The Upper Extremity

The Upper Extremity

Arm Muscles, Axilla, Brachial Plexus Bones of Upper Extremity

ƒ Appendicular Skeleton ƒ Pectoral Girdle = scapula,clavicle ƒ Upperlimb

z Arm: humerus

z Forearm: radius, ulna • Interosseus membrane

z Hand: carpals, metacarpals, phalanges ƒ Review Bones + Landmarks studied in Lab!! Joints of Upper Extremity ƒ Sternoclavicular

z Synovial-saddle

z Diarthrosis ƒ Acromioclavicular

z Synovial-plane

z Diarthrosis ƒ Glenohumeral joint

z Synovial-ball&socket

z Diarthrosis

z Many ligaments

z Muscle reinforcement

z Great Mobility Joints of the Upper Extremity

ƒ Elbow Joint

z Synovial – hinge

z Diarthrosis ƒ Articulations

z Humerus & Ulna

z Humerus & Radius ƒ Many Ligaments Joints of Upper Extremity

ƒ Proximal Radioulnar joint

z Synovial - pivot

z Diarthrosis ƒ Distal Radioulnar joint

z Synovial – pivot

z Diarthrosis ƒ Allows pronation and supination of forearm Joints of the ƒ Radiocarpal joint z Synovial-condyloid Upper Extremity z Distal radius with proximal row of carpals ƒ Intercarpal joints z Synovial-plane ƒ Carpal-metacarpal (2-5) z Synovial-plane ƒ Trapezium-metacarpal 1 z Synovial-saddle ƒ Metacarpal-phalangeal z Synovial-condyloid ƒ Interphalangeal z Synovial-hinge ƒ ALL DIARTHROSES Review of Naming

What do the following names TELL you about the muscle?

ƒ Naming

z Flexor carpi ulnaris

z Flexor digitorum superficialis

z Flexor pollicis longus

z Pronator quadratus

z Extensor carpi radialis brevis

Refer to tables in chapter 11 of text for muscle O + I (Table 11.8-11.13) Know at least 1 action of every muscle Muscles ƒ If ORIGIN on scapula = Move Arm z Subscapularis Rotator z Supraspinatus of Scapula Cuff z Infraspinatus

z Teres Minor

z Teres Major

z Latissimus Dorsi (partial O on scap)

z Coracobrachialis ƒ If INSERTION on scapula = Move scapula

z Rhomboids

z Trapezius

z Pectoralis Minor

z Serratus Ventralis

z Levator Scapulae pg 283 Use location of Insertion to determine movement!! Innervation of Scapula Muscles ƒ Origin on Scapula:

z Latissimus dorsi = Thoracodorsal nerve

z Subscapularis, Teres Major = Subscapular nerves

z Supraspinatus, Infraspinatus = Suprascapular nerves

z Teres Minor = Axillary nerve ƒ Insertion on Scapula

z Levator Scapular, Rhomboids = Dorsal Scapular nerve

z Pectoralis Minor = Pectoral n.

z Serratus Ventralis = Long Thoracic n.

z Trapezius = Accessory n.

Refer to tables in chapter 11 of text for muscle O + I Know at least 1 action of every muscle Muscles of Arm: Cross elbow, Move forearm ƒ 2 Compartments

z Anterior: Flexors of forearm

z Posterior: Extensors of forearm ƒ Anterior Compartment

z Biceps brachii = MC nerve

z Brachialis = MC nerve

z Brachioradialis = Radial nerve ƒ Coracobrachialis = MC nerve

z O = coracoid process of scapula

z I = medial side humeral shaft

z A = flex, adduct arm ƒ Posterior Compartment

z Triceps brachii = Radial nerve

z Anconeus = Radial nerve

MC = musculocutaneous nerve Muscles of forearm: Cross wrist + finger joints, moves hand

