Bones and Joints of the Neck Flashcards
What is the general shape of the neck?
Cylinder
What does the neck link together?
Head above
Thorax below
What parts of the body does the neck communicate with?
Back
Upper limb
How does the neck communicate with the upper limb?
Brachial plexus
Subclavian artery
What are the three Vs of the neck?
Vertebral column
Visceral column
Vascular column
What is the vertebral column?
Large mass of muscle around vertebrae
In gutter between transverse and spinous processes
What is the muscle group called in the vertebral column?
Post-vertebral muscles
What is the function of the post-vertebral muscles?
Maintain position of head
What are the superficial muscles of the neck?
Sternoclydomastoid
Trapezius
What are the attachments of the three scalene muscles?
Transverse process
Top 2 ribs
What is the function of the scalene muscles?
Accessory muscles of respiration > lift ribs
Compared to the post-vertebral muscles, how do the pre-vertebral muscles differ in size and number?
Smaller
Fewer
What is in the visceral cylinder?
Trachea
Oesophagus
Thyroid gland
Which nerve is the visceral cylinder associated with?
Recurrent laryngeal nerve
What is the name of the fascia around the sternoclydomastoid and trapezius?
Investing layer
What structure is formed when the fascia around the trapezius fuses to the spinous process?
Nuchal ligament
What is the fascia surrounding the thyroid called?
Pre-tracheal layer
Where is the vascular cylinder located?
Laterally on either side of visceral cylinder
What is in the vascular cylinder?
Common carotid artery
Internal jugular vein
Vagus nerve behind
Is the fascia around the internal jugular vein thinner or thicker than that around the common carotid artery?
Thinner, because veins stretch with increases in blood volume
Is the internal jugular vein inside or outside the carotid sheath?
Outside
What fascia surrounds the pre-vertebral muscles?
Pre-vertebral layer
What is created between the various fascia of the neck?
Vertical potential spaces
What can track along the potential spaces between the fascia of the neck?
Infection
What are the five regions of the neck?
Posterior 1. Back of neck/vertebral region 2. Posterior triangle 3. Sternomastoid region Anterior 4. Anterior triangle 5. Root of neck
What makes up the vertebral region of the neck?
Vertebrae
Post-vertebral muscles
What are the borders of the posterior triangle of the neck?
Apex = mastoid process
Posterior border = trapezius
Anterior border = sternoclydomastoid
Base = clavicle
What divides the anterior and posterior triangles of the neck?
Sternomastoid region
What is deep to the sternoclydomastoid?
Common carotid artery
Internal jugular vein
Lacerations to muscle can damage vessels
Which nerve comes out of the posterior border of the sternoclydomastoid muscle to innervate the trapezius?
CN XI = accessory nerve
Which area of the neck communicates with the thorax?
- Root of neck
What passes through the root of the neck?
Major vessels pass up to head/down to upper limb
How many vertebrae make up the cervical spine?
7
Why is the trachea surrounded by a series of incomplete rings of cartilage?
To maintain lumen
What is the Adam’s apple?
Angle of thyroid cartilage
What does the hyoid bone provide attachments for?
Supra- and infra-hyoid muscles
What is the function of thee supra- and infra-hyoid muscles?
Muscles of floor of mouth
Muscles continuing to sternum
What is the shape of the a neonate’s spine?
C shaped
Where are the primary curves maintained in the spine?
Thoracic
Sacral
When does the secondary lordosis in the cervical spine start to develop?
At 6 months, when baby starts to be able to support head
When does the cervical spine start to deteriorate and why?
In older age because of degenerative processes
What is the function of post-vertebral muscles?
Resist gravity
Extend head on neck
Extend cervical spine
Help maintain cervical lordosis
Where is the centre of gravity of the head?
Pituitary fossa
Where is the axis of rotation of the head?
Occipital condyles
How do degenerative changes in the post-vertebral muscles contribute to a change in posture?
Degenerative change > loss of tone
At what angle are the pedicels to the body of the cervical vertebra?
45 degrees
Compared to vertebrae in other areas of the spine, what is the size of the cervical vertebral body?
