary glands, etc.

15 16 —————————————————————————————————————————————————————————————————————————————— FACIAL MUSCLES

Frontalis Anterior skull Skin over forehead Elevates eyebrows and eyebrows

Procerus Upper part of Skin over lower Depresses medial lateral nasal forehead part of eyebrows cartilages

Orbicularis oculi Ring of muscles encircling eyes Closes eye

Nasalis Maxilla above Lateral nasal Flares nostrils canine cartilage; part passes across bridge of nose

Levator labii Maxilla over the Orbicularis oris Elevates and superioris infraorbital everts upper lip foramen

Levator anguli Maxilla below Corners of Elevates and oris infraorbital orbicularis oris everts upper lip foramen

Zygomaticus minor Outer part of Skin and muscle of Elevates and zygomatic arch upper lip everts upper lip

Zygomaticus major Zygomatic arch Corners of Elevates upper lip orbicularis oris

Orbicularis oris Ring of muscles encircling mouth Closes mouth

Buccinator Outer part of Orbicularis oris Compresses cheeks posterior maxilla and mandible

Depressor anguli Outer surface of Corners of Depresses angles oris mandible orbicularis oris of mouth

Depressor labii Outer surface Skin over medial Depresses lower inferioris of mandible lower lip and lip orbicularis oris

Mentalis Mandible below Skin over chin Elevates skin over incisors chin and protrudes lower lip

Note: All muscles of the face are innervated by the Facial N.

Note: In the drawing, superficial muscles inserting into Orbicularis oris are oriented inferomedially, whereas deep muscles are oriented inferolaterally.

17 18 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF MASTICATION

Masseter Zygomatic arch Outer surface of Elevates and ramus of mandible protrudes mandible (Trigeminal N.)

Temporalis Fan-shaped area Coronoid process Elevates and on side of skull of mandible retracts mandible (Trigeminal N.)

Medial pterygoid Medial surface of Ramus of mandible Elevates and lateral pterygoid near angle laterally plate displaces mandible (Trigeminal N.)

Lateral pterygoid Lateral surface of Neck of mandible Protrudes mandible lateral pterygoid near articulation (Trigeminal N.) plate

Note: All muscles of mastication are innervated by branches of the Trigeminal N.

19 20 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE TONGUE

Styloglossus Styloid process Into side of Retracts and tongue elevates tongue (Hypoglossal N.)

Hyoglossus Hyoid bone Into side of Retracts and tongue depress tongue; deflects tongue to side (Hypoglossal N.)

Genioglossus Mental spines of Fan out beneath Retracts, mandible body of tongue protrudes, and depresses tongue (Hypoglossal N.)

Lingualis Muscular body of tongue that Changes shape of lies on top of Genioglossus tongue (Hypoglossal N.)

Note: All muscles of the tongue are innervated by the Hypoglossal N.

21 22 —————————————————————————————————————————————————————————————————————————————— EXTRINSIC MUSCLES OF THE EYE

Superior rectus ┐ ┌ Top of eyeball Turns eyeball up │ │ (Oculomotor N.) │ │ │ │ Inferior rectus │ │ Botton of eyeball Turns eyeball down │ │ (Oculomotor N.) │ Common │ │ tendinous │ Medial rectus ├ ring │ Medial side of Turns eyeball in │ around │ eyeball (Oculomotor N.) │ Optic N. at │ │ back of ┤ Lateral rectus │ orbit │ Lateral side of Turns eyeball out │ │ eyeball (Abducens N.) │ │ │ │ Superior oblique ┘ │ Passes through Turns eyeball down │ trochlea, then and out │ laterally under (Trochlear N.) │ Superior rectus, │ and inserts on │ upper lateral side └ of eyeball

Inferior oblique Lower medial Passes laterally Turns eyeball up anterior corner of under Inferior and out orbit rectus, and (Oculomotor N.) inserts on upper lateral side of eyeball

Levator palpebra Posterior roof Into upper eyelid Elevates upper superioris of orbit eyelid (Oculomotor N.)

Note: The obliques pass backward to the eyeball from the anterior medial corners of the orbit so they can turn the eyeball up and down.

23 CRANIAL NERVES

I - Olfactory N. - beneath the frontal lobe, it sends branches through cribriform plate into nasal cavity.

II - Optic N. - large nerve passing through optic canal and into eyeball.

III - Oculomotor N. - found in orbit, it innervates Superior, Inferior, and Medial rectus Mm., Levator palpebra, and Inferior oblique.

IV - Trochlear N. - found in orbit, it innervates Superior oblique.

V - Trigeminal N. - main nerve of deep face, divides into three divisions:

1 - Ophthalmic division - passes up into orbit through sup. orb. fissure.

A - Frontal N. - passes through top of orbit above eye, it exits supraorbital notch and becomes Supraorbital N., which passes up onto forehead.

2 - Maxillary division - deep in maxillary bone.

A - Infraorbital N. - exits infraorbital foramen with Infraobital A. to supply central part of face.

3 - Mandibular division - passes down to mandible.

A - Inferior alveolar N. - enters mandibular foramen and passes through mandible with Inferior alveolar A. It becomes Mental N. as it exits mental foramen to innervate chin.

B - Lingual N. - passes between tongue and mandible to supply tongue

VI - Abducens N. - found in orbit, it innervates Lateral rectus.

VII - Facial N. - emerges deep to parotid gland and divides into many branches which spread out over face and innervate facial muscles.

VIII - Vestibulocochlear N. - to inner ear deep in temporal bone.

IX - Glossopharyngeal N. - descends medial to styloid process, supplies Stylopharyngeus and back of pharynx and tongue.

X - Vagus N. - runs down neck with Internal jugular V. and Common carotid A.

XI - Accessory N. - pierces back of Sternocleidomastoid and crosses posterior triangle of neck to supply deep side of Trapezius.

XII - Hypoglossal N. - found near posterior belly of Digastricus, passes down and around External carotid A., then forward below tongue between Mylohyoid and Hyoglossus.

Note: Mnemonic - O, O, O, to touch and feel virgin girls' vagina and hymen!

24 ——————————————————————————————————————————————————————————————————————————————————————————————————— FUNCTIONS OF CRANIAL NERVES

CN # NAME SPECIAL SENSE SENSORY MOTOR PARASYMPATHETIC ———————————————————————————————————————————————————————————————————————————————————————————————————

I Olfactory Smell ------

II Optic Sight ------

III Oculomotor -- -- Most eye muscles Muscles of lens and iris

IV Trochlear -- -- Superior oblique --

V Trigeminal -- Face, mouth, Muscles of -- and 2/3 of mastication tongue

VI Abducens -- -- Lateral rectus --

VII Facial Taste 2/3 tongue -- Facial muscles Salivary and lacrimal glands

VIII Vestibulocochlear Hearing and ------equilibrium

IX Glossopharyngeal Taste 1/3 tongue 1/3 of tongue, Stylopharyngeus Parotid gland pharynx, middle ear

X Vagus -- Pharynx, larynx, Mm. of pharynx Viscera and viscera and larynx

XI Accessory -- -- Sternomastoid -- and trapezius

XII Hypoglossal -- -- Mm. of tongue --

———————————————————————————————————————————————————————————————————————————————————————————————————

Note: Mnemonic – Some say marry money, but my brother says big breasts matter most.

25 26 SPINAL NERVES OF THE HEAD AND NECK

I - Dorsal rami of Spinal Nn.

A - Suboccipital N. (C1) - found in suboccipital triangle with Vertebral A. Innervates rectus capitus posterior muscles and Obliquus capitus superior.

B - Greater occipital N. (C2) - pierces Semispinalis capitus near midline, then pierces Trapezius and runs up onto back of skull.

II - Ventral rami of Spinal Nn. (=Cervical Plexus).

A - Lesser occipital N. (C2,3) - found in posterior triangle between Levator scapulae and Scalenus medius, it passes up onto skull between external ear and Greater occipital N.

B - Great auricular N. (C2,3) - found in posterior triangle between Levator scapulae and Scalenus medius, it passes up over Sternocleidomastoid toward external ear.

C - Supraclavicular Nn. (C3,4) - found in posterior triangle between Levator scapulae and Scalenus medius, they passes down over clavicle.

D - Phrenic N. (C3-5) - descends neck on Scalenus anterior behind Internal jugular V., then passes into thorax behind first rib. In thorax it passes down to supply diaphragm.

III - Sympathetic trunk - deep to Carotid sheath lying on prevertebral muscles, it has a large cigar-shaped ganglion high in neck, a smaller ganglion at base of neck, and passes down into thorax.

27 ARTERIES OF THE HEAD AND NECK

28 ARTERIES OF THE HEAD AND NECK

I - Common carotid A. - large branch off Brachiocephalic trunk (right) or Aortic arch (left), passes up Carotid sheath with Internal jugular V., and divides into External and Internal carotid Aa.

A - External carotid A. - passes up side of neck and skull to temple.

1 - Superior thyroid A. - passes down to Thyroid gland.

2 - Lingual A. - passes anteriorly to tongue, then between Hyoglossus and Genioglossus.

3 - Facial A. - passes through Submandibular gland, then up onto face, and follows a sinuous path toward corner of mouth.

4 - Occipital A. - passes up posteriorly to back of skull, then accompanies Greater occipital N.

5 - Posterior auricular A. - passes up behind ear.

6 - Maxillary A. - large branch medial to mandible. It passes forward, sends a branch down to mandible, and continues into maxilla.

a - Inferior alveolar A. - branches off Maxillary A. near its beginning, and passes down into mandibular foramen, passes through mandible, exits mental foramen, and becomes Mental A. to supply chin.

b - Infraorbital A. - terminal branch of Maxillary A., it exits Infraorbital foramen with Infraorbital N.

