Neck

Neck

1. Anatomy

   • Posterior Cervical Triangle
     • Bounded by SCM, Trapezius, and clavicle
   • Anterior Cervical Triangle
     • Boundaries: SCM, Midline, Mandible
     • 4 Sub triangles
       • Submental
         • Boundaries: midline, hyoid, anterior digastric
         • Contents: submental lymph nodes, ant jug vein origin
       • Carotid
         • Boundaries: posterior digastric, superior omohyoid, SCM
         • Contents: common carotid a, internal carotid a, external carotid a with its 5 branches, int jug vein, CN X, CN XI, CNXII, ansa cervicalis, transverse cervical nerve from cervical plexus, deep cervical lymph nodes
       • Submandibular/Digastric
         • Boundaries: mandible, ant and post digastric
         • Contents: submandibular gland, submandibular lymph nodes, hypoglossal nerve, mylohyoid nerve, facial artery adn vein
       • Muscular
         • Boundaries: neck midline, SCM, superior omohyoid, hyoid bone
         • Contents: infrahyoid muscles, thyroid and parathyroid glands, larynx, trachea, pharynx, esophagus

2. Landmarks

   • SCM
     • Innervated bY CN XI
     • Actions
       • Bilateral Contraction
         • of posterior fibers: Extension at atlanto-occiptal jt
         • of ant fibers: Flexion at cervical vert
       • Unilateral contraction
         • Ipsilat flex of neck
         • Contralateral rotation of head
     • Clinical conditions
       • Torticollis
         • Neck twisted in position typical of unilateral SCM. caused by trauma during birth or congenital
       • JVD
         • Ext jug veins are distended. Not normal. Signals HTN or R sight Hrt failure
     • Vascular relations
       • Ant jug vein medial to SCM then deep to empty to ext jug/subclavian
       • Ext Jug is superificial
       • Int jug is deep
   • Larynx
     • Thryoid cartilage: Adam's apple. Upper border at C4. Carotid pulse papated below
     • Cricoid cartilage: Inferior to thyroid cart
   • Trachea
     • At C6..inferior to cricoid cartilage. Isthmus anterior to 2nd/3rd tracheal ring
       • **C6 also marks pharynx to esophagus transition. At Middle cervical ganglion
   • Hyoid bone
     • C3. Body, 2 greater horn, 2 lesser horns.
     • Stylohyoid ligament attaches lesser horns and suspends hyoid from styloid process of temporal bone. No direct bony connection to other bones
     • Hyoid fx: freq fx-ed in hanging, strangulation, trauma.
     • Attachment for lots of muscles. Divides neck to suprahyoid and infrahoid