Quite small
What is the lip projecting upwards on the lateral margins of the body of vertebrae C3 to C6?
Uncinate process
What is the function of the uncinate process?
Encapsulates intervertebral discs to some extent
Keeps range of cervical spine primarily in sagittal plane
Partly aids in flexion and extension
What is the association between uncinate processes and degeneration of the cervical spine?
Irritates associated structures
What is the shape and size of the vertebral foramen of the cervical vertebrae?
Large
Triangular
What is the foramen in the transverse process of the cervical vertebra called?
Transverse foramen
What runs in the transverse foramina of C6 to C1?
Vertebral artery
What does the transverse process of the cervical vertebrae terminate in?
Anterior tubercle
Posterior tubercle
Intertubercular bar
What do the anterior and posterior tubercles, and intertubercular bar make together?
Costal element of cervical vertebra
What part of the rib does the anterior tubercle correspond to?
Head of rib
What part of the rib does the intertubercular bar correspond to?
Neck of rib
What part of the rib does the posterior tubercle correspond to?
Tubercle of rib
In what direction do the intervertebral foramina exit?
Obliquely rather than laterally
What attaches to the spinous processes of the cervical vertebrae?
Many post-vertebral muscles
Ligaments
How is the surface area of the spinous processes increased?
Tip split = bifid
Which cervical vertebra doesn’t have a bifid spinous process?
C7
What is the name of C7’s very long spinous process?
Vertebra prominens
Why are the transverse foramina of C7 small?
Because vertebral artery enters at C6
In some variations, where can the vertebral artery enter they spine?
C5 or even C4
What is the carotid tubercle?
Slightly larger anterior tubercle of C6
What can happen at the anterior tubercle?
Can compress carotid artery here > decrease flow to head
What are the scalene muscles?
Scalenus anterior
Scalenus medius
Scalenus posterior
What are the attachments of scalenus anterior?
Anterior tubercle of transverse process
1st rib
What are the attachments of scalenus medius?
Posterior tubercle of transverse process
1st rib
What are the attachments of scalenus posterior?
Posterior tubercle of transverse process
2nd rib
What emerges between scalenus anterior and medius?
Brachial plexus
Subclavian artery
Where does the vertebral column show variations?
At transitional regions
What happens in cranial shift at the cervico-thoracic region?
Cervical rib
Occipitalisation of atlas
What are the features of the cervical rib?
Quite short usually
Rarely see entire bone coming down towards sternum
More commonly fibrous band closes circle
What structures can be endangered by the cervical rib?
Lower trunk of brachial plexus
- Present with ulnar nerve type issues
- Loss of sensation in C8 and T1 dermatomes
Some obstruction of subclavian artery less common
What are the features of occipitalisation of the atlas?
Rarely complete
Usually anterior part fuses with anterior aspect of foramen magnum
What are the atypical cervical vertebrae?
C1 = atlas C2 = axis
What are the features of the atlas?
Essentially ring of bone
Doesn’t have body
Has no intervertebral discs above or below
Instead has space for body of axis
Anterior and posterior arches
Facet for dens
Groove for vertebral artery and C1 dorsal ramus
Saucer-shaped upper surfaces for occipital condyles
Long transverse process
What do the occipital condyles of the atlas allow?
Nodding movements
Does the atlas have a spinous process?
No
Is there any rotation between the atlas and the skull?
No
What are the features of the axis?
Body = dens = odontoid process
Surfaces on dens for articulation with anterior arch of atlas
Strong spinous process
What structures are the uncinate processes modified into in the atlas and axis?
Anterior arch of atlas
Much more anterior facets
Why is the spinous process of C2 so big?
Powerful muscles attach here, including erector spinae
What does erector spinae do to C2?
Anchors C2 > allows head and C1 to rotate
What are important bony landmarks of arteries in the neck?
Carotid artery can be compresses against anterior tubercle of C6 = carotid tubercle
Bifurcation of common carotid artery at C4
Vertebral artery travels in transverse foraminae from C6-C1
Compared to the rest of the spinal cord, what is the size and orientation of the nerve roots in the cervical spine?
