Lecture 21 - Back and Vertebrae Flashcards
What shape is the primary curve of the vertebral common?
C-shaped
What part of the body does prostate/ovarian cancer tend to metastasize to first?
The back.
Why can osteophytes cause pain?
New bone might impinge at critical spaces, such as the vertebral foramina.
Why are the lumbar vertebrae larger than other vertebrae? Why is L5 the largest vertebra?
Lumbar vertebrae are large because they need to bear the most weight. L5 bears the most weight.
At what vertebral level does the spinal chord end?
Between L1 and L2
What exits the vertebral column via the intervertebral foramen?
Nerves (ventral and dorsal roots), arteries, and veins.
Is the image shown a joint that belongs to lumbar vertebrae or thoracic vertebrae? Explain how you can tell.
Thoracic; the joint is in the coronal plane so it allows limited ROTATION (also, minimal lateral flexion and forward flexion), which is the characteristic movement in the thoracic spine.
Disc prolapse is most common between which two intervertebral discs?
L5/S1 intervertebral disc
What is disc prolapse?
The annulus is torn and the nucleus (which is deformable) is squeezed down the defect in the annulus.
What structure does the spinal chord take after L1/L2?
Cauda equina - horses tail (latin)
How many cervical nerves are there?
8
True or false: mixed spinal nerves contain both motor and sensory fibres
True
Extrusion, if repaired, may leave nuclear fragments in the spinal canal and thus cause irritation. What is the name of the medical procedure of removing this fragment?
Laminectomy
What part of the vertebrae is shown? What are their different names?
They are colled ‘processes’
Middle: spinous process
Lateral 2: transverse processes
Where are the dorsal horn of the spinal cord?
The ‘back’ horn of the spinal cord touches the ‘back’ of the spinal cord.
Ie, the dorsal horns of white matter are the two horns that contact the outer edge of the spinal cord. The ventral horns of white matter do not touch the outer edge.
What are the four extrinsic muscles of the back? What are each of their primary movement(s)?
Latissimus dorsi - adduction of the humerus and extension at the shoulder
Rhomboid major and rhomboid minor - scapula adduction
Trapezius - retraction, medial rotation, and depression of the scapula
Levator scapulae - lifts the scapula
Intervertebral discs are made of which two structures?
Nucleus pulposus
Annulus fibrosus
At what age and why does the secondary cervical curve form?
Around about 6 months after birth the baby starts to develop the secondary cervical curve by the strengthening of the muscles in the neck.
What part of the annulus fibrosus is innervated?
Outer 1/3
What distinguishes the thoracic vertebrae from other vertebrae?
Thoracic vertebra have two attachments for the ribs: one for the tubicles of the rib and one for the head of the rib. Thus, they also have hylaine cartilage.
What makes a back muscle ‘intrinsic’?
Its insertion and origin are in the back
Which two parts of the vertebral column are fused?
The coccyx and sacrum are fused.
What is the most comon direction of disc prolapse? What movement causes more disc prolapse than other movements?
Posteriorlateral; Twisting/rotation of the trunk (often while weight bearing)
Erector spinae are responsible for what postural eccentric movement?
Controlling flexion
What is the ligament shown?
Ligamentum flavum
What makes a back muscle ‘extrinsic’?
Its insertion is in the upper limb and its origin is in the back
What movement(s) are guided allowed by lumbar and thoracic spine?
Lumbar: flexion/extension
Thoracic: rotation
Is the image shown a joint that belongs to lumbar vertebrae or thoracic vertebrae? Explain how you can tell.
Lumbar; the joint is in the sagittal plane so it allows flexion and extension, which is the movement in the lumbar spine.
Where is the dorsal root ganglion always located?
Dorsal root ganglion for a particular spinal segment is always located in the intervertebral foramina.
At what age and why does the secondary lumbar curve form? What is this curve called?
Strengthening of the muscles in the lumbar spine around 12+ months from walking. IE, creates the lordosis in the lumbar spine.
Which part of the vertebra is the laminar?
What are the three degrees of disc prolapse? (Least severe to most severe)
Bulge = degeneration
Herniation
Extrusion
What is scoliosis?
Scoliosis is an abnormal lateral curvature of the vertebral column (ie, to the side.)
What are the two postural movements performed by the transversospinae?
Extension and rotation of the spine
What are the two types of muscles in the back?
Intrinsic and extrinsic
Which vertebrae belong to the “back”?
T1 to the tip of the coccyx
What ligament is being pointed to?
Posterior longitudinal ligament
What happens to the annulus fibrosus as you age? Why is this bad?
It narrows/thins; increases the likelyhood of injury because it is not as strong.
Erector spinae are responsible for what postural concentrentric movement?
Extension
What and where is the nucleus pulposus? What is its role?
Middle of the annulus fibrosus. Nucleus of incompressable but deformable ‘gel.’ Its role is to keep the vertebra a part at a fixed distance.
If there are only 7 cervical vertebrae, how is there 8 cervical nerves?
First cervical nerves comes out above C1, and last comes out below C7. Thus, there are 8 cervical nerves
Which vertebrate are independent of other vertebrate?
From C1-L5 are all independent. THe sacrum and coccyx are fused
What is a common spinal injury in elderly people?
Compression fractures because of deterioration.
Are all the fibres in the annulus fibrosus in the same plane?
No
What part of the vertebrae is shown:
The body
The image shows an interbertebrate disc of an elderly man. What are the boney outgrowths called? Why have they developed?
Osteophytes. As the articular cartilage of the intervertebral joints deteriorates with age the body tries to compensate and limit movement by developing osteophytes.
Why does the ligamentum flavum have elastic tissue in it?
Allows stretching during flexion without compromising the space inside the vertebral canal and without impringing on the nerve fibres during extension.
Which has a higher proportion of elastic tissue: posterior longitudinal ligament and the ligamentum flavum?
The ligamentum flavum
What and where is the annulus fibrosus? What is its role? What is it reinforced by?
Annulus fibrosus is fibrocartilage that attaches to vertebral body and stops the vertebrae from separating. It is the exterior fibrocartilage surrounding the nucleus pulposus. It is reinforced by ligaments.
What are the two roles of the ligaments of the vertebral colum?
Reinforce the annulus fibrosus AND limit the range of motion of the vertebral column.
Why are intervertabral discs more hydrated during the morning than at night? And more in younger people than in older people?
Spine compresses over course of day under the weight of the body, and with age as the joints deteriorates.
Why are herniation and extrusions painful but bulges are not?
Herniation and extrusions: ay impinge on spinal cord or nerve roots (especially if posteriorlateral prolapse) and damage to the outer 1/3 of the annulus fibrosus.
Bulges: Probably won’t do either of the above.
What movement is the most likely to injure the annular fibres in the annulus fibrosus? Why?
Twisting; the annulus fibrosus is organised in layers of perpendicular rings so only ~50% of the fibres are positioned to resist twisting.
Why do the basivertebral veins allow bidirectional flow? Where are they located?
They have no valves; they are located in the vertebral foramina.
In relation to disc prolapse, what is the most important role of the longitudinal ligament?
To help prevent disc prolapse from impinging on the spinal cord.
What part of the vertebrae is shown:
Articular processes