7 - Superficial temporal A. - terminal branch of External carotid A. It passes up onto scalp.

a - Transverse facial A. - small branch, passes forward across Masseter below zygomatic arch.

B - Internal carotid A. - passes up into skull to supply brain.

1 - Ophthalmic A. - passes through Optic canal into orbit, supplies eye, and sends a branch through supraorbital foramen to become Supraorbital A.

a - Supraorbital A. - passes onto forehead with Supraorbital N.

Note: A mnemonic for the branches of the External carotid A. from inferior to superior is: Some like fast, others prefer much slower.

29 ARTERIES AND VEINS OF THE BRAIN

30 ARTERIES AND VEINS OF THE BRAIN

ARTERIES

I - Internal carotid A. - passes through Carotid canal and splits into:

A - Anterior cerebral A. - passes forward to supply medial surface and frontal pole of cerebral hemisphere.

1 - Anterior communicating A. - short transverse anastomosis between Anterior cerebral Aa.

B - Middle cerebral A. - passes laterally into lateral sulcus to supply superior and lateral surfaces and temporal pole of cerebral hemisphere.

II - Vertebral A. - passes through Foramen magnum, send off various cerebellar Aa. and joins opposite Vertebral A. to form Basilar A.

A - Cerebellar Aa. - pass laterally around cerebellum to supply it.

III - Basilar A. - unpaired median A. formed by union of Vertebral Aa.

A - Posterior cerebral A. - passes posteriorly and laterally to supply inferior surface and occipital pole of cerebral hemisphere.

B - Posterior communicating A. - small anastomosis passing anteriorly to Internal carotid A.

VEINS

I - Transverse sinuses - drain confluence of sinuses, pass laterally and forward through tentorium cerebri to Jugular foramina, and pass through to become Internal jugular Vv.

A - Superior sagittal sinus - drains veins along superior midline of brain and passes posteriorly and down to confluence of sinuses.

B - Straight sinus - drains veins along lower midline of brain and passes posteriorly to confluence of sinuses.

1 - Inferior sagittal sinus - drains veins along inferior border of falx cerebri, and empties into straight sinus.

2- Great cerebral V. - drains veins from midbrain and cerebellum.

Note: The Anterior and Posterior cerebral Aa. and Anterior and Posterior communicating Aa. form a Cerebral arterial circle (=Circle of Willis) around the hypophysis.

31 VEINS OF THE HEAD AND NECK

32 VEINS OF THE HEAD AND NECK

I - External jugular V. - formed by union of Posterior auricular V. and posterior division of Retromandibular V. It passes down neck over Sternocleidomastoid and empties into Subclavian V.

A - Posterior auricular V. - drains scalp behind ear.

B - Posterior division of Retromandibular V. - joins with Posterior auricular V. to form External jugular V.

1 - Retromandibular V. - formed by union of Maxillary V. and Superficial temporal V., passes through Parotid gland and bifurcates.

II - Internal jugular V. - continuation of Transverse sinus draining blood from brain. It receives blood from Common facial V. and passes down neck in Carotid sheath with Common carotid A. It empties into Subclavian V.

A - Common facial V. - formed by union of Facial V. and anterior division of Retromandibular V., it passes deep and dumps into Internal jugular V.

1 - Facial V. - drains face.

2 - Anterior division of Retromandibular V. - joins with Facial V. to form Common facial V.

a - Retromandibular V. - formed by union of Maxillary V. and Superficial temporal V., passes through Parotid gland and bifurcates.

Note: The back of the skull is drained by the Occipital V., that empties into the Deep cervical V. running down the back of the neck deep to Semispinalis capitus. At the base of the neck the Deep cervical V. empties into the Vertebral V.

33 CROSS-SECTION OF THE NECK

34 OSTEOLOGY OF THE POSTCRANIAL AXIAL SKELETON

VERTEBRAL COLUMN - consists of 5 regions

7 cervical vertebrae 12 thoracic vertebrae - bearing ribs 5 lumbar vertebrae 5 sacral vertebrae - fused to form Sacrum 4 coccygeal vertebrae - fused to form Coccyx - said to resemble Cuckoo's beak

PARTS OF VERTEBRAE

Body or centrum - bears weight; articulates with adjacent vertebrae Arch - encloses vertebral foramen, supports spinous and transverse processes and superior and inferior articular surfaces Vertebral foramen - for spinal cord Superior and inferior articular processes and surfaces - articulate with adjacent vertebrae Spinous process - for origin and insertion of muscles Transverse process - for origin and insertion of muscles; carry ribs in thoracic region Intervertebral disc - fibrous joint between vertebral centra

CERVICAL VERTEBRAE

All have transverse foramina (Foramina transversaria) for Vertebral A+V. C1 (=atlas) - articulates with occipital condyles C2 (=axis) - has odontoid process that permits atlas to rotate on axis C3-C5 have bifid spinous processes for Ligamentum nuchae

THORACIC VERTEBRAE

Costotransverse articulations - on transverse processes for tubercle of rib Superior and inferior costal articulations - on centrum for head of rib

LUMBAR VERTEBRAE

More robust than thoracic vertebrae. Do not carry ribs, but with large transverse process and mammillary processes for attachment of muscles.

SACRAL VERTEBRAE - Fused together to form sacrum

Body - fused bodies of centra of sacral vertebrae Alae - fused transverse processes of sacral vertebrae Auricular surface - articulates with pelvic bone Median Crest - fused spinous processes of sacral vertebrae Sacral Foramina - between transverse processes, for sacral spinal nerves

35 RIBS: True Ribs (pairs 1-7) False Ribs (pairs 8-12) Floating Ribs (pairs 11-12)

Head Superior and Inferior Articular Facets - articulate with vertebral centra Neck Tubercle - articulates with transverse process of vertebra Angle - lateral margin of erector spinae muscles Body Chondral (=sternal) end Costal cartilages - cartilaginous joint between rib and sternum

STERNUM

Manubrium Clavicular Notch - articulates with clavicle Body Xiphoid Process

JOINTS OF THE AXIAL SKELETON

Movements of Vertebral Column

Skull-atlas - flexion and extension Atlas-axis - rotation, slight flexion and extension All others - flexion and extension in sagittal plane - lateral flexion (in coronal plane) - rotation

Movements of Ribs

- swing out, up, and forward like bucket handle to elevate sternum and increase volume of ribcage

36 NOTES

37 38 —————————————————————————————————————————————————————————————————————————————— INTERMEDIATE MUSCLES OF THE BACK

Serratus posterior Spines of lower Lateral sides of Elevates ribs superior cervical and upper upper 3 or 4 ribs (2nd - 4th thoracic vertebrae intercostal Nn.)

Serratus posterior Spines of lower Lateral sides of Depresses ribs inferior thoracic and upper lower 3 or 4 ribs (9th - 11th lumbar vertebrae intercostal Nn.)

39 40 —————————————————————————————————————————————————————————————————————————————— ERECTOR SPINAE MUSCLES

Spinalis Spines of lower Spines of upper ┐ thoracic and upper thoracic vertebrae │ lumbar vertebrae │ │ │ Longissimus With entire By slips - medial │ thoracis Erector spinae to transverse │ group from spines processes of all 12 │ of sacral and thoracic vertebrae; │ Extend, lumbar vertebrae and lateral to all │ rotate, and and iliac crest 12 ribs │ laterally flex ├ vertebral │ column Longissimus Continuation of Tendon between │ (Dorsal rami capitus longissimus - from Splenius capitus │ of Spinal Nn.) transverse and Semispinalis │ processes of upper capitus, onto back │ thoracic and lower of mastoid process │ 4 cervical │ vertebrae │ │ │ Iliocostalis With entire By slips to back │ Erector spinae of all 12 ribs ┘ group from spines of sacral and lumbar vertebrae and iliac crest

Note: The three columns of muscle usually cannot be differentiated in the lumbar region and are best considered to be simply Erector spinae.

Note: The main function of these muscles is to maintain the curvatures of the spine and keep the trunk erect.

41 42 —————————————————————————————————————————————————————————————————————————————— TRANSVERSOSPINALIS MUSCLES

Semispinalis Transverse Between superior ┐ capitus processes of lower and inferior │ 4 cervical and nuchal lines on │ upper 6 thoracic skull; just deep │ vertebrae to Trapezius │ │ │ Semispinalis Articular Spans 3 to 6 │ cervicis processes of lower vertebrae and │ cervical vertebrae inserts of spines │ Extend, and transverse of cervical │ rotate, and processes of upper vertebrae │ laterally flex thoracic vertebrae ├ vertebral │ column │ (Dorsal rami Multifidus Transverse Spans 2 to 3 │ of Spinal Nn.) processes of vertebrae and │ vertebrae inserts on spines │ of vertebrae │ │ │ Rotatores Transverse Spans from one │ processes of vertebra to next │ vertebrae above, inserts on │ spine of vertebra ┘

------

Levator costae Transverse Passes laterally Elevate ribs processes of last and down to back (Dorsal ram cervical to 11th of next rib Spinal Nn.) thoracic vertebrae between angle and tubercle

Note: Levator costae is technically not a transversospinalis muscle, but was derived from them.

Note: All transversospinalis muscles originate on a transverse process and insert on a spinous process, hence the name. The transversospinalis muscles are best seen in different parts of the back: Semispinalis is best seen in the cervical region, Multifidus is best seen in the lumbar region, and Rotatores are best seen in the thoracic region.