ƒ Cross Wrist = flex, extend, abduct, adduct hand ƒ Cross Fingers = flex, extend fingers ƒ Most muscles fleshy proximally, long tendons distally ƒ Flexor + Extensor Retinacula

z wristbands keep tendons from bowing

z thick, deep fascia ƒ Anterior Flexor Compartment (Superficial + Deep layers)

z Most flexors have common tendon on medial epicondyle

z Contains 2 pronators

z Innervated by *Median, Ulna nerves ƒ Posterior Extensor Compartment (Superficial + Deep layers)

z Innervated by Radial nerve (or branches of) Innervation of Anterior Compartment-Forearm Muscles Muscle Nerve ƒ Superficial Muscles

z Flexor digitorum superficialis Median

z Flexor carpi radialis Median

z Pronator teres Median

z Palmaris longus Median

z Flexor carpi ulnaris Ulnar ƒ Deep Muscles

z Pronator quadratus Median

z Flexor pollicis longus Median

z Flexor digitorum profundus Ulnar (med 1/2) Median (lat 1/2) Anterior Compartment Forearm pg 302 Medial Epicondyle

Brachioradialis Pronator Teres

Flexor Carpi Radialis

Flexor Carpi Ulnaris Flexor Retinaculum

Flexor Digitorum Superficialis Anterior View is deep to other flexors Innervation of Posterior Compartment-Forearm Muscles Muscle Nerve ƒ Superficial

z Extensor carpi radialis longus Radial

z Extensor digitorum Radial

z Extensor carpi ulnaris Radial ƒ Deep

z Supinator Radial

z Abductor pollicis longus Radial

z Extensor pollicis longus + brevis Radial

z Extensor indicus Radial Posterior Compartment of Forearm

Lateral Epicondyle

Brachioradialis Extensor digitorum Extensor carpi ulnaris Ext Carpi Radialis Longus

Posterior View Intrinsic Muscles of Hand Muscle Nerve ƒ Pinky (little finger)

z All digiti minimi Ulnar (Flexor, Abductor, Opponens) ƒ Thumb

z Abductor pollicis brevis Median

z Flexor pollicis brevis Median

z Opponens pollicis Median

z Adductor pollicis Ulnar ƒ Other Intrinsic Muscles

z Palmar + Dorsal Interossei Ulnar

z Lumbricals Median, Ulnar Intrinsic Muscles of Hand pg 297

Palmar Dorsal Lumbricals Interossei Interossei 3rd ABduction ADDuction 2nd

4th 1st

Interossei help the lumbricals to extend IP joints and flex MC-P joints Blood Supply: Veins

SUPERFICIAL •Cephalic (arm-forearm) •Basilic (arm-forearm) DEEP •Subclavian (neck) •Axillary (axilla) •Median Cubital (elbow) •Median Vein •Brachial (arm-elbow)

•SF. Palmar Venous Arch •Digital •Radial (forearm) •Ulnar (forearm) •Deep Palmous Venous arch

pg 547 Blood Supply: Arteries ƒ Subclavian (neck) ƒ Axillary (armpit)

z Subscapular ƒ Brachial (arm)

z Deep brachial ƒ Radial (forearm) ƒ Ulnar (forearm)

z Common Interosseous ƒ Superficial & Deep Palmar arches

z Digital Pg 536 Axilla = Armpit ƒ Region between arm and chest ƒ Boundaries

z Ventral - pectoral muscles

z Dorsal = latissimus dorsi, teres major subscapularis

z Medial = serratus ventralis

z Lateral = bicipital groove of humerus ƒ Contents

z Axillary lymph nodes, Axillary vessels Brachial Plexus Surface Anatomy of Upper Limb ƒ Biceps + Triceps brachii ƒ Olecrenon Process ƒ Medial Epicondyle ƒ Cubital Fossa

z Anterior surface elbow

z Contents • Median Cubital Vein • Brachial Artery •Median Nerve

z Boundaries • Medial= Pronator teres • Lateral= Brachioradialis • Superior= Line between epicondyles pg 748 Surface Anatomy ƒ Carpal Tunnel z Carpals concave anteriorly of Upper Limb z Carpal ligament covers it

z Contains: long tendons, Median nerve

z Inflammation of tendons = compression of Median nerve ƒ Anatomical Snuffbox

z Lateral = E. pollicis brevis

z Medial = E. pollicis longus

z Floor = scaphoid, styloid of radius

z Contains Radial Artery pg 749 (pulse) Brachial Plexus

ƒ Network of nerves; part in neck, part in axilla ƒ Muscles of upper limb receive innervation from nerves of the brachial plexus ƒ Formed from Ventral Rami of Inferior 4 Cervical Nerves

(C5-8) and T1 Where Ventral Rami Come From

Dorsal Root Dorsal Ramus of spinal nerve

Ventral Ramus of spinal nerve

spinal nerve

Pg 381 Ventral Root Parts of Brachial Plexus

ƒ Really Tired? Drink Coffee Buddy!

