The Back: Bones, Joints, Ligaments & Muscles Flashcards Preview

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Flashcards in The Back: Bones, Joints, Ligaments & Muscles Deck (64):

What are the different vertebral regions of the spine, and how many vertebrae does each consist of?

(C) Cervical (7)
(T) Thoracic (12)
(L) Lumbar (5)
(S) Sacral (5 fused to 1)
(Co) Coccygeal ( variable 3/4 fused to 1/2


What are the functions of the spinal cord?

+ Locomotion
+ Supports body weight
+ Protects and transmits spinal cord and nerves


What is primary curvature?

+ Kyphosis
+ Concave anteriorly
+ Bases on spinal curvature in utero
+ Remains in thoracic and sacral regions


What is secondary curvature?

+ Lordosis
+ Concave posteriorly
+ Cervical and lumbar regions


What are the different movements allowed throughout the vertebral column, to varying degrees?

+ Extension
+ Flexion
+ Lateral flexion
+ Rotation


What are the features of a typical vertebra?

+ Body
+ Vertebral foramen (canal)
+ Pedicle
+ Transverse process
+ Superior articular facet
+ Inferior articular facet
+ Lamina
+ Spinous process (spine)


What are features of typical cervical vertebrae?

Body: smaller, short AP diameter, longer lateral diameter

Uncinate Processes at lateral edges, synovial articulation with vertebra above

Superior articular facets: flat, facing superiorly and posteriorly

Bifid spine (C7 is not bifid, but prominent)

Vertebral foramen: large, triangular

Foramen transversarium


What movements are assocciated with the cervical region?

1. Flexion is greatest movement
2. Some lateral flexion


What are features of typical thoracic vertebrae?

Body: heart shapes, longer AP diameter, shorter later diameter

Costal demi-facts: upper (articulation with head of own rib) lower (articulation with head below)

Transverse process: long with a facet for articulation with the tubercel of its own rib

Superior articular facets: flat and facing postero-laterally, on the arc of a circle

Spinous process/spine: long and pointing inferiorly, overlapping 2 vertebrae


What movements are associated with the thoracic region?

1. Rotation is the greatest movement


What are features of typical lumbar vertebrae

Body: large for weight bearing, short AP, diameter, longer lateral diameter

Vertebral foramen: small, triangular

Transverse process: length and size variable, 3rd is longest

Superior articular facets: concave, facing postero-medially (interlocking with inferior facets)

Spinous process/spine: sturdy, stumpy, quadrangular


What movements are associated with the lumbar region?

1. Extension is greatest movement
2. Then flexion
3. Some lateral flextion
4. No rotation


What are the faetures of the sacrum and coccyx from an anteroinferior view?

+ Sacral promontory
+ Ala
+ S1
+ Anterior foramen
+ Coccyx


What are the features of the sacrum and coccyx from a posterosuperior

+ Median crest
+ Intermediate crest
+ Lateral crest
+ Posterior foramen
+ Sacral hiatus


What are the two atypical vertebrae?

Atlas and Axis


What are the features of the atlas?

Anterior (short) and posterior (long) arches between two lateral masses but no body

Transverse process with foramen

Superior articular facets: concave oval to reciprocate with the occipital condyles

Inferior facets: flat, circular to articulate with the axis

Groove for vertebreal artery


What movements are associated with the atlas?

Flexion and extension at the atlanto-occipital joint


What are the features of the axis?

Body: with odontoid process or Dens for articulation with the anterior arch of the atlas

Transverse process with foramen

Vertebral foramen: large, triangular

Spinous process/spine is bifid

Superior articular facets: flat and circular to reciprocate with the inferior facets of the atlas


What movements are associated with the axis?

Rotation of the head and neck at the atlanto-axial joint, around the odontoid process


What are features of the joints of the vertebral colum?

1. Zygopophyseal facet joints: synovial with fibrous capsule and supportive ligaments

2. Intervertebral (IV) discs of fibrocartilage (symphysis or 2y cartilaginous joint)


Where in the vertebral column doe the spinal nerves emerge?

The intervertebral foramen


What are the boundaries of the intervertebral foramen?

1. Pedicle
2. Vertebral body
3. IV disc inferiorly


What are features of the IV discs?

+ They bind the ventral bodies together
+ Contribute to the shape of the spinal curvatures
+ Form 20-25% of the length of the column
+ Consist of the anulus fibrosus and the nucleus pulposus


What are features of the anulus fibrosus?

+ Very strong
+ Concentric lamellae of fibrocartilage


What are features of the nucleus pulposis?

+ Draws in water
+ Semi-fluid
+ Tense and resilient
+ Flexible


What are the functions of IV discs?

+ Strong, resilient shock-absorbers

+ Deform to allow movement between the vertebral bodies


IV discs have the ability to deform - what effect does this have on the discs?

