Lecture 24

Question 1

feel pain 1st time

Answer 1

tissue damage, activate nociceptor, action potential go to spinal cord, release substance P in spinal cord, feel pain

Question 2

enhancement

Answer 2

mast cell release histamine, interact w/ nociceptor, more sensitive
cell ruptured release chemicals and interact w/ nociceptor, more sensitive
FB to blood vessel, dilate

Question 3

touch and proprioception

Answer 3

light