2019.Spring Anatomy of the Neck Lecture Lab 2/19(二) PM 1-6 Posterior triangle , 2 Hours + 2 Hours 2/26(二) PM 1-6 Anterior triangle, 1.5 Hours + 3.5 Hours 3/ 5(二) AM 8-12 Deep structure of the neck, 1 Hour + 3 Hours 3/12(二)AM 8-12 Face and scalp, 2 Hours + 2 Hours 3/19(二) PM 1-6 Lect. + Face and scalp lab. 2 Hours 參考書: Anatomy of the Head and Neck, by George H. Paff 電子資源: Grant's Dissection Videos /Acland’s video atlas of human anatomy 賴逸儒 [email protected] Outline The Neck: neurovascular structure/ viscera The triangles of the neck • Posterior triangle • Anterior triangle Fascia and spaces of the neck Triangles of the neck - Sternocleidomastoid muscle (胸鎖乳突肌) - Posterior triangle / anterior triangle 1= SCM 5= Mandible 2= Trapezius 6= Digastric, AB 3= Clavicle 7= Digastric ,PB 4= Omohyoid, PB 8= Hyoid 9= Omohyoid, AB The fascia of the neck • Superficial fascia- between skin and deep fascia • Deep fascia Superficial cervical fascia (continuous, loose subcutaneous tissue) Skin Deep fascia (investing layer) Nerves, vessels, lymph- supply skin Fatty connective tissue (except: eyelid) Scalp <-- --> thorax, upper extremity Platysma: through the superficial Deep fascia: fascia •Investing Platysma (頸闊肌) • Broad, thin muscle Deltoid and pectoris major (skin, Inferior) Mandible, lower face Depressor muscles of mouth • Shaving, grimace • branch of facial nerve (CN. VII) Deep Cervical Fascia (muscular fascia) • Investing • Pretracheal I.F Tr • Prevertebral • Carotid sheath • Retropharyngeal space # posterior Investing Layer of Deep Cervical Fascia • Superficial • Split: Tr - SCM and Trapezius - Manubrium (Suprasternal space) # •Continue posteriorly -Periosteum of spinous process, C7 -Nuchal ligament (#) Suprasternal space jugular arch Pretracheal layers Deep Cervical Fascia Muscular portion Visceral Th Tr portion carotid sheath V Buccopharyngeal fascia limited to anterior part of neck; Thin • Superiorly: hyoid bone • Inferiorly: blends with fibrous pericardium • Posteriorly: buccopharyngeal fascia • Laterally: blends with carotid sheath Prevertebral layer • Tubular sheath for vertebral column and muscles • Cervical sympathetic trunks Roof/Floor of posterior triangle Sympathetic trunk Prevertebral fascia Superiorly: cranial base Inferiorly: • blends w/ endothoracic fascia • fuses w/ ant. longitudinal lig. Prevertebral (Scalene) fascia Laterally: extends as axillary sheaths 10 Carotid sheath from cranial base to root of neck • Common and internal carotid artery • Internal jugular vein • Vagus nerve • Carotid sinus nerve • Sympathetic nerve fibers (periarterial plexus) Carotid sheath and pretracheal fascia communicate freely with the mediastinum inferiorly Retropharyngeal space * skull base --- superior mediastinum (movement of esophagus, larynx during swallowing) Buccopharyngeal fascia alar fascia (post. lamina of pretracheal fascia; cranium to C7) Prevertebral fascia * * Clinical box: Fascia planes and the spread of infection Buccopharyngeal fascia Prevertebral fascia Infra-hyoid muscle Investing layer of deep fascia Esophagus Supra-sternal space Pretracheal layer of deep fascia pericardium Sternocleidomastoid muscle (SCM) Posterior cervical triangle/Anterior cervical triangle •Mastoid process •Superior nuchal line •Lesser supraclavicular fossa Action of SCM • Unilateral contraction • Bilateral contraction: chin lift Sternal head Motor: CN XI, spinal accessory nerve Clavicular head Action of SCM Unilateral contraction: -lateral flexion with rotation - tilts head to same side Trapezius (斜方肌) 1. Muscle of the back 2. Act on pectoral girdle 3. Produce movement of cranium 4. Motor: CN XI, spinal accessory nerve Trapezius test • Shrug the shoulder Trapezius Splenius Posterior triangle (= occipital triangle+ omoclavicular triangle) Boundary -SCM, Trapezius, mid-clavicle Roof: SC PS LS Floor MS AS •Splenius capitis (SC) PS •Levator scapulae (LS) MS AS •Posterior scalene •Middle scalene •Anterior scalene Posterior triangle Content of the posterior triangle - cutaneous nerves of the neck •Branches of cervical plexus: anterior rami, C2,3,4 •Nerve point of neck: midpoint of posterior border of the SCM •Skin of the neck, sup.