ƒ R = ROOTS (ventral rami) ƒ T = TRUNKS ƒ D = DIVISIONS ƒ C = CORDS ƒ B = BRANCHES Roots join to form Trunks! (in neck)

ƒ Ventral Rami Trunks

ƒ C5 Upper Trunk ƒ C6 ƒ C7 Middle Trunk ƒ C8 ƒ T1 Lower Trunk Trunks Split to form Divisions! (in neck) ƒ Trunks Divisions

ƒ Upper Anterior Posterior

ƒ Middle Anterior Posterior

ƒ Lower Anterior Posterior Divisions Join to form Cords! (in axilla)

Trunks Divisions Cords U A LATERAL CORD P M A P MEDIAL CORD

L A P POSTERIOR CORD Cords Give off Branches!! (in axilla)

ƒ Lateral Musculocutaneous

Median

ƒ Medial Ulnar

ƒ Posterior Radial Axillary (thoracodorsal) (subscapular) PUT IT ALL TOGETHER…...

pg 416 Learn Figure 14.11c in textbook! Innervation by Posterior Cord ƒ Radial Nerve (largest branch)

z Course: Through arm, around humerus, around lateral epicondyle, then divides

z Innervates: all posterior muscles of arm and forearm • Triceps brachii, anconeus, supinator, brachioradialis

z Divides in forearm: • Superficial = skin of arm and dorsolateral surface of hand • Deep = extensor muscles of forearm (eg E. carpi radialis L + B)

z Damage to Radial Nerve = wristdrop • Inability to extend the hand, st inability to fully extend forearm Innervation by Posterior Cord (continued)

ƒ Axillary Nerve (runs w/ caudal humeral circumflex a.)

z Innervates: • Deltoid and Teres minor (motor inn) • Capsule of shoulder, skin of shoulder (sensory inn)

ƒ Subscapular Nerve {branches of C5 + C6 rami}

z Innervates: Subscapularis, Teres major

ƒ Thoracodorsal Nerve (runs w/thoracodorsal a+v)

z Innervates: Latissimus dorsi Innervation by Lateral Cord ƒ Musculocutaneous

z Course: branches to arm, distal to elbow becomes cutaneous for lateral forearm skin

z Innervates • Biceps brachii, brachialis, coracobrachialis (motor inn) • Skin distal to elbow (sensory)

ƒ Suprascapular (runs w/suprascapular a+v) {C5, C6}

z Innervates: Supraspinatus, Infraspinatus Innervation by both Lateral and Medial Cords ƒ Median

z Course: middle of brachial plexus, does not branch in arm, distal to elbow provides many branches to most forearm flexors, passes through carpal tunnel to hand to lateral palmar intrinsics

z Innervates: most muscles of anterior forearm (motor inn) • (eg) most flexors, some intrinsics (thumb)

z Innervates: skin of lateral 2/3 hand on palm side, dorsum of fingers 2+3 (sensory inn)

z Nerve Damage = “Ape” Hand • Inability to Oppose Thumb Innervation by Medial Cord ƒ Ulnar

z Course: runs along medial side of arm, behind medial epicondyle, superficial to carpal tunnel into hand, branches to supply intrinsics and skin

z Innervates: • FCU and part of FDP, most intrinsics (motor inn) • Skin of medial 2/3 of hand A+P (sensory inn)

z Nerve Damage: Clawhand • Inability to extend fingers at interphalangeal joints, results in permanent flexion = claw Cutaneous Innervation to the Hand Median Nerve Ulnar Nerve Brachial Artery Musculocutaneous Nerve UlnarArtery

Where’s Radial Nerve?

Radial Artery

Median Nerve Ulnar Nerve