43 44 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF SUBOCCIPITAL REGION

Obliquus capitis Transverse Occipital bone ┐ superior process of atlas │ │ │ Obliquus capitis Spine of axis Transverse process │ inferior of atlas │ Extend and ├ rotate head │ (Suboccipital Rectus capitus Spine of axis Occipital bone deep │ N.) posterior to Semispinalis │ major │ │ │ Rectus capitus Posterior tubercle Occipital bone deep │ posterior of atlas to Rectus major ┘ minor

Note: There are similar short muscles (Rectus capitus anterior and Rectus capitus lateralis) between the atlas and occipital bone on the anterior side. All of these muscles are primarily postural.

Note: The Greater occipital N. passes over these muscles and pierces Semispinalis capitus and trapezius. When Semispinalis capitus is reflected, the Greater occipital N. lies transversely on its deep surface. Also visible are the 3rd occipital N. and the Deep cervical V.

45 46 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE THORACIC WALL

External Lower border of Passes down and ┐ intercostals ribs medially to next │ lower rib │ │ │ Internal Lower border of Passes down and │ intercostals ribs laterally to next │ lower rib │ Move ribcage │ during active │ ├ respiration Innermost Same origin and insertion as internal │ (Intercostal intercostals intercostals; variable layer lying │ Nn.) over Intercostal NAV, may be difficult │ to differentiate from Internal │ intercostals │ │ │ Transversus Back of sternum Inner surface of │ thoracis costal cartilages ┘

Note: The ribcage is also moved directly by Serratus posterior superior and inferior, Levator costae, and the scalenes. Other muscles can also move the ribs during powerful respiration, e.g., Sternocleidomastoid, Rectus abdominus, etc.

47 48 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE ABDOMINAL WALL

External oblique Outer surface of Passes down and ┐ lower 8 ribs medially to iliac │ crest and linea │ alba │ Flex and │ laterally flex │ lumbar Internal oblique Thoracolumbar Passes up and │ vertebrae; fascia, iliac medially to lower │ compress crest, and 3 ribs and linea ├ abdomen to inguinal ligament alba (splits │ expel contents; around Rectus │ obliques are abdominus) │ main rotators │ of lumbar spine │ (Ventral rami of Transversus Deep on costal Aponeurosis of │ lower thoracic abdominus cartilages, iliac internal │ and first lumbar crest, and intercostal ┘ Nn.) inguinal ligament

Rectus abdominus Pubic symphysis Sternum and lower Flex lumbar spine, and pubic crest costal cartilages compress abdomen (Ventral rami of lower thoracic Nn.)

Note: A important function of the muscles of the abdominal wall is support the viscera against the pull of gravity.

49 MUSCLES OF THE PELVIS

50 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE PELVIS

Iliacus Iliac fossa Passes down to Flexes hip insert on lesser (Femoral N.) trochanter of femur with Psoas major

Psoas major Bodies of the Passes beneath Flexes hip lumbar vertebrae inguinal ligament (2nd and 3rd to insert on lumbar Nn.) lesser trochanter of femur with Iliacus

Psoas minor Bodies of the Iliopubic eminence Flexes lumbar last thoracic and near acetabulum vertebrae first lumbar (Ventral ramus of vertebrae L1)

Quadratus lumborum Iliac crest and Transverse Flexes lumbar transverse processes of vertebrae processes of lower upper lumbar laterally lumbar vertebrae vertebrae and (Ventral rami of last rib Subcostal N. and L1-3 or 4)

Note: Psoas minor is small, and is absent in 40% of individuals.

Note: Iliacus and Psoas major are discussed on p. 103 as Iliopsoas.

51 MUSCLES OF THE PERINEUM

52 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE PERINEUM - MALE

Bulbospongiosus Central tendon of Pubic arch, Compresses bulb of perineum and urogenital corpus spongiosum median raphe with diaphragm, and during micturation opposite dorsum of penis and ejaculation; Bulbospongiosus compresses Dorsal V. of penis (Pudendal N.)

Ischiocavernosus Medial side of Pubic arch on Compresses crus of ischial tuberosity side of crus of penis to erect penis (Pudendal N.)

Transversus Medial side of Central tendon of Stabilizes central perinei ischial tuberosity perineum near anus tendon of perineum (Pudendal N.)

—————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE PERINEUM - FEMALE

Bulbospongiosus Central tendon of Pubic arch, and Sphincter of perineum root and dorsum vagina; compresses of clitoris Dorsal V. of clitoris (Pudendal N.)

Ischiocavernosus Medial side of Pubic arch on Compresses crus of ischial tuberosity side of crus of clitoris to erect clitoris (Pudendal N.)

Transversus Medial side of Central tendon of Stabilizes central perinei ischial tuberosity perineum tendon of perineum (Pudendal N.)

Note: The central tendon of the perineum is a muscular/fibrous band extending anteriorly on the midline from the anus to the urogenital diaphragm.

53 NOTES

54 NERVES OF THE THORAX

I - Cranial Nerves

A - Vagus N. - passes down neck into mediastinum, in front of Aortic arch and sends off Recurrent laryngeal N., then continues behind heart to form plexus around the esophagus.

1 - Recurrent laryngeal N. - passes behind Brachiocephalic trunk on right and Aortic arch on left, then up neck. Note they begin at a different level on each side.

II - Cervical Plexus

A - Phrenic N. - passes down neck, on side of fibrous pericardium, in front of root of lung, pierces diaphragm and supplies its ventral surface.

III - Spinal Nerves

A - Intercostal Nn. - ventral rami of Spinal Nn. T1-T11. They run laterally between ribs to supply thoracic wall.

IV - Sympathetic Trunk - continuation of trunk from neck, descends thorax on either side of vertebral column. Has 11 ganglia in thorax which give it a lumpy appearance.

A - Greater splanchnic N. - main visceral branch of Sympathetic trunk. It passes anteriorly and inferiorly on side of vertebral column, pierces the diaphragm, and ends in large Celiac ganglion, which in turn sends branches to the abdominal viscera.

55 NERVES OF THE THORAX AND ABDOMEN

56 NERVES OF THE ABDOMEN

I - Lumbar Plexus - ventral rami of L1-L4

A - Subcostal N. (T12) - runs laterally below 12th rib.

B - Iliohypogastric N. (L1) - runs laterally from behind Psoas major to innervate lateral gluteal region.

C - Ilioinguinal N. (L1) - runs laterally from behind Psoas major and inferior to Iliohypogastric N., and innervates pubic region.

D - Lateral cutaneous N. of thigh (L2,3) - passes laterally over Iliacus below Ilioinguinal N. to innervate skin of anterolateral thigh.

E - Femoral N. (L2-4) - large; passes over Iliacus and under inguinal ligament to innervate anterior thigh.

F - Genitofemoral N. (L1,2) - pierces Psoas major and passes down on top of it. Innervates scrotum/labium majus and skin of anteromedial thigh.

G - Obturator N. (L2-4) - medial to Psoas major, deep in pelvis, passes into thigh under inguinal ligament and innervates adductors.

H - Lumbosacral Trunk (L4,5) - contributes to Sciatic N.

II - Sacral Plexus - ventral rami of L4-S4

A - Superior gluteal N. (L4-S1)- passes back to innervate Gluteus minimus and medius and Tensor fasciae latae.

B - Inferior gluteal N. (L5-S2) - passes back to innervate Gluteus maximus.

C - Pudendal N. (S2-4) - passes back to innervate perineal muscles and skin of perineal region.

D - Sciatic N. (L4-S4) - formed by the union of the Lumbosacral Trunk (L4,5) with S1-4, passes down into thigh and innervates posterior thigh and leg and foot.

III - Sympathetic Trunk - continues down on either side of vertebral column from thorax through lumbar region. May be difficult to find behind Abdominal Aorta and Inferior Vena Cava.

Note: Iliohypogastric and Ilioinguinal Nn. may run together for some distance.

Note: Mnemonics for branches of lumbar plexus are: "Some India inks last for generations or longer" and "Should I initiate long fornication given only lust?", the latter thanks to a former student.

57 ARTERIES OF THE THORAX AND ABDOMEN

58 ARTERIES OF THE THORAX AND ABDOMEN

Ia - Ascending Aorta, Aortic Arch, and Descending Aorta in thorax.

A - Subclavian A.

1 - Internal thoracic A. - descends inside thoracic wall behind Transversus thoracis. Divides at 6th rib into:

a - Superior epigastric A. - pierces diaphragm and runs down Rectus sheath, anastomose with Inferior epigastric A.

b - Musculophrenic A. - runs laterally on diaphragm.

B - Intercostal Aa. - pass laterally from Aorta between ribs.

Ib - Abdominal Aorta - continuation of Descending Aorta in abdomen.

A - CELIAC TRUNK - unpaired visceral branch supplying liver, spleen, and stomach. See p. 61 for branches.

B - SUPERIOR MESENTERIC A. - unpaired visceral branch supplying small intestine and part of colon. See p. 61 for branches.

C - Suprarenal Aa. - small, pass to suprarenal glands.

D - Renal Aa. - large; pass laterally to kidneys.

E - Testicular/Ovarian Aa. - pass down over Psoas major to gonads.

F - Lumbar Aa. - pass laterally to abdominal wall.

G - INFERIOR MESENTERIC A. - unpaired visceral branch supplying part of colon and rectum. See p. 61 for branches.

H - Median sacral A. - passes down over sacrum between Common iliac Aa.

I - Common iliac Aa. - terminal branches, pass inferolaterally to supplu lower extremilty.

