Unit 10: The Neck A Flashcards
What are the two uniquely named cervical vertebrae?
Atlas (first cervical vertebrae)
Axis (Second cervical vertebrae)
What three features distinguish cervical vertebrae from other vertebrae?
Trigingular vertebral foramen
Bifid spinous process
Transverse foramina
What are the unique features of atlas (c1)?
Articulates with the occiput of the head and axis
No vertebrael body and no spinous process
Lateral masses which are connected by an anterior and posterior arch
Each lateral mass has a superior and an inferior articular facet.
What are the features of the anterior arch of the atlas?
Has a facet for articulation with the dens of the axis.
What is the role of the transverse ligament of the atlas?
Secures the attachment of the dens (c2) to the articular facet in the anterior arch of c1.
What are the features of the posterior arch of the atlas?
Has a groove for the vertebral artery and C1 spinal nerve.
What are the identifiable features of the axis (c2)?
Dens or odnotoid process
Superior articular facets
What is the lateral atlanto-axial joints?
Are two in total
Made from the joining of the superior articular facets of C2 and the inferior articular facets on the lateral mass of c1
What makes up the medial atlanto-axial joint and what is its function?
The dens on C2 into the articular facet in the anterior arch of the atlas.
Allows for rotation of the head independently of the torso
What features that other cervical vertebrae have does C1 lack?
Vertebral body
Vertebral arch (hence no spinous process)
What joints join vertebral bodies throughout the vertebral column?
Intervertebral discs - made of fibrocartilage
Known as a symphysis (type of cartilaginous joint)
Vertebral arch - synovial joint type between the superior and inferior articular processes of adjacent vertebrae
What classification of joint is the lateral atlanto-axial joint?
Plane type synovial joint
What classification of joint is the medial atlanto-axial joint?
Pivot type synovial joint
What is the atlanto-occipital joint?
What is its function?
Occur between the superior facets of the lateral massess of the atlas and the occipital condyles at the base of the cranium
Permit flexion at the head - e.g nodding
What classification of joint is the atlanto-occipital joint?
Condyloid type synovial joint
What ligaments are found throughout the entire vertebral column?
Posterior longitudinal
Anterior longitudinal
Ligamentum flavum
Interspinous ligament
Identify the ligaments shown in the image
Red and purple - anterior and posterior longitudinal ligament
Blue - ligamentum flavum
Green - interspinal
Yellow - nuchal ligament in cervical, continuous with the supraspinous through out the rest of the spinal cors
What ligaments are unique to the cervical spinal section of the spinal cord?
Transverse ligament of atlas
Nuchal ligament
What is the function of the nuchal ligament?
Continuous with the surpraspinous ligament
Attaches with the tips of spinous process of C1 to c7
Provides proximal attachment for the rhomboid and trapexius
Limits forward flection of the head and the cervical spine
What is the function of the transverse foramina in the cervical vertebrae?
Passageway for the vertebral artery, vein and sympathetic nerves
What structures pass out of the intervertebral foramen?
Spinal nerves
What are the anomalous anatomical relationships of C7 compared to other cervical vertebrae?
Has a set of spinal nerves originating above and below the the transverse formina (in the intervertebral foramina)
Vertebral artery does not pass through the transverse foramina, rather it passes anterior to it
Why is C7 easy to identify grossly?
Large non bifid spinous process can be palpated on the posterior aspect of the neck
How many spinal nerves are associated with the cervical vertebrae?
8
Originate superior to vertebrae
C7 - one superior and inferior to vertebrae.
What is jefferson fracture of the atlas?
Vertical fall onto an extend neck e,g diving into a shallow pool
Compress the lateral masses of atlas - fracture the anterior and posterior arches
If excessive force can also rapture the transverse ligament of he atlas
Unlikley to damage spinal cord at C1 level due to large foramen but damage may occur later down
What is the clincal significance of a hyperextension/whiplash injury?
Damage to the anterior longitudinal ligament of the spine - acutely painful
Fracutes to C vertebrae are suddenly compressed - little change of spinal cord damage due to large foramina
Anterior dislocation at C2 - spinal cord injury causing death or quadriplegia
dislocation at the C6 and C7 level
What is hangman’s fracture?
Fracute of pars interarticularis (bony column joining superior and inferior articular facets of the axis)
Occurs due to high velocity hyperextension and distraction of the head
Often lethal as force or fracture fragments damage the spinal cord
Deep unconsciousness, respiratory failure and cardiac failure
Why is fracture of the dens important clinically?
Unstable and high risk of avascular necrosis
Distal segment isolated from blood supply
Small risk of spinal cord involvement.
What are the borders of the anterior triangle of the neck>
THe inferior border of the mandible
The midline from the sternum to the mandible
The anterior border of the sternocladomastoid
What forms the boundaries of the posterior triangle of the neck?
The posterior boundary of the sternocleidomastoid
The middle 1/3 of the clavicle
The descending part of the trapezius
What groups of muscles make up the anterior triangle of the neck?
The suprahyoid muscles
The infrhyoid muscles (strap muscles)
What are the two division of the infrahyoid muscles?
The superficial and the deep infrahydoid muscles
What makes up the superficial infrahyoid muscles?
Sternohyoid muscles
Superior belly of omohyoid muscle
What is unique about the structure of the oohyoid muscle?
Superior belly runs superior to the clavicle
Inferior belly runs posterior to the clavice
Are connected by a fascial slingover a ligament intersection to the clavicle
What muscles are part of the deep infrahyoid muscles?
Sternothyroid muscle
Thyrohyoid muscle
What innervates the infrahyoid muscles?
Ansa cervicalis (unification of anterior rami of C1,2,3) - loop of muscles close internal jugular vein
Exception - thyohyoid innervated by anterior rami of C1 carried by the hypoglossal nerve
What is the main action of the inferohyoid muscles?
Depress the hyoid bone
What are the additional function of the sternothyroid muscle?
As an infrahyoid will depress the hyoid
Also depress the thyroid cartilage/larynx
What are the additional function of the thyrodhyoid muscle?
As an infrahyoid will depress the hyoid
Will also elevate the thyroid cartilage
Describe the realtionship between the posterior and anterior belly of the digastric muscle?
Connected by a tendonous intersection that links to the hyoid bone by a ligament sling
What is the carotid bifurcation?
Occurs at vertebral level C3 to C4
Where the common carotid splits into the external and internal carotid artery