+ Puts pressure on the nucleus pulposus

+ Anulus fibrosis may degenerate and weaken


What can happen to the nucleus pulposus when pressure is applied?

The nucleus may herniate or prolapse to compress:
- spinal cord (which stops at L1/2)
- cauda equina
- emerging spinal nerve


Where are disc herniations most likely to occur?

+ Most disc herniations are postero-lateral, towards the intervertebral foramen

+ This is due to the central position of the posterior longitudinal ligament


How does a prolapsed L5 disc manage to escape injury?

The disc forms the anterior aspect of the foramen, but inferiorly, so the spinal nerve probably emerges above the prolapsing disc and escapes injury

Consequently, a prolapsed L4 disc is likely to compress the L5 (and lower) nerves


Where are the anterior and posterior longitudinal ligaments in relation to the vertebral column?

+ Anterior and posterior longitudinal ligament are ant. and post. to vertebral bodies

+ Posterior ligament is anterior to spinal cord


What are features of the posterior longitudinal ligament?

+ Resists hyper-flexion
+ Narrow band
+ Attached mainly to discs
+ From C2 to sacrum


What are features of the anterior longitudinal ligament?

+ Limits extension
+ Thick, broad band
+ Attached to vertebral bodies and discs
+ Passes from occipital bone and atlas all the way to the sacrum


What are features of the ligamenta flava?

+ Limits sudden flexion
+ Supports the curvatures
+ Strong, elastic bands of varying thickness
+ Between the vertebral laminae
+ Left and right may meet and fuse in the midline


Where can the intertransverse ligaments be found?

Between all the transverse processes


What are features of the supraspinous ligaments?

+ Thick cords between tips of spines
+ From sacrum to C7 where it continues with the Ligamentum Nuchae


What are features of the interspinous ligaments?

+ Thin membrane
+ Found between all spines


What are features of the ligamentum nuchae (nuchal ligament)

+ In cervical region
+ Limits flexion
+ Provides muscle attachment
+ Broad, fibro-elastic band
+ From external occipital protuberance and posterior edge of foramen magnum down to C7


What structures does the ant. longitudinal ligament continue as?

+ Anterior atlanto-axial membrane

+ Atlanto-occipital membrane


What structure is the tectorial membrane a continuation of?

The posterior longitudinal ligament


What does the ligamentum flavum continue as?

+ Posterior atlanto-axial membrane

+ Atlanto-occipital membrane


Where do the alar ligaments attach?

From sides of dens to sides of foramen magnum


What is the function of the alar ligaments?

To stop excess rotation


What is the role of the inf. longitudinal bands of the cruciate ligament?

+ Bind together
+ Prevent excess movement between the acis, atlas and occiput (back of head)


Where is the transverse part of the crucial ligament located?

+ Spans the lateral masses of the atlas

+ Holds its anterior arch close to the dens


The aorta branches off to form arteries - how does the blood supply come about and where?

Arteries form anastomotic rings that arise segmentally from:
- vertebral arteries
- posterior intercostal and lumbar branches of aorta


What is facilitated by the venous plexuses?

The spread of tumours


Where do the basivertebral veins emerge?

Between the vertebral body and posterior longitudinal ligament


What are the muscles that form the superficial layer?

+ Trapezius
+ Latissimus dorsi
+ Levator scapulae
+ Rhomboid minor and major


What is another term for the deeper layer muscles?

Intrinsic (proper) muscles


What is the role of the intrinsic muscles?

Keep the vertebral column upright and in extension against gravity


Where do the intrinsic muscles range from?

Skull, through C, T, L regions to pelvis


How are the intrinsic muscles supplied?

Supplied segmentally by the dorsal rami of spinal nerves (also passing to the overlying skin)


What are the 3 layers that form the intrinsic muscles?

+ Superficial
+ Intermediate
+ Deep


What are the superficial intrinsic muscles of the back?

+ Splenius capitus
+ Splenius cervicis


Where do the superficial intrinsic muscles attach to?

+ Ligamentum nuchae
+ C & T spines
+ Trans processes and skull (laterally)


What is the intermediate intrinsic muscles of the back?

Erector spinae


What are features of the erector spinae?

+ Has 3 columns from lateral to medial, each subdivived 3 times depending on position


Where does the erector spinae cover?

From spines and supraspinous ligaments to ribs, trans processes and skull


What are the three colums of the erector spinae?

+ Iliocostalis
+ Longissimus
+ Spinalis


What is the deep intrinsic muscle of the back?



Where does the transversospinalis span from?

Trans processes upwards to spines


What are features of transversospinalis?

Consist of multiple small muscles:
- in between the spines
- in between the trans processes
- from trans processes to ribs


What is the role of the venous plexuses?

Venous plexuses, internal and external, coalesce and drain to the veins equivalent to the above arteries