1 - External iliac A. - passes down to thigh and becomes Femoral A.

a - Inferior epigastric A. - branches off just above inguinal ligament, passes medially, then up rectus sheath.

2 - Internal iliac A. - passes down into pelvis.

a - Superior gluteal A. - passes back to gluteal region between Lumbosacral trunk and 1st sacral ramus.

b - Inferior gluteal A. - passes back to gluteal region between 1st and 3rd sacral rami.

c - Obliterated umbilical A. - fetal terminal branch, in adults a fibrous cord passing up abdominal wall to umbilicus.

59 UNPAIRED VISCERAL BRANCHES OF THE ABDOMINAL AORTA

60 UNPAIRED VISCERAL BRANCHES OF THE ABDOMINAL AORTA

A - CELIAC TRUNK - unpaired visceral branch supplying liver, spleen, and stomach.

1 - Common hepatic A. - passes toward liver and gives off:

a - Gastroduodenal A. - passes to end of stomach and sends off:

i - Right Gastroepiploic A. - passes along greater curvature of stomach and anastomoses with Left gastroepiploic A.

b - Hepatic (Proper) A. - passes up to liver and splits into:

i - Right hepatic A. - enters Porta hepatis to supply liver.

ii - Left hepatic A - enters Porta hepatis to supply liver.

iii - Cystic A. - passes to gall bladder.

c - Right gastric A. - passes down to stomach and then along lesser curvature of stomach; anastomoses with Left gastric A.

2 - Splenic A. - passes left over to spleen; sends off:

a - Left gastroepiploic A. - passes along greater curvature of stomach and anastomoses with Right gastroepiploic A.

3 - Left gastric A. - passes along lesser curvature of stomach and anastomoses with Right gastric A.

B - SUPERIOR MESENTERIC A. - unpaired visceral branch supplying small intestine and part of colon.

1 - Intestinal Aa. - 10-16 branches pass into mesentery to supply jejunum and ileum. Interconnected by anastomosing arcades.

a - Vasa recta - small straight vessels passing from ends of anastomosing Intestinal Aa. to small intestine.

2 - Ileocolic A. - passes down to junction of ileum and colon.

3 - Right colic A. - passes right to ascending colon.

4 - Middle colic A. - passes up to transverse colon.

G - INFERIOR MESENTERIC A. - unpaired visceral branch supplying part of colon and rectum.

1 - Left colic A. - passes left to descending colon.

2 - Sigmoid Aa. - usually 2 or 3, pass down to sigmoid colon.

3 - Superior rectal A. - passes down to rectum.

61 VEINS OF THE THORAX AND ABDOMEN

62 VEINS OF THE THORAX AND ABDOMEN

I - Superior Vena Cava - drains head, arms, and thorax and passes down to heart.

A - Brachiocephalic Vv. - drain blood from Subclavian V. and Jugular V.

1 - Left superior intercostal V. - union of 2nd and 3rd intercostal Vv., drains into Left Brachiocephalic V.

B - Azygos V. - on right side of spinal column, it drains Right intercostal Vv., Hemiazygos V. and Accessory hemiazygos V. It passes up and dumps into Superior Vena Cava from behind.

1 - Hemiazygos V. - drains lower Intercostal Vv. on left side.

2 - Accessory hemiazygos V. - drains upper Intercostal Vv. on left side.

3 - Intercostal Vv. - on right side they drain into Azygos V.; on left they drain into Hemiazygos and Accessory hemiazygos Vv.

II - Inferior Vena Cava - drains abdomen and legs, and passes up to heart.

A - Hepatic Vv. - three or so short veins from back of liver.

III - Hepatic Portal V. - large vein entering Porta hepatis. It drains venous blood from organs to liver.

A - Splenic V. - drains blood from spleen.

B - Superior mesenteric V. - large; drains blood from Ascending and Transverse colon and small intestine.

C - Inferior mesenteric V. - drains blood from descending and sigmoid colon.

D - Gastric V. - drains blood from stomach; may empty into Splenic or Hepatic portal V.

Note: The Left testicular/ovarian V. usually empties into the Left renal V. rather than the Inferior Vena Cava.

Note: The Thoracic Duct lies between the Descending Aorta and Azygos V. and drains lymph and chyle from the Cisterna chyli up to dump into the union of the L. Internal jugular V. and the L. Subclavian V.

63 OSTEOLOGY OF THE PECTORAL GIRDLE AND UPPER EXTREMITY

CLAVICLE

Sternal Articular Surface - articulates with sternum Acromial Articular Surface - articulates with acromion process Conoid Tubercle - attachment for conoid part of Coracoclavicular Ligament

SCAPULA

Supraspinous Fossa - origin of Supraspinatus Infraspinous Fossa - origin of Infraspinatus, Teres major, and Teres minor Subscapular Fossa - origin of Subscapularis Spine - insertion of Trapezius Vertebral border - insertion of Rhomboideus major and minor, and Serratus anterior Coracoid Process - origin of Coracobrachialis, and Biceps brachii short head; insertion of Pectoralis minor, and attachment for trapezoid part of Coracoclavicular Ligament Acromion Process - roofs over shoulder joint and articulates with clavicle Glenoid fossa - articulates with humerus Supraglenoid Tubercle - origin of Biceps brachii long head Infraglenoid Tubercle - origin of Triceps brachii long head

HUMERUS

Head - articulates with scapula Anatomical Neck - margin of articular surface of head Surgical Neck - where humerus often breaks Greater Tubercle - insertion of Supraspinatus, Infraspinatus, and Teres minor Lesser Tubercle - insertion of Subscapularis Intertubercular Sulcus (=Bicipital Groove) - groove for tendon of Biceps brachii long head; Latissimus dorsi, Teres major, and Pectoralis major insert on its sides Deltoid Tuberosity - insertion of Deltoideus Radial (=Spiral) Groove - for Radial N. between medial and lateral heads of Triceps brachii Capitulum - articulates with radius Trochlea - articulates with ulna Medial Epicondyle - origin of flexors of forearm Lateral Epicondyle - origin of extensors of forearm Olecranon Fossa - receives olecranon process on extension of elbow Coronoid Fossa - receives coronoid process on flexion of elbow

ULNA

Olecranon Process - insertion of Triceps brachii Trochlear Notch - articulates with trochlea of humerus Coronoid Process - forms inferior margin of trochlear notch Radial Notch - articulates with proximal end of radius Ulnar Tuberosity - insertion of Brachialis Styloid Process - attachment of ligaments

64 RADIUS

Head - articulates with humerus and ulna Fovea capitis - depression for capitulum of humerus Radial Tuberosity - insertion of Biceps brachii Styloid Process - attachment of ligaments Ulnar Notch - articulates with distal end of ulna Lower Articular Facet - articulates with scaphoid and lunate

CARPUS

Scaphoid Mnemonics for these, Sally Some Lunate proximal thumbside to Lowers Lovers Triquetrum digit V side, then Tom's Try Pisiform distal thumbside to Pants Positions Trapezium digit V side are: Then That Trapezoid Things They Capitate Can Can't Hamate Happen Handle

METACARPALS I-V AND PHALANGES

Digit I (=Pollex) has: Proximal and Distal Phalanges Digits II-V have: Proximal, Middle, and Distal Phalanges

JOINTS OF THE UPPER EXTREMITY

Movements of scapula

- upward and downward rotation - elevation and depression - protraction and retraction

Movements of shoulder joint

- flexion and extension - aBduction and adduction - medial and lateral rotation

Movements of forearm

- flexion and extension - Pronation and supination

Movements of wrist and hand

- adduction and abduction at radio-carpal joint - extension at radio-carpal joint - flexion at intercarpal joint - flexion and extension of carpo-metacarpal joints - opposition of pollex by rotation - flexion and extension of metacarpo-phalangeal joints

65 66 —————————————————————————————————————————————————————————————————————————————— MUSCLES ATTACHING UPPER EXTREMITY TO TRUNK - ANTERIOR SIDE

Serratus anterior Slips from outer Passes between Protracts and surface of upper ribs and scapula rotates scapula eight ribs to vertebral upward, elevates border of scapula ribs (Long thoracic N.)

Pectoralis minor Outer surface of Coracoid procces Depresses scapula ribs 3-5 of scapula (Medial pectoral N.)

Pectoralis major Clavicular head - Bicipital groove Adducts and medial 1/2 of of humerus medially rotates clavicle shoulder (Lateral and Sternal head - Medial pectoral sternum and upper Nn.) 6 cartilages

67 68 —————————————————————————————————————————————————————————————————————————————— MUSCLES ATTACHING UPPER EXTREMITY TO TRUNK - POSTERIOR SIDE

Trapezius Skull, and all Lateral 1/3 of Elevates, cervical and clavicle, spine of depresses, thoracic vertebrae scapula retracts, and rotates scapula up and down (Spinal accessory N.)

Levator scapulae Transverse Upper angle of Elevates and processes of C1-4 scapula rotates scapula downward (Dorsal scapular N.)

Rhomboideus minor Spines of C7-T1 Upper part of Elevates, and lower part of vertebral border retracts and Ligamentum of scapula rotates scapula nuchae downward (Dorsal scapular N.)

Rhomboideus major Spines of T1-4 Lower part of Elevates, vertebral border retracts and of scapula rotates scapula downward (Dorsal scapular N.)