Short
Horizontal
Where do the nerve roots pass at C1 and C2?
Behind facet joint
Where do the nerve roots pass at C3-C7?
Between facet joint and transverse foramen
What do osteophytic outgrowths as a result of ageing affect?
Nerve root
Potentially vertebral artery
What are the inferior joints (C2-C7)?
Intervertebral discs
Facet joints
What are the superior (suboccipital) joints?
Atlanto-occipital between head and C1
Atlanto-axial between C1 and C2
What are the features of the intervertebral discs of the cervical spine?
Thick
Central nucleus
Form cervical lordosis
Annulus and nucleus like with lumbar discs
Relatively largest throughout vertebral column
What do the intervertebral discs prevent in the cervical spine?
Forward slip
Rotation
What are the intervertebral discs protected by to some extent?
Uncinate processes
What is the joint between the intervertebral discs and the uncinate process called?
Uncovertebral joint/joint of Luschka
What do the uncinate processes do to the intervertebral discs?
Keep intervertebral discs in position
Limit rotation
Can prolapse occur in the cervical spine, and why?
Yes, because of degeneration
Is prolapse in the cervical or lumbar spine more common, and why?
Lumbar spine due to structure and loading
Why does prolapse in the cervical spine usually occur?
Trauma related to flexion and extension with rotation
What can a prolapse in the cervical spine affect?
Impinge on cord and possibly nerve roots in vertebral canal
What kind of joint are facet joints?
Plane synovial joints
What is the capsule of the facet joints innervated by?
Posterior rami
What is the orientation of the facet joints?
45 degrees between coronal and horizontal planes
What movement do the facet joints allow?
Flexion and extension with rotation
- Orientation means you get lateral flexion with rotation
In what type of injury can you get injury to the facet joints?
Whiplash injury = acceleration of head in antero/posterior direction
What injury happens to the facet joints during hyper-extension in whiplash injury?
Articular surfaces become impacted
Damage to cartilage
Possible fracture of bone
What injury happens to the facet joints during hyper-flexion in whiplash injury?
Stretch of capsule and longitudinal ligaments
What are the atlanto-occipital joints?
2 lateral synovial joints between occipital condyles and upper facets on atlas
What movement do the atlanto-occipital joints allow?
Flexion and extension
About 15-20 degrees
What are the atlanto-axial joints?
3 synovial joints specialised for rotation
Median pivot joint between dens of C2 and anterior arch of atlas
Bursa between transverse ligament and dens
2 lateral facet joints
What movement do the atlanto-axial joints allow?
~50% of rotation of cervical spine
Rotation accompanied by lateral flexion
Where is the transverse ligament in the axis?
Across back of dens
What is the function of the transverse ligament in the axis?
Maintains position of dens against anterior facet
Permits dens 3-4 mm of antero-posterior movement
What can damage to the transverse ligament in the axis result in?
Dens moves back > touches spinal cord
What is the cruciform ligament?
Has vertical and transverse (most important) bands to stabilise dens
What are the alar ligaments?
Go up side of dens
Check range of rotation of atlas around dens
When are the alar ligaments susceptible to injury?
When head flexed and rotated and muscles relaxed
Why shouldn’t people with rheumatoid arthritis have their head manipulated by physiotherapists and chiropracters?
Cruciform and alar ligaments lax > danger that dens will move posteriorly
What are the effects of ageing on the cervical spine?
Water content of nucleus reduces
Range of movement decreases
Cervical discs degenerate earlier than lumbar
Compression of anterior vertebral body > vertebral wedging > reduced lordosis
Osteophytes can develop from uncinate processes and facet surfaces > narrowing of space for cervical spinal cord > irritate nerve roots and possibly occlude vertebral artery
In what direction is the cervical spine particularly susceptible?
Anterio-posterior direction
What is the hangman’s fracture?
Pars fracture of C2
What is Jefferson’s fracture?
Fall onto top of skull > bilateral fracture of anterior arch and pedicle