-lat. thoracic wall, scalp (auricle- occipital protuberance) Greater auricular (C2,C3) -parotid sheath -auricle Transverse cervical (C2, C3): ant. triangle of neck Content of the posterior triangle - External jugular vein Course: • deep to platysma Post. auricular v. Retromandibular v. • Cross the SCM • Parallels greater auricular n. • Ant. jugular v. Pierce investing layer Tribute from scalp and neck: Ext. jugular v. • posterior auricular v., retromandibular v. • Transverse cervical v., suprascapular v. Drain into: subclavian vein 1. Occipital artery at apex 2. Spinal accessory nerve(CN XI) Occipital triangle 3. Cutaneous nerves of cervical plexus Occipital a. Spinal accessory n. Spinal accessory n. Subclavian triangle (Omoclavicular triangle;supraclavicular fossa) • Boundary: - SCM, Omohyhoid (posterior belly), Clavicle Omohyhoid • Content: -Anterior belly - Ext. jugular vein (inferior part) - Intermediate tendon - Subclavian artery (3rd part; deep) -Posterior belly -Brachial plexus (supraclavicular part) rd Transverse cervical a. -Subclavian artery (3 part) -thyrocervical trunk (lateral branches) Remark: branches of subclavian artery B * 2 1 3 Thyrocervical trunk Common carotid a. Transverse cervical a. Suprascapular a. Anterior scalene muscle • 3rd-6th transverse processes Middle st Posterior • 1 rib, scalene tubercle • Lift 1st rib in respiration • Landmark: 1. Subclavian artery, 3 segments 2. Phrenic nerve, on it 3. Brachial plexus: between Anterior ant.-middle scalene ms. Surface anatomy Veins in Posterior cervical triangle 1. External jugular vein -Angle of mandible subclavian vein -Retromandibular vein + posterior auricular vein - across SCM and enter the triangle - Parallels the greater auricular nerve - drain most scalp and side of face 2.Subclavian vein -Join Int. jugular vein brachiocephalic vein -Main draining of the upper limb Subclavian vein Passes anterior to anterior scalene muscle and phrenic nerve; join with IJV Central Venous Catheterization Anatomical consideration Subclavian vein Internal jugular vein Nerves associated with the Posterior triangle 1. CN XI: spinal accessory nerve 2. Brachial plexus (spinal nerves, C5-T1) 3. Cervical plexus Spinal accessory nerve (CN XI, motor) - Superior - middle third SCM - Run on levator scapulae - Deep to Trapezius - Supply SCM and Trapezius Trunk of XI Injury of spinal accessory nerve The cervical and Brachial plexi Each spinal nerve divides into an anterior and posterior ramus. The anterior rami of C1 to C8, and T1 form 2 plexi in the neck. anterior ramus 2.Root of brachial plexus (C5-T1) - Between anterior and middle scalene Phrenic nerve - Cervicoaxillary canal (1st rib, clavicle, sup. border of scapula) axilla 2 3. Roots of cervical plexus Cervical nerves • C1-C4 spinal nerves: supply the neck region • Anterior ramus (C1-4): cervical plexus • Posterior ramus (C1-3): posterior neck and scalp Suboccipital n. (C1) Greater occipital n. (C2) Cervical plexus Anterior rami of , C1,2,3 and most C4, spinal nerve • Series of nerve loops , branches from the loops • Ascending and descending branches (except C1 ) 1. Branches to the skin 2. Nerve to diaphragm (phrenic nerve) 3. Nerves to strap muscles of anterior triangle 4. Nerves to muscles of floors at posterior triangle Cervical plexus: branches to the skin • Appear at nerve point • GA (C2,3): ear lobe • LO (C2): parallel SCM • TC(C2,3): anterior triangle • Supraclavicular nerves (C3,4) : medial, intermediate and lateral Lesser occipital n. Greater auricular n. Transverse cervical n. Supraclavicular n. Great auricular n. Nerve to diaphragm : Phrenic nerve •Chiefly C4 (C3~C5) •Motor, sensory, and sympathetic •Lies on: anterior scalene muscle •Descend obliquely with internal jugular vein Phrenic n. C3 spinal nerve Anterior scalene muscle C5 spinal nerve Phrenic nerve Nerves to strap muscles of anterior triangle: Ansa Cervicalis (hypoglossi) Superior root -C1 and C2 -Briefly join hypoglossal nerve (CN XII) -Pass superficial to the external carotid artery Sup.root Inf.root Inferior root gh: branch to geniohyoid -C2 and C3 th: branch to thyrohyoid St: sternothyroid Sh: sternohyoid Oh: omohyoid Ansa cervicalis : Supply 3 of 4 infrahyoid muscles Hypoglossal nerve Thyrohyoid muscle -Receives C1 fiber -Independently descend from hypoglossal nerve Thyrohyoid muscle Sternohyoid muscle Omohyoid muscle Sternothyoid muscle 40 Motor innervation of the anterolateral neck Superior root of Geniohyoid* Inferior root of Thyrohyoid* Gilroy, Atlas of Anatomy Inferior root Take home message • Muscles boundary of neck region • Vessels and nerves of superficial neck regions.