Latissimus dorsi Aponeurosis from Passes under Adducts, extends, lower 6 thoracic axilla, inserts in and medially vertebrae, lumbo- bicipital groove rotates shoulder sacral fascia, (Thoracodorsal N.) iliac crest and lower 3 or 4 ribs

69 70 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE SHOULDER JOINT - SCAPULAR MUSCLES

Subscapularis Subscapular fossa Passes in front of Medially rotates joint to lesser shoulder tubercle of (Upper subscapular humerus N.)

Supraspinatus Supraspinous fossa Passes above joint ABducts shoulder to greater (Suprascapular N.) tubercle of humerus

Infraspinatus Infraspinous fossa Passes behind Laterally rotates joint to greater shoulder tubercle of (Suprascapular N.) humerus

Teres minor Upper 2/3 of Passes behind Laterally rotates lateral border of joint to greater shoulder scapula tubercle of (Axillary N.) humerus

Teres major Inferior angle of Medial lip of Adducts and scapula bicipital groove medially rotates near Latissimus shoulder dorsi (Lower subscapular N.)

Deltoideus Lateral 1/3 of Deltoid tuberosity Flexes, aBducts, clavicle, upper of humerus and extends surface of shoulder acromion, spine of (Axillary N.) scapula

Note: Subscapularis, Supraspinatus, Infraspinatus, and Teres minor together form the "Rotator Cuff", and share the common function of holding the head of the humerus in the glenoid fossa.

Note: Deltoideus cannot initiate aBduction of the shoulder, but Supraspinatus can.

71 72 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE ARM

Biceps brachii Short head - By tendon on back Flexes elbow and coracoid process of tuberosity of supinates forearm of scapula (w/ radius; tendon of (Musculocutaneous Coracobrachialis) long head runs in N.) bicipital groove Long head - supraglenoid tubercle of scapula

Coracobrachialis Coracoid process Middle of medial Flexes and adducts of scapula border of humerus shoulder (w/ Biceps (Musculocutaneous brachii - short) N.)

Brachialis Lower 2/3 of By tendon to Flexes elbow anterior humerus tuberosity of ulna (Musculocutaneous N.)

Triceps brachii Long head - Upper surface of Extends elbow infraglenoid olecranon (Radial N.) tubercle of scapula

Medial head - posterior surface of humerus below spiral groove

Lateral head - posterior and lateral surface of humerus above spiral groove

Anconeus Lateral epicondyle Lateral surface of Extends elbow of humerus olecranon and ulna (Radial N.)

Note: Biceps brachii also inserts by way of the bicipital aponeurosis into the deep fascia over the origin of the flexors of the wrist and hand. The aponeurosis can be palpated easily in the living.

Note: Anconeus can be considered a detached part of Triceps brachii.

73 74 —————————————————————————————————————————————————————————————————————————————— SUPERFICIAL EXTENSORS OF THE FOREARM

Extensor carpi Lateral Base of metacarpal Extends and radialis supracondylar II aBducts wrist longus ridge of humerus (Radial N.)

Extensor carpi Lateral epicondyle Base of metacarpal Extends and radialis of humerus III aBducts wrist brevis (Deep radial N.)

Extensor digitorum Lateral epicondyle By four tendons Extends digits communis of humerus to extensor II-V expansions of (Deep radial N.) digits II-V

Extensor digiti Lateral epicondyle Extensor expansion Extends digit V minimi of humerus of digit V (Deep radial N.)

Extensor carpi Lateral epicondyle Base of metacarpal Extends and ulnaris of humerus, and V adducts wrist posterior border (Deep radial N.) of ulna

Note: Extensor carpi radialis, Extensor digitorum communis, and Extensor digiti minimi originate by a common tendon from the lateral epicondyle.

Note: All extensors except Extensor carpi radialis longus are innervated by the Deep Radial N.

75 76 —————————————————————————————————————————————————————————————————————————————— DEEP EXTENSORS OF THE FOREARM

ABductor pollicis Middle 1/3 of back Base of metacarpal ABducts pollex and longus of ulna, radius, I wrist and interosseus (Deep radial N.) membrane

Extensor pollicis Back of radius and Base of proximal Extends pollex brevis interosseus phalanx of digit I (Deep radial N.) membrane

Extensor pollicis Middle 1/3 of back Base of distal Extends pollex longus of ulna and phalanx of digit I (Deep radial N.) interosseus membrane

Extensor indicis Back of ulna and Extensor expansion Extends index interosseus of digit II finger membrane near (Deep radial N.) distal end

Note: The tendons of Extensor pollicis longus and brevis bound the Anatomical Snuffbox.

Note: All extensors except Extensor carpi radialis longus are innervated by the Deep Radial N.

77 78 —————————————————————————————————————————————————————————————————————————————— SUPERFICIAL FLEXORS OF THE FOREARM

Flexor carpi Medial epicondyle Bases of Flexes wrist radialis of humerus metacarpals II-III (Median N.)

Palmaris longus Medial epicondyle Palmar aponeurosis Flexes wrist of humerus (Median N.)

Flexor carpi Medial epicondyle Pisiform, hamate, Flexes and ulnaris of humerus and base of adducts wrist metacarpal V (Ulnar N.)

Note: Palmaris longus is absent in 10% of individuals. The trait is genetically controlled, and absence of the muscle is dominant.

79 80 —————————————————————————————————————————————————————————————————————————————— DEEP FLEXORS OF THE FOREARM

Flexor digitorum Medial epicondyle By four tendons Flex digits II-V superficialis of humerus, to 2nd phalanges (Median N.) coronoid process of digits II-V of ulna, and (Tendons split oblique line of near insertion radius to allow Flexor digitorum profundus to pass through)

Flexor digitorum Middle 2/3 of By four tendons Flex digits II-V profundus ulna and to distal (Median and Ulnar interosseus phalanges of Nn.) membrane digits II-V

Flexor pollicis Middle 2/3 of Base of distal Flexes pollex longus radius and phalanx of (Median N.) interosseus thumb membrane

81 82 —————————————————————————————————————————————————————————————————————————————— OTHER MUSCLES OF THE FOREARM

Brachioradialis Lateral Styloid process of Flexes elbow supracondylar radius (Radial N.) ridge of humerus

Supinator By 2 heads, from Anterior and Supinates forearm lateral epicondyle lateral surface (Deep radial N.) of humerus and of radius supinator crest of ulna

Pronator teres Medial epicondyle Middle of lateral Pronates forearm of humerus, and surface of radius (Median N.) coronoid process of ulna

Pronator quadratus Distal 1/4 of Distal 1/4 of Pronates forearm front of ulna lateral surface (Median N.) of radius

Note: Brachioradialis can assist in supination of a pronated forearm, and used to be called "supinator longus".

83 84 —————————————————————————————————————————————————————————————————————————————— THENAR MUSCLES

ABductor pollicis Flexor retinaculum Radial side of ABducts pollex brevis and adjacent base of 1st (Median N.) carpals phalanx of digit I

Opponens pollicis Flexor retinaculum Radial side of Flexes metacarpal and adjacent metacarpal I I; rotates carpals. Found metacarpal to deep to ABductor oppose pollicis brevis (Median N.)

Flexor pollicis Flexor retinaculum Base of 1st Flexes pollex brevis and adjacent phalanx of digit I (Median N.) carpals

—————————————————————————————————————————————————————————————————————————————— HYPOTHENAR MUSCLES

ABductor digiti Pisiform and Ulnar side of base ABducts digit V minimi adjacent ligaments of 1st phalanx of (Ulnar N.) digit V

Opponens digiti Flexor retinaculum Ulnar side of Rotates metacarpal minimi and hook of hamate metacarpal V V (Ulnar N.)

Flexor digiti Flexor retinaculum Base of 1st Flexes digit V minimi and hook of hamate phalanx of digit V (Ulnar N.)

85 86 —————————————————————————————————————————————————————————————————————————————— OTHER MUSCLES OF THE HAND

Lumbricales (4) From sides of four Tendon into Flex digits II-V tendons of Flexor extensor at metacarpo- digitorum expansions of phalangeal joints profundus digits II-V and extend at interphalangeal joints (Usually 1st and 2nd by Median N.; 3rd and 4th by Ulnar N.)

Palmaris brevis Ulnar border of Skin of medial Wrinkles skin of palmar aponeurosis (=ulnar) side of medial side of and front of hand palm to deepen flexor retinaculum hollow of hand (Ulnar N.)

Adductor pollicis Metacarpal III and Ulnar side of base Adducts pollex adjacent carpals of 1st phalanx of (Ulnar N.) digit I

Palmar interossei By 1 head from Into bases of 1st Adduct digits II, (3) side of metacarpal phalanges; on IV, and V toward they act on medial side of axis of digit III digit II, and (Ulnar N.) lateral sides of digits IV-V

Dorsal interossei Each by 2 heads, Into bases of 1st ABduct digits (4) from sides of phalanges; II-IV from axis of adjacent on lateral sides digit III metacarpals I-V of digits II-III (Ulnar N.) and medial sides of digits IV and V

Note: PAD (Palmar ADduct) and DAB (Dorsal ABduct) are words.

87 BRACHIAL PLEXUS

88 BRACHIAL PLEXUS

I - ROOTS - Ventral rami of Spinal Nn. C5-T1

A - Long thoracic N. - branches off roots C5-C7 of brachial plexus, and passes down to Serratus anterior deep to Pectoralis major.

II - TRUNKS - Upper, Middle, and Lower Trunks formed from roots.

A - Suprascapular N. - arises from upper trunk; can be found deep near Omohyoideus, it passes under suprascapular ligament into supraspinous fossa where it is found with Suprascapular A.

III - DIVISIONS - Anterior and Posterior Divisions of each trunk.

