7. Neck Anatomy Flashcards
What are the features of all 7 cervical vertebrae?
What is unique about C1? C2?
What are the joints and their movements between the head and neck?
All 7: small body, bifid spinous process, transverse foramen (for vertebral artery)
C1: ATLAS - no body, widest cervical vertebra, articulates with occipital condyles
C2: AXIS - dens (odontoid process) is the body of C1 by development, but joins C2
Atlanto-occipital Joint: ONLY flexion-extension
Atlanto-axial Joint: ONLY rotation
What are the 4 cervical ligaments?
- Dura Mater - adherent to bone
- Tectorial Membrane - deep to dura, continues as posterior longitudinal ligament
- Alar “Check” Ligaments - from dens to occipital bone to “check” or restrict rotation
- Cruciate ligaments - hold dens against atlas
Sternocleidomastoid (attachments, actions)
What is Torticollis?
From mastoid down to clavicular and sternal head Flex intervertebral joints, Extend atlanto-occipital joint (due to attachment) Laterally bend neck Contralateral rotation (attaches to back of jaw)
Torticollis: greater muscle tone or fibrosis (shortening) in one SCM - head positioning is flexed, laterally bent, and contralaterally rotated all due to one muscle
Trapezius actions on neck
Extend neck
Laterally bend neck
Contralateral rotation
(elevate, depress, retract shoulder girdle, upward rotation of scapula)
Inferior Oblique in suboccipital region (attachment, action, innervation)
spine of Axis to transverse process of Atlas
Action: same-side rotation
Innervation: dorsal rami of C1
Scalenes: names, actions, structures that pass behind/in front
What is Scalenus Anticus Syndrome? What is Costo-clavicular Syndrome?
3 scalenes: anterior, middle, posterior
Action: lateral bend neck, contralateral rotation, raise rib cage
Behind Ant Scalene: Brachial Plexus, Subclavian Artery
In front of Ant Scalene: Subclavian Vein, Phrenic Nerve
Scalenus Anticus: compression of brachial plexus/subclavian artery in INTERSCALENE TRIANGLE
Costo-Clavicular Syndrome: compression of nerve/vasculature b/w clavicle and first rib - ALL structures pass through here, post-scalenes
What are the infrahyoid “strap” muscles? What are their innervations?
Whiplash-Hyperextension Injury vs. Hyperflexion Injury vs. Compression Injury
Straps: Omohyoid, Sternohyoid, Sternothyroid, Thyrohyoid
Other: Digastric (Mandible to mandible through hyoid), Mylohyoid, Cricothyroid
Whiplash-Hyperextension: soft tissue injury to anterior/lateral structures (discs, ligaments) - can stretch trachea/larynx (hoarse voice), concussion/brain injury
Hyperflexion: posterior structures - vertebrae dislocations/instability (more serious)
Compression: bodies of cervical vertebrae crushed, SC damage in severe cases
Components of Posterior Triangle of Neck and what runs through it
Components of Carotid Triangle and what runs through it
Posterior: SCM, Omohyoid, Trapezius (CN XI through here)
Carotid: Omohyoid, Digastric, SCM (contains carotid sheath)
What are the 3 compartments of the Neck? What is the Danger zone?
- Vertebral: Veterbral bone and muscle surrounded by prevertebral fascia
- Visceral: surrounded by pretracheal fascia (contains thyroid, parathyroids, trachea, esophagus, recurrent laryngeal nerves)
- Carotid Sheaths: contain common carotid, int jugular vein, vagus nerve
Compartments enveloped by deep/investing fascia
Danger Zone: Behind Alar Fascia (between visceral/vertebral compartments) - huge infection/cancer risk of spead to mediastinum
Retropharyngeal Space: b/w alar fascia and pretracheal fascia
Buccopharyngeal Fascia: name for alar fascia above tracheal level
What are the pharyngeal constrictors and what passes between them?
Superior PC - attaches to buccinator
Middle PC - attaches to hyoid
Inferior PC - attaches to thyroid/cricoid cartilages
Above Sup PC: auditory tube, levator palati
B/w Sup/Mid PC - CN IX, Stylopharyngeus m.
B/w Mid/Inf PC - Internal Laryngeal Nerve (through thyroihyoid membrane)
What are the motor nerves and general sensory nerves arising from the cranial plexus?
Motor: Phrenic n. (to diaphragm, over ant scalene), Ansa Cervicalis (to strap muscles), direct muscular branches
Cutaneous: Transverse Cervical (across neck), Supraclavicular n., Greater Auricular (around ear, travels with ext. jugular vein), Lesser Occipital (behind ear)
All cutaneous nerves emerge from posterior triangle
What are the three main neck veins and the connections between them?
- Anterior Jugular
- Internal Jugular
- External Jugular
Retromandibular Vein - Ext to Int
Communicating Branch - Int to Ant
