Sensory Notes

Question 1

perception of senses is in

Answer 1

thalamus

Question 2

pain sensation of of ischaemia is recognised by sensory cortex through

Answer 2

release of metabolites (lactic acid) hypoxic damage of tissue → release of PPS

Question 3

muscle spasm are a direct mechanical effect of

Answer 3

ischaemia

Question 4

how do postglandines and substance p stimulate pain receptors

Answer 4

cause pain by lowering the threshold of the receptors

Question 5

superficial somatic pain and deep somatic pain are transmitted by

Answer 5

somatic nerves

Question 6

visceral pain is transmitted by

Answer 6

autonomic nerves

Question 7

mild pain stimulates what part of the brain

Answer 7

posterior hypothalamus triggering sympathetic system which leads to

                    - tachycardia 
                    - increase blood pressure
                    - pupillodilation 
                    - increased respiration

Question 8

severe pain stimulates what part of the brain

Answer 8

anterior hypothalamus triggering parasympathetic system which leads to

                    - bradycardia 
                    - hypotension
                    - sweating

Question 9

stimulation of large fibre afferents from an area from which pain is being initiated inhibits slow pain presynaptically

Answer 9

gating in substantia gelatinous

Question 10

hemisection of spinal cord

Answer 10

browns sequard syndrome

Question 11

damage to one half of the spinal cord

Answer 11

hemisection of spinal cord

Question 12

effects of hemisection of spinal cord aka brown sequard

Answer 12

• at the level of the lesion on the same side
  - loss of all sensation
  - lower motor neuron lesion
• below the level of the lesion on the same side
  - loss of fine touch and fine pressure position
  vibration senses
• below the level of the lesion on the opposite side
  - loss of pain temperature and crude touch
  sensations

Question 13

degeneration around central canal loss of pain temperature crude touch and pressure sensation on both sides

Answer 13

syringomyleia

Question 14

damage of the dorsal root central to the dorsal root ganglia

Answer 14

tabes dorsalis

Question 15

effects of tabes dorsalis

Answer 15

loss of fine touch position vibration pain temperature sensations and all reflexes on the same side

Question 16

tutors of spinal cord affect which area first

Answer 16

spinothalamic which sacral and lumbar affected first

Question 17

symptoms of loss of pain and temperature sensations an indication of

Answer 17

tumor of spinal cord

Question 18

intraspinal tumors cause anesthesia first in

Answer 18

higher segments

Question 19

pontine and midbrain lesions leads to

Answer 19

loss of all sensation in contralateral side

Question 20

lateral medullary syndrome

Answer 20

neurological disorder due to ischemia in the lateral part of the medulla oblongata in the brainstem the ischemia is a result of a blockage most commonly in the vertebral artery or the posterior inferior cerebellar artery.

Question 21

effects of lateral medullary syndrome

Answer 21

ipsilateral spinothalamic sensory loss in the face contralateral spinothalamic loss in the body

Question 22

effects of thalamic lesions

Answer 22

spontaneous pain exaggerated response to painful stimuli loss of other sensations on the contralateral side of the body

Question 23

effects of unilateral lesion in posterior limbs of internal capsule

Answer 23

loss of sensation in opposite side of body

Question 24

causes of thalamic lesions

Answer 24

haemorrhage ischemia migraines thiamine deficiency cerebral lupus

Question 25

cause of unilateral lesion in posterior limbs of internal capsule

Answer 25

stroke within capsule

Question 26

causes cortisol lesion in primary somatosensory area

Answer 26

agraphesthsia
asterognosia
hemihypesthesia
hemineglect

Question 27

effect of cortical lesion in primary somatosensory area

Answer 27

loss of topognosis loss of stereognosis loss of two-point discrimination

Question 28

effect of cortical lesion in secondary somatosensory area

Answer 28

amorphosynthesis (sensory inattention) high cortisol level hysterical sensory loss