IV - CORDS

A - Lateral Cord - from anterior division of upper and middle trunks.

B - Posterior Cord - from posterior divisions of each trunk.

C - Medial Cord - anterior division of lower cord.

V - BRANCHES

A - Musculocutaneous N.

B - Median N. (formed from medial and lateral roots)

C - Axillary N.

D - Radial N.

E - Ulnar N.

Note: The mnemonic for the arrangement of the brachial plexus is:

Roots Robert Trunks Taylor Divisions Drinks Cords Cold Branches Beer

89 NERVES OF THE UPPER EXTREMITY

90 NERVES OF THE UPPER EXTREMITY

Ia - Lateral cord

A - Lateral pectoral N. - passes medial to Pectoralis minor and ends in Pectoralis major.

B - Lateral root of Median N. - joins medial root to form Median N.

Ib - Musculocutaneous N. - continuation of Lateral Cord, pierces Coracobrachialis and descends arm between Biceps brachii and Brachialis. At elbow becomes Lateral cutaneous N. of forearm.

IIa - Medial cord

A - Medial pectoral N. - pierces Pectoralis minor and ends in Pectoralis major.

B - Medial root of Median N. - joins lateral root to form Median N.

IIb - Ulnar N. - continuation of Medial Cord. Passes down arm with Brachial A., then behind medial epicondyle, and down forearm with Ulnar A.

A - Palmar digital branches of Ulnar N. - pass across palm to digits IV-V.

IIIa - Posterior cord - lies behind Axillary A.

A - Upper subscapular N. - arises in axilla, passes to Subscapularis.

B - Thoracodorsal N. - arises between Upper and Lower subscapular Nn. and passes with Thoracodorsal A+V to Latissimus dorsi.

C - Lower subscapular N. - arises near Axillary N., passes to Teres maj.

D - Axillary N. - large branch, passes behind humerus and through quadrangular space with Posterior humeral circumflex A+V.

IIIb - Radial N. - continuation of Posterior Cord. Passes behind humerus with Profunda brachii A., then anterior to lateral epicondyle, and splits into Superficial and Deep Radial Nn.

A - Superficial radial N. - passes down forearm deep to Brachioradialis. At wrist it passes onto dorsum of hand.

1 - [Dorsal] digital Nn. - small branches passing along digits.

B - Deep radial N. - Pierces Supinator and passes down extensor side of forearm deep to Extensor digitorum communis.

IV - Median N. - Descends arm with Brachial A., and passes down forearm deep to Flexor digitorum superficialis.

A - Palmar digital branches of Median N. - cross palm to digits I-IV.

B - Recurrent branch of median N. - passes laterally to thenar muscles.

Note: Long thoracic N. off roots C5-C7 and Suprascapular N. off Upper Trunk were described on p. 89.

91 ARTERIES OF THE UPPER EXTREMITY

92 ARTERIES OF THE UPPER EXTREMITY - SHOULDER REGION

Ia - Subclavian A. - passes laterally from Brachiocephalic trunk or Aortic arch to supply arm. At lateral border of 1st rib becomes Axillary A.

A - Vertebral A. - passes up through Foramina transversaria of cervical vertebrae, through Suboccipital triangle, and into skull.

B - Thyrocervical trunk - short branch from top of Subclavian A.

1 - Inferior thyroid A. - passes up neck behind Carotid sheath to Thyroid gland.

2 - Suprascapular A. - passes over Suprascapular Ligament and into supraspinous fossa, a branch then passes laterally into infraspinous fossa.

3 - Transverse cervical A. - passes down to vertebral border of scapula, and anastomoses with Suprascapular and Circumflex scapular Aa.

C - Internal thoracic A. - branches off opposite Thyrocervical trunk and passes down into thorax.

D - Costocervical trunk - branches off back of Subclavian A. and sends branches up neck and down into thorax.

Ib - Axillary A. - continuation of Subclavian A. after first rib. After passing inferior border of Teres major it becomes Brachial A.

A - Thoracoacromial A. - branches off Axillary A. medial to Pectoralis minor and branches on deep surface of Pectoralis major.

B - Lateral thoracic A. – arises deep to Pectoralis minor and passes down lateral border of Pectoralis minor to supply muscles and mammary gland.

C - Subscapular A. - short medial branch opposite Humeral circumflex Aa. It divides into Circumflex scapular A. and Thoracodorsal A.

1 - Circumflex scapular A. - passes backward into triangular space, enters infraspinous fossa and anastomoses with Transverse cervical A. and Suprascapular A.

2 - Thoracodorsal A. - passes down thoracic wall with Thoracodorsal N. to Latissimus dorsi.

D - Anterior humeral circumflex A. - small branch opposite Subscapular A., passes laterally around humerus.

E - Posterior humeral circumflex A. - large branch opposite Subscapular A., passes laterally behind humerus with Axillary N. through quadrangular space.

93 ARTERIES OF THE UPPER EXTREMITY - ARM, FOREARM, AND HAND

I - Brachial A. - continuation of Axillary A. after distal border of Teres major. Passes down in front of humerus. In cubital fossa it splits into Ulnar and Radial Aa.

A - Profunda brachii A. - passes down upper arm deep behind humerus with Radial N.

B - Superior ulnar collateral A. - passes down with Ulnar N. behind medial epicondyle, and anastomoses with Posterior ulnar recurrent A.

C - Inferior ulnar collateral A. - branches off Brachial A. about 5 cm above elbow, passes down to medial epicondyle and anastomoses with Anterior ulnar recurrent A.

D - Radial A. - passes down anterior to radius with Superficial radial N. Passes behind metacarpal I through "Anatomical Snuffbox", and goes deep to form Deep palmar arterial arch.

1 - Radial recurrent A. - arises in cubital fossa and passes up arm to anastomose with Profunda brachii A.

2 - Deep palmar arterial arch - runs deep across palm to Ulnar A. and sends off branches to Palmar metacarpal Aa.

E - Ulnar A. - passes down anterior to ulna with Ulnar N. On palm forms Superficial palmar arterial arch.

1 - Anterior and posterior ulnar recurrent Aa. - arise in cubital fossa and pass up to anastomose with Inferior and Superior ulnar collateral Aa., respectively.

2 - Common interosseus A. - short branch arising below cubital fossa.

a - Anterior interosseus A. - descends forearm between radius and ulna anterior to interosseus membrane.

b - Posterior interosseus A. - descends forearm between radius and ulna posterior to interosseus membrane.

c - Interosseus recurrent A. - passes up arm and anastomoses with Profunda brachii A.

3 - Superficial palmar arterial arch - passes across palm to connect with Radial A.

a - Palmar metacarpal Aa. - branch off Deep and Superficial palmar arterial arches and pass down palm over metacarpals, then divide into Palmar digital Aa.

i - Palmar digital Aa. - pass along each side of digits.

Note: Suppose infant is a mnemonic for the collaterals and recurrents of the elbow.

94 CUTANEOUS VEINS OF THE UPPER EXTREMITY

I - Basilic V. - passes from dorsum of hand, up medial side of arm to elbow, there it is connected to Cephalic V. by Median cubital V. It continues up arm,and halfway up arm it goes deep and runs with Brachial A. It becomes Axillary V. at distal border of Teres major.

A - Median cubital V. - runs transversly in cubital fossa and connects Basilic and Cephalic Vv.

1 - Median V. of forearm - variable, passes up forearm from palm and dumps into Median cubital V. in cubital fossa.

B - Dorsal venous arch - variable, on dorsum of hand, it drains blood from digital veins and in turn drains into Basilic and Cephalic Vv.

II - Cephalic V. - passes up from Dorsal venous arch along lateral (radial) side of forearm. At elbow it connects with Median cubital V. It continues up arm cutaneously, goes deep below Deltoideus. Near clavicle it dumps into Axillary V.

95 CROSS-SECTION OF THE ARM

96 CROSS-SECTION OF THE FOREARM

Note: Pronator teres is shown near its insertion on the radius, but originates on the medial epicondyle and passes diagonally across the flexor side of the forearm.

97 OSTEOLOGY OF THE PELVIC GIRDLE AND LOWER EXTREMITY

PELVIC BONES (=Os coxa) consisting of 3 fused bones: Ilium, Ischium, & Pubis

Acetabulum - articulates with head of femur Obturator foramen - covered by fascia, origin of Obturator internus and externus Pubic Symphysis - median joint of two pelvic bones

ILIUM

Auricular Surface - articulates with sacrum Iliac Crest - Iliac Fossa - origin of Iliacus Anterior Superior Iliac Spine - origin of Sartorius Anterior Inferior Iliac Spine - origin of Rectus femoris Greater Sciatic Notch - Piriformis, Sciatic N., etc. pass through Gluteal Lines - margins of origins of gluteal Mm.

ISCHIUM

Body Ramus Ischial Spine - attachment of Sacrospinous Ligament Ischial Tuberosity - origin of hamstrings Lesser Sciatic Notch - Obturator internus passes through

PUBIS

Body Superior and Inferior Rami Symphyseal Surface - articulates with opposite pubis

FEMUR

Head - articulates with pelvic bone Neck Shaft Greater Trochanter - insertion of lateral rotators and gluteal Mm. Lesser Trochanter - insertion of Iliopsoas Intertrochanteric line Intertrochanteric crest Gluteal Tuberosity - insertion of deep part of Gluteus maximus Linea Aspera - insertion of adductors, origin of vasti, Biceps femoris short head Medial & Lateral Supracondylar Lines Medial & Lateral Epicondyles - attachment for collateral ligaments Adductor Tubercle - insertion of part of Adductor magnus Medial & Lateral Condyles - articulate with tibia Patellar Surface - articulates with patella Intercondylar Notch (or Fossa) - space for cruciate ligaments

98 TIBIA

Medial and Lateral Condyles - articulate with femur Intercondyloid Eminence (or Tubercles) - attachment for cruciate ligaments Tibial Tuberosity - insertion of Ligamentum patellae Popliteal (or Soleal) Line - superior margin of origin of Soleus Anterior Border (or Crest) Superior and Inferior Fibular Articular Facets - articulate with fibula Medial Malleolus - attachment of ligaments and pulley for plantarflexors Inferior Articular Surface - articulates with talus

FIBULA

Head - insertion of Biceps femoris, ligaments Lateral Malleolus - attachment for ligaments and pulley for peroneal Mm.

