Spine and Spinal Cord AR Flashcards
Vertebrae: What is the name of the bony process off the posterior of each vertebrae. It is directed back ward and downward from the junction of the laminae.
Spinous process
Vertebre: What is the name give to the two projections on each side of the vertebrae which project from either side at the point where the marina joins the pedicle?
Transverse process
Give the names of the follow parts of the vertebrae
a) Spinous process
b) Lamina
c) Articular process
d) Vertebral body
e) Pedicle
f) Spinal canal
g) Transverse process
What is the cauda equina?
A bundle of spinal nerves and spinal roots L2-L5, S1-S5 & C1 that origionate in the conus medullaris of the spinal cord
At which level of the spinal cord has the following been taken from?
a) Cervical
b) Thoracic
c) Lumbar
d) Sacral
a) Cervical
Note: The thicker ventral horn and lateral horn
At which level of the spinal cord has this been taken from?
a) Cervical
b) Thoracic
c) Lumbar
d) Sacral
Thoracic
Note: Small ventral horn
At which level of the spinal cord has the following been taken from?
a) Lumbar
b) Sacral
c) Cervical
d) Thoracic
Lumbar
At which level of the spinal cord has this been taken?
a) Lumbar
b) Sacral
c) Cervical
d) Thoracic
Where in the spinal cord do complex interactions occur to control the transmission of pain information to ascending spinothalamic and spinoreticular tract neurons?
The substantia gelatinosa
Why can rubbing a sore spot ease the pain?
Large-diameter afferents carrying infomation tactile infomation inhibits the transmission of nociceptive impulses to ascening tract neurons.
Match the grey matter horns (dorsal, lateral and ventral) with their description?
a) Contains preganglionic sympathetic neurons
b) The main site of termination of primary afferent fibres. It includes the substantia gelatinosa, which is important in the transmission of nocioceptive impulses to the brain.
c) Contains alpha and gamma motor neurons aka LMN
Dorsal = The main site of termination of primary afferent fibres. It includes the substantia gelatinosa, which is important in the transmission of nocioceptive impulses to the brain.
Lateral = Preganglionic sympathetic neurons
Ventral = Alpha and gamma motor neurons aka LMN
What are the 2 types of neurons in the ventral horn and what do they innervate?
Alpha motor neurons innervate extrafusal muscle fibers
Gamma motor neurones innervate intrafusal muscle fibers
Ventral horns are large at the cervical and lumbar enlargements
Explain how stretching the muscle can lead to muscle contraction
Stretch stimulates the sensory endings attached to the intrafusal muscle fibres
Afferent fibers carry impulses to the CNS where there is monosynaptic excitatory contact with alpha motor neurons
Alpha motor neurons innervate the extrafusal fibers and make the muscle contract
How is the sensitivity of the stretch reflex increased?
By the gammar motor neurones
- they innervate polar intrafusal muscle fibers which when contracted applies tension to the sensory endings. (lowers the threshold)
Describe the 1st order neuron in the ascending spinal tracts giving the point of entry to spinal cord, position of cell body.
1st order neurone:
Enters spinal cord @ dorsal root.
Cell body in dorsal root ganglia
Central process may collateralise & make synaptic connections
Main fibre stays on ipsilateral side
Synapses with 2nd order neurone in spinal grey matter/medulla depending on modality
