PBL 1 Flashcards
what are the 4 main functions of the vertebral column?
protects the spinal cord, supports the wight of the body, forms the central axis of the body, has roles in posture and movement
what are the superior and inferior aspects of the vertebral body lined with?
hyaline cartilage
what type of cartilage are intervertebral discs made out of?
fibrocartilage
what are the pedicles of the vertebral arch?
they connect the vertebral body to the transverse processes
what are lamina of the vertebral arch?
they connect transverse and spinous processes
what are articular processes of the vertebral arch?
where are they located?
they form joints between the superior and inferior vertebra.
located at the intersection of the laminae and pedicles
what is the anterior ligament?
The anterior longitudinal ligament is thick and prevents hyperextension of the vertebral column.
what is the posterior ligament?
The posterior longitudinal ligament is weaker and prevents hyperflexion.
what are the 3 ligaments that strengthen the facet joints?
ligamentum flavum, interspinous and supraspinous ligaments, inter transverse ligaments
what is the ligament flavum?
connect ventral parts of laminae between adjacent vertebrae. It helps to preserve the normal curvature of the spine and to straighten the column after it has been flexed.
what are the interspinous and supraspinous ligaments?
interspinous joint ligaments attach between spinous processes of adjacent vertebrae whilst the supraspinous ligaments attaches to the tips
what are the inter transverse ligaments?
they extend between the transverse processes.
what are nociceptors?
free nerve endings in every tissue apart from the brain
what is superficial somatic pain?
pain that arises from stimulation of receptors in the skin
what is deep somatic pain?
pain that arises from stimulation of pain receptors in skeletal muscles, joints, tendons and fascia
what is visceral pain?
pain that results from stimulation of nociceptors in visceral organs
what are NSAIDs mechanism of action?
they inhibit COX 1 and 2 which prevents the conversion of arachidonic acid to prostaglandins without prostaglandins we cannot get depolarisation and so an act potential can’t be formed.`
what are opiates mechanism of action?
Opioids close N-type voltage-operated calcium channels and open calcium-dependent inwardly-rectifying potassium channels. This results in hyperpolarization and a reduction in neuronal excitability.
in the descending pain pathway, where do the first order neurones arise?
where does it synapse with the 2nd order neurone?
how does this 2nd order neuron inhibit the ascending pain pathway?
periaqueductal grey matter
in the nucleus Raphe magnus
it travels to the dorsal horn of the spinal cord and releases serotonin, nor-adrenaline and stimulates an interneurone within the substantial gelatinosa to release enkephalin (an endogenous opiod)
what effect do serotonin and nor-adrenaline have in the descending pathway?
they inhibit the release of substance P
what effect does enkephalin have in the descending pathway?
it inhibits substance P release from pre-synaptic neurones and inhibits depolarisation of the 2nd order neuron
what is the substantial gelatinosa?
a collection of cells in the dorsal horns of the spinal cord
what is spondylosis?
general degeneration of the spin associated with normal wear and tear
what are sprains?
what are strains?
tearing/over-stretching a ligament
tears in tendons or muscles
what is intervertebral disc degeneration?
when the usual rubbery discs lose integrity as a normal process of ageing- they lose their cushioning ability, become less flexible and are therefore more prone to tearing or rupturing
what are herniated discs?
outer fibres of the intervertebral discs can become injured and the nucleus pulpous can bulge outwards or rupture out of its enclosed space
what is Radiculopathy?
compression, inflammation or injury on a spinal nerve root can cause pain, numbness, tingling that radiates to other areas of the body that are also served by the same spinal nerve root.
what is sciatica?
compression of the sciatic nerve which causes shock-like or burning lower back pain combined with pain. down the back of the leg. this can be caused by a tumour or cyst.
what is spondylolisthesis?
vertebra of the lower spine slips out of place, pinching the nerves exiting the spinal column.
what is spinal stenosis?
narrowing of the spinal column that puts pressure on the spinal cord and nerves that can cause pain or numbness with walking and over time leads to leg weakness and sensory loss.
what is scoliosis?
a curvature of the spine that does not usually cause pain until middle age
what is lordosis?
an abnormally accentuated arch in the lower back
describe the structure of the intervertebral discs?
the central area is composed of a colloidal gel called the nucleus pulposus. it is surrounded by the annulus fibrosis (a fibrous capsule)
where is the most common site of disc herniation?
why?
L5/S1
due to the thinning of the posterior longitudinal ligament as it extends caudally