TARSUS

Talus Calcaneus Calcaneal Tuberosity - heel; insertion of superficial plantarflexors, origin of some plantar Mm. Sustentaculum Tali - pulley for Flexor hallucis longus Navicular Cuboid Cuneiforms (3): First (or Medial) / (or Intermediate) / (or Lateral)

METATARSALS I-V AND PHALANGES

Each metatarsal has: Base (or Proximal end) and Head (or Distal end) Metatarsal V has a Tuberosity Digit I (=Hallux) has: Proximal and Distal Phalanges Digits II-V have: Proximal, Middle, and Distal Phalanges

JOINTS OF LOWER EXTREMITY

Movements of Hip joint

- extension and flexion - aBduction and adduction - medial and lateral rotation

Movements of Knee joint

- flexion and extension - slight medial and lateral rotation of tibia

Movement of Ankle (=Tibiotalar) joint

- dorsiflexion and plantarflexion

Movement of Subtalar and Calcaneotalonavicular joints

- inversion and eversion

99 100 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE ANTERIOR THIGH

Vastus lateralis Linea aspera and Patella and Lig. Extends knee lateral side patellae to tibia (Femoral N.) of femur

Vastus intermedius Anterior and Patella and Lig. Extends knee lateral femur patellae to tibia (Femoral N.)

Vastus medialis Linea aspera and Patella and Lig. Extends knee medial side of patellae to tibia (Femoral N.) femur

Rectus femoris Anterior inferior Patella and Lig. Flexes hip, iliac spine and patellae to tibia extends knee upper margin of (Femoral N.) acetabulum

Sartorius Anterior superior Upper part of Flexes hip, iliac spine medial surface flexes knee of tibia (Femoral N.)

Note: All muscles of the anterior thigh are innervated by the Femoral N.

Note: Tensor fasciae latae may be included in drawings of the muscles of the anterior thigh because of its position, but it should be considered a gluteal muscle.

Note: Articularis genu is a small deep slip of Vastus intermedius that inserts on the synovial capsule of the knee and pulls the capsule up when the knee is extended.

101 102 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE MEDIAL THIGH

Iliopsoas Iliacus - iliac Lesser trochanter Flexes hip fossa of femur (Femoral N.)

Psoas major - (Upper 3 or 4 lumbar vertebrae lumbar Nn.)

Pectineus Superior ramus of Line from lesser Adducts, flexes, pubis trochanter to and laterally linea aspera rotates hip (Femoral N.)

Adductor brevis Anterior surface Linea aspera Adducts hip of inferior ramus (Obturator N.) of pubis

Adductor longus Anterior surface Linea aspera Adducts hip of body of pubis (Obturator N.)

Adductor magnus Inferior ramus of Linea aspera and Adducts hip pubis and ischial medial supra- (Obturator N.) tuberosity condylar line to adductor tubercle

Gracilis Body and inferior Upper part of Adducts hip; ramus of pubis medial surface flexes and near the symphysis of tibia medially rotates knee (Obturator N.)

103 104 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE POSTERIOR THIGH

Semimembranosus Ischial tuberosity Posterior surface Extends hip, of medial condyle flexes knee of tibia (Sciatic N.)

Semitendinosus Ischial tuberosity Upper part of Extends hip, medial surface flexes knee of tibia (Sciatic N.)

Biceps femoris Long head - Head of fibula Extends hip, ischial tuberosity flexes knee (Sciatic N.)

Short head - linea Flexes knee aspera and lateral (Sciatic N.) supracondylar line

Note: All muscles of the posterior thigh are innervated by the tibial division of the Sciatic N., and some books state that Semimembranosus and Semitendinosus are innervated by the Tibial N.

105 106 —————————————————————————————————————————————————————————————————————————————— LATERAL ROTATORS OF THE FEMUR

Piriformis Anterior surface Greater Rotates hip of sacrum - passes trochanter of laterally through greater femur (L5-S2) sciatic foramen

Gemmellus superior Ischial spine Tendon of Rotates hip Obturator internus laterally (N. to Obturator internus)

Obturator internus Internal (=post.) Tendon passes Rotates hip surface of through lesser laterally obturator fascia sciatic foramen to (N. to Obturator medial surface of internus; L5-S2) greater trochanter

Gemmellus inferior Upper part of Tendon of Rotates hip ischial tuberosity Obturator internus laterally (N. to Quadratus femoris)

Obturator externus External (=ant.) Trochanteric Adducts and surface of fossa of femur laterally obturator fascia rotates hip (Obturator N.)

Quadratus femoris Ischial tuberosity Quadrate tubercle Adducts and of femur laterally rotates hip (N. to Quadratus femoris; L4-S1)

Note: Obturator externus can be seen between Gemmellus inferior and Quadratus femoris in the gluteal region. Its origin can be seen in the medial thigh if Adductor longus and brevis and Pectineus are reflected; it is then superior (and deep) to the upper margin of Adductor magnus.

107 108 —————————————————————————————————————————————————————————————————————————————— GLUTEAL MUSCLES

Gluteus minimus Outer surface of Anterior border ABducts and ilium between of greater medially rotates anterior and trochanter with hip inferior gluteal Gluteus medius (Sup. gluteal N.) lines

Gluteus medius Upper part of the Lateral surface ABducts and outer surface of of greater medially rotates ilium trochanter hip (Sup. gluteal N.)

Gluteus maximus Posterior gluteal Posterior femur Extends, adducts, line of ilium and and iliotibial and laterally posterior surface tract rotates hip of sacrum and (Inf. gluteal N.) coccyx

Tensor fasciae Outer surface of Iliotibial tract ABducts and latae ilium behind medially rotates anterior superior hip iliac spine (Sup. gluteal N.)

Note: The main function of Tensor fasciae latae and Gluteus minimus and medius is to brace the hip during walking to keep the pelvis level when the opposite foot is off the ground.

109 110 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE ANTERIOR CRURAL COMPARTMENT - DORSIFLEXORS

Tibialis anterior Upper 2/3 of Tendon to medial Dorsiflexes ankle, lateral tibia surface of inverts foot and interosseus metatarsal I and (Deep peroneal N.) membrane medial cuneiform

Extensor hallucis Middle 1/2 of Tendon to base of Extends hallux, longus fibula distal phalanx of dorsiflexes ankle hallux (Deep peroneal N.)

Extensor digitorum Upper 3/4 of Tendon divides Extends digits longus fibula and into 4 and each II-V, dorsiflexes interosseus inserts on distal ankle membrane phalanges of (Deep peroneal N.) digits II-V

Peroneus tertius Small slip of Base of metatarsal Everts foot extensor digitorum V (Deep peroneal N.) longus

Note: All muscles of the anterior crural compartment are innervated by the Deep peroneal N.

111 112 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE POSTERIOR CRURAL COMPARTMENT - SUPERFICIAL PLANTARFLEXORS

Soleus Upper 1/3 of Calcaneus by Plantarflexes posterior fibula, Tendo calcaneus ankle middle 1/3 of (Tibial N.) posterior tibia

Plantaris Lateral femoral Long tendon to Plantarflexes condyle with medial side of ankle Gastrocnemius posterior (Tibial N.) calcaneus

Popliteus Lateral femoral Posterior tibia Rotates leg condyle above soleal line medially (Tibial N.)

Gastrocnemius Medial and lateral Calcaneus by Plantarflexes heads from medial Tendo calcaneus ankle, flexes knee and lateral (Tibial N.) femoral condyles, respectively

Note: Popliteus does not insert on the foot and so is not a plantarflexor. Its main function is to rotate the tibia medially on the femur to unlock the knee joint and permit it to be flexed.

Note: All muscles of the posterior crural compartment are innervated by the Tibial N.

113 114 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE POSTERIOR CRURAL COMPARTMENT - DEEP PLANTARFLEXORS

Flexor digitorum Middle of Tendon passes Flexes digits longus posterior tibia medial malleolus, II-V, divides into four plantarflexes tendons and each ankle inserts on 3rd (Tibial N.) phalanx of digits II-V

Tibialis posterior Upper 2/3 of Tendon passes Plantarflexes medial fibula, medial malleolus, ankle, inverts interosseus and inserts on the foot membrane, and tuberosity of (Tibial N.) lateral tibia navicular and plantar surface of cuneiforms, etc.

Flexor hallucis Lower 2/3 of Tendon passes Flexes hallux, longus posterior fibula beneath plantarflexes sustentaculum ankle tali, inserts on (Tibial N.) 2nd phalanx of hallux

Note: All muscles of the posterior crural compartment are innervated by the Tibial N.

