3.1 + 3.2 Spinal cord anatomy

Question 1

What is lumbar cistern

Answer 1

enlarged space in the subarachnoid filled with CSF, the arachnoid and dura mater do not extend down this far hence lumbar puncture can be performed here

Question 2

where does the spinal cord terminate

Answer 2

L1

Question 3

where are the two spinal enlargements 2

Answer 3

cervical enlargement which is origin of brachial plexus

c3-t2

lumbar enlargement where the lumbarsacral plexus originates from

L1-S3

Question 4

distribution of grey and white matter at different layers of the spinal cord

Answer 4

at cervical and thoracic more white than grey as more sensation than innervation

at lumbar more grey than white as more innervation then sensation

Question 5

what does the posterior portion of the spinal cord

Answer 5

the dorsal columns, responsible for the Dorsal Column Medial Lemniscus responsible for fine touch and proprioception

Question 6

what does the anterior segment of the spinal cord represent

Answer 6

the antero spinothalamic tract involved in crude touch

the anterior corticospinal tract

Question 7

what does the lateral columns of the spinal trcat represent

Answer 7

the lateral corticospinal tract for movement and the lateral spinothalamic tract for pain and temperature

Question 8

what are the ascending columns in the spinal cord 3

Answer 8

lateral spinothalamic tract
anterior spinothalamic tract
dorsal column medial lemniscus

Question 9

what are the descending columns in the spinal tract 3

Answer 9

lateral and anterior corticospinal tract

extrapyramidal tracts

Question 10

what is the function of extrapyramidal tracts 2

Answer 10

involved in involuntary and autonomic muscle control including tone, balance, posture and locomotion

Question 11

the dorsal columns can be further divided into two segments. Name function and position; either medial or lateral

Answer 11

Fasiculus cuneatus: responsible for upper limbs
lateral

Fasiculus gracilis:
responsible for lower limbs
medial

Question 12

primary vascular supply of the spinal cord 3

Answer 12

anterior spinal artery

paired posterior spinal arteries

segmented medullary arteries

Question 13

spinal reflex

Answer 13

involuntary, autonomic response which bypasses the brain and is mediated by the spinal cord

Question 14

stretch reflex characteristics

Answer 14

monosynaptic

muscle spindle

Question 15

golgi tendon reflex characteristic

Answer 15

polysynaptic

golgi tendon

Question 16

crossed extensor reflex

Answer 16

simultaneous extension of the opposite limb to balance withdrawl reflex.

Question 17

withdrawl reflex

Answer 17

rapid withdrawl of a body part from a painful stimulus

Question 18

what are spinal reflexes modulated by 3

Answer 18

descending brain signals
local interneurons
sensory feedback

pain
emotional state
ongoing motor activity

Question 19

dermatome

Answer 19

specific area of skin innervated by sensory fibres along a spinal nerve root

Question 20

myotome

Answer 20

groups of muscles that are innervated by motor fibres along a spinal nerve root

Question 21

what substance does the sympathetic system use to communicate with a target cell

Answer 21

noradrenaline, only exception is acetylcholine to stimulate sweat glands

Question 22

what substance does the parasympathetic system use to communicate with an end cell/organ

Answer 22

acetylcholine

Question 23

alpha receptors 1 and 2 action

Answer 23

smooth muscle contraction

examples include: vasoconstriction, sphincter constriction, arrector pili contraction

Question 24

beta receptors 2 and 3

Answer 24

smooth muscle relaxation

ex. vasodilation, urination, digestion, bronchodilation

Question 25

beta receptor 1

Answer 25

cardiac muscle contraction

Question 26

what are the receptors associated with the parasympathetic system

Answer 26

muscarinic

Question 27

paravertebral ganglia

Answer 27

fibres associated with the sympathetic chain most preganglionic fibres will synapse here there will be two destinations after this; either back to the spinal cord or to form a splanchnic nerve

Question 28

sns structure in terms of pre ganglionic and post ganglionic

Answer 28

pre ganglionic is short post ganglionic is long

Question 29

pre-vertebral ganglia

Answer 29

lie anterior to vertebral column there are three groups preganglionic neuron will form abdominopelvic splanchnic nerve synapsing here will then go onto to innervate the visceral organs of the abdomen and pelvis a branch will also go to the adrenal medulla

Question 30

what is the name for a pre ganglionic neuron which goes to the pre-vertebral ganglia

Answer 30

abdominosplanchnic nerve

Question 31

parietal distribution

Answer 31

post ganglionic neurons in the paravertebral ganglia which return via the grey ramus to the spinal nerve

Question 32

visceral distribution

Answer 32

post ganglionic neurons in the paravertebral ganglia which form the splachnic nerve to innervate visceral targets

Question 33

where does the PNS arise from 2

Answer 33

brainstem and grey matter of sacral segments s2 to s4

Question 34

pns structure in terms of preganglionic and post ganglionic

Answer 34

long pre ganglionic short post ganglionic

Question 35

5 main controls of autonomic nervous system

Answer 35

hypothalamus limbic system amygdala spinal and brainstem reflexes

Question 36

parasympathetic activity on the lense 4

Answer 36

activates ciliary muscle causes it to contract lens bulges near vision

Question 37

sympathetic activity on the lense

Answer 37

activation of ciliary body relaxation of muscle lens flattens far vision

Question 38

the structure of parasympathetic innervation of the eye

Answer 38

Edinger westphal nucleus in occulomotor nerve postganglionic neurons in the ciliary ganglia leave as short ciliary nerves which innervate the iris and ciliary muscle

Question 39

the structure of sympathetic innervation of the eye

Answer 39

arise from t1-t6 synapse with superior ciliary ganglia form short and long ciliary nerves which go to synapse with the eye

Question 40

horner's syndrome

Answer 40

interruption of sympathetic activity to the eye

Question 41

signs of horners syndrome

Answer 41

partial ptosis mitosis = pupil constriction anhydrosis