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Flashcards in Anatomy 2 Deck (215)
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where is the epidural space

outside the dura in the spinal chord


where is anaesthesia injected in caudal anaesthesia

sacral hiatus


where is epidural anaesthesia inserted

subarachnoid space surrounding cauda equina where vertebrae arent fused (l3/4 interface)


where does the subarachnoid space end



when do you not perform a lumbar puncture

when there is raised ICP


what does the needle go through in an epidural

supraspinous ligament
interspinous ligament
ligamentum flavum
epidural space (fat and veins)


what does the needle go through in a lumbar puncture

supraspinous ligament
interspinous ligament
ligamentum flavum
epidural space (fat and veins)
dura mater
arachnoid mater
(reaches subarachnoid space)


what is a laminectomy

removal or one or more spinous processes and the adjacent lamina

used to access spinal cord/ spinal roots or to relieve spinal cord or nerve roots (tumour, herniated disc, bone hypertrophy)


as spinal nerves pass through the intervertebral foramina why is the posterior root enlarged

by the dorsal (posterior) root ganglion


what is the conus medullaris

where the spinal cord terminates


why is the posterior root enlarged as it leaves the intervetebral foramina

enlarged by dorsal root ganglion


what suspends the spinal cord in the canal

denticulate ligament


what is in the white matter of the spinal cord

axons, glial cells, blood vessels


what is in the grey matter of the spinal cord

soma, cell processes, synapses, glia and blood vessels


what is the lateral horn

at levels T1-L2 there is a smaller horn which contains the preganglionic sympathetic neurones


what is the blood supply of the spinal cord

3 longitudinal arteries (1 ant 2 post) that original from vertebral arteries
segmental arteries
radial arteries (travel along roots)

venous has longitudinal and segmental vessels also in epidural space


the right side of the cortex represents which side of the body



where is the primary somatosensory cortex

post central gyrus (poSt = Sensory)


describe the dorsal column/ medial lemniscus

ascending tract for fine touch and proprioception

enter dorsal column
sypanse in medulla @ nucleus gracillus- where it crosses to midline
goes to thalamus
the PostCG


describe the spinothalamic tract

ascending tract for pain, temp and deep pressure

synapse immediately in posterior horn and ascended on CONTRAlateral side
synapses in thalamus

fibres cross Segmentally= Switch Sides Straight away as they enter cord= Spinothalamic


what is the primary motor cortex

pre central gyrus


describe the corticospinal tract

descending tract for fine precise movement (esp digits)

cortex PreCG
85% of fibres cross at the decussation of the pyramids in the medulla (forming the lateral CST)
other 15% form ventral CST which cross segmentally (at level they leave cord)


what are pyramidal tracts

corticospinal tract forms these on the anterior surface of the medulla- 85% of fibres cross here in medulla


what is the internal capsule

white matter strip where lots of sensory information (e.g. CST) travels through)


what happens if there is a CVS in the internal capsule

lack of descending control of the corticospinal tract which results in a spastic paralysis with hyperflexion of the upper limbs = decorticate posturing.


describe the tecto spinal tract

begins in tectum (post. mid brain)
dorsal tegmental decussation
mediates head and neck reflec to visual stimuli


decsribe the reticulospinal tract

Network of nuclei in the brainstem that control breathing, cardiac


describe the vestibulospinal tract

Fibres originate in the vestibular nuclei of pons and medulla

project down cord ipsilaterally

excite anti gravity extensor muscles


in general what motor influence do fibres from the pons and medulla do

Fibres originating in pons facilitate extensor movements and inhibit flexor movements, while those originating in the medulla do the opposite


when do you get decerebrate regidity and paraplegia in extension

Lesions of the brainstem at the level of the midbrain can result in a lack of descending cortical control of the vestibulosponal tract. This leads to domination of extensor muscle tone and hyperextended spastic paralysis.