115 116 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE LATERAL CRURAL COMPARTMENT

Peroneus longus Upper 2/3 of Tendon passes Plantarflexes anterior fibula behind lateral ankle, everts foot malleolus, inserts (Superficial on lateral side of peroneal N.) metatarsal I

Peroneus brevis Lower 2/3 of Tendon passes Plantarflexes anterior fibula behind lateral ankle, everts foot malleolus, inserts (Superficial on base of peroneal N.) metatarsal V

Note: Both muscles in the lateral crural compartment are innervated by the Superficial peroneal N.

117 118 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE DORSUM OF THE FOOT

Extensor digitorum Upper anterior By four tendons to Extends digits brevis surface of the digits I-IV; 1st I-IV calcaneus on base of 1st (Deep peroneal N.) phalanx of digit I; 2nd-4th on lateral sides of tendons of Extensor digitorum longus

Extensor hallucis Upper anterior Tendon to base of Extends hallux brevis surface of the 1st phalanx of (Deep peroneal N.) calcaneus digit I

Note: Both muscles are innervated by the Deep peroneal N. that also innervates the muscles of the anterior crural compartment.

Note: Extensor hallucis brevis is considered to be a part of Extensor digitorum brevis.

119 120 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE SOLE OF THE FOOT - 1ST LAYER

ABductor hallucis Calcaneal tuber Medial side of ABducts hallux base of 1st (Med. plantar N.) phalanx of digit I

Flexor digitorum Calcaneal tuber 2nd phalanx of Flexes digits II-V brevis digits II-V (Med. plantar N.)

ABductor digiti Calcaneal tuber Lateral side of ABducts digit V minimi base of 1st (Lat. plantar N.) phalanx of digit V

—————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE SOLE OF THE FOOT - 2ND LAYER

Quadratus plantae By 2 heads from Tendon of Straightens pull calcaneal tuber Flexor digitorum of Flexor and plantar longus digitorum longus, ligaments flexes digits II-V (Lat. plantar N.)

Lumbricales (4) Sides of tendons With tendons of Flex digits II-V of M. flexor Extensor digitorum at metatarso- digitorum longus longus and into phalangeal joints, medial sides of extend digits II-V bases of the 1st at interphalangeal phalanges of joints digits II-V (Med. and Lat. plantar Nn.)

121 122 —————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE SOLE OF THE FOOT - 3RD LAYER

Flexor hallucis Cuboid, lateral By 2 bellies on Flexes hallux brevis cuneiform, and medial and lateral (Med. plantar N.) ligaments at base sides of base of of metatarsal I 1st phalanx of digit I

Adductor hallucis Two heads: oblique Lateral side of Adducts hallux, head from bases of base of 1st assists in flexing metatarsals II-IV; phalanx of digit I (Lat. plantar N.) transverse head from metatarso- phalangeal joint capsules of digits II-V

Flexor digiti Base of metatarsal Lateral side of Flexes digit V minimi V 1st phalanx of (Lat. plantar N.) digit V

—————————————————————————————————————————————————————————————————————————————— MUSCLES OF THE SOLE OF THE FOOT - 4TH LAYER

Plantar interossei Bases and medial Medial sides of Adduct digits (3) sides of 1st phalanges of III-V toward axis metatarsals III-V digits III-V of digit II (Lat. plantar N.)

Dorsal interossei By two heads from Into bases of 1st ABduct digits (4) the sides of phalanges; II-IV from axis of adjacent on medial side of digit II metatarsals I-V digit II, and on (Lat. plantar N.) lateral sides of digits II-IV

Note: PAD (Plantar ADduct) and DAB (Dorsal ABduct) are words.

123 NERVES OF THE LOWER EXTREMITY

124 NERVES OF THE LOWER EXTREMITY

I - Femoral N. - passes under Inguinal ligament into Femoral Triangle lateral to Femoral A+V. It divides into muscular branches and Saphenous N.

A - Nn. to Vasti - branches of Femoral N. that supply the vasti.

B - Saphenous N. - passes down adductor canal with Femoral A+V. It does not pass through adductor hiatus, but continues with Saphenous A. and becomes cutaneous after passing knee.

II - Obturator N. - passes through obturator foramen, divides into 2 branches found between Adductor longus and magnus.

III - Sciatic N. - arises from sacral plexus, passes between Piriformis and Obturator internus. Then passes down thigh deep to Gluteus maximus and hamstrings. A short distance above knee it divides into Tibial and Common peroneal Nn.

A - Tibial N. - passes down popliteal fossa and posterior crural compartment with Popliteal A+V and Posterior tibial A+V. Behind knee it sends off Medial sural cutaneous N. Behind medial malleolus it divides into Medial and Lateral plantar Nn.

1 - Medial sural cutaneous N. - descends leg between heads of Gastrocnemius. May join with Lateral sural cutaneous N. to form Sural N.

2 - Medial plantar N. - passes anteriorly toward base of metatarsal I with Medial plantar A.

3 - Lateral plantar N. - passes anteriorly toward base of metatarsal V with Lateral plantar A.

B - Common peroneal N. - passes through popliteal fossa with Biceps femoris tendon, sends off Lateral sural cutaneous N., curls around head of fibula, and splits into Superficial and Deep peroneal Nn.

1 - Lateral sural cutaneous N. - passes down lateral side of leg.

2 - Deep peroneal N. - passes between tibia and fibula, into and down anterior crural compartment with Anterior tibial A+V. Terminal branches continue onto dorsum of foot.

3 - Superficial peroneal N. - passes down lateral crural compartment between Peroneus longus and brevis and Extensor digitorum longus. Terminal branches continue onto dorsum of foot as acutaneous nerve.

125 NERVES AND ARTERIES IN THE GLUTEAL REGION

126 NERVES AND ARTERIES IN THE GLUTEAL REGION

NERVES

I - Branches of sacral plexus in gluteal region

A - Superior gluteal N. - found with Superior gluteal A+V superior to Piriformis, then passes laterally with deep branches of Superior gluteal A+V between Gluteus minimus and medius.

B - Inferior gluteal N. - found with Inferior gluteal A+V between Piriformis and Obturator internus, and medial to Sciatic N.

C - Pudendal N. - found with Inferior pudendal A+V between Piriformis and Obturator internus, medial to Superior gluteal NAV, and passing deep to perineal region.

D - Sciatic N. - arises from sacral plexus, passes between Piriformis and Obturator internus. Then passes down thigh deep to Gluteus maximus and hamstrings.

ARTERIES

I - Branches of Internal Iliac A. in gluteal region

A - Superior gluteal A. - found with Superior gluteal N. superior to Piriformis. Deep branches pass laterally between Gluteus minimus and medius, and superficial branches pass laterally between Gluteus medius and maximus.

B - Inferior gluteal A. - found with Inferior gluteal N. between Piriformis and Obturator internus and medial to Sciatic N.

C - Internal pudendal A. - found with Pudendal N. between Piriformis and Obturator internus and medial to Sciatic N. It goes deep to inguinal region.

127 ARTERIES OF THE LOWER EXTREMITY

128 ARTERIES OF THE LOWER EXTREMITY

Ia - Femoral A. - continuation of External iliac A. after passing under Inguinal ligament. Passes down femoral triangle, adductor canal, through adductor hiatus, and becomes Popliteal A.

A - Profunda femoris A. - branches off in Femoral triangle, goes deep toward femur, and passes down thigh deep alongside femur.

1 - Medial femoral circumflex A. - branches off about 2 cm from origin of Profunda femoris A., passes medially between Iliopsoas and Pectineus, around back of femur, and anastomoses with Lateral femoral circumflex A.

2 - Lateral femoral circumflex A. - branches off about 2 cm from origin of Profunda femoris A., splits into three branches; one branch passes laterally around femur, and anastomoses with Medial femoral circumflex A.

Ib - Popliteal A. - continuation of Femoral A. on posterior thigh. It passes through popliteal fossa, and divides into Anterior and Posterior tibial Aa. shortly below knee.

A - Superior medial genicular A. ┐ Pass around knee from posterior to Superior lateral genicular A. ├ anterior and anastomose together. Inferior medial genicular A. │ Superiors branch off above heads of Inferior lateral genicular A. ┘ Gastrocnemius, inferiors below.

Bi - Anterior tibial A. - passes between tibia and fibula into and down anterior crural compartment on interosseus membrane. As it crosses ankle it becomes Dorsalis pedis A.

Bii - Dorsalis Pedis A. - continuation of Anterior tibial A. Passes under extensor retinacula toward base of metatarsal I.

1 - Arcuate A. - runs laterally along bases of metatarsals.

a - Dorsal metatarsal Aa. - four; each passes distally between metatarsals and divides into dorsal digital Aa. i - Dorsal digital Aa. - pass distally along digits.

C - Posterior tibial A. - passes down posterior crural compartment deep to Soleus, passes behind medial malleolus, and splits into Medial and Lateral plantar Aa.

1 - Peroneal A. - branches off Posterior tibial A. about 6 cm below knee, and passes deep along fibula.

2 - Medial plantar A. - passes anteriorly toward base of metatarsal I with Medial plantar N.

3 - Lateral plantar A. - passes anteriorly toward base of metatarsal V with Lateral plantar N.

129 CUTANEOUS VEINS OF THE LOWER EXTREMITY

I - Great saphenous V. - drains Dorsal venous arch and runs in front of medial malleolus, up medial side of lower extremity, and ends in Femoral V. in femoral triangle.

A - Dorsal venous arch - runs across top of foot at base of toes, drains at each end into Great and Small saphenous Vv. respectively.

II - Small saphenous V. - drains Dorsal venous arch and runs behind lateral malleolus, up back of leg, and ends in Popliteal V.

130 CROSS-SECTION OF THE THIGH

131 CROSS-SECTION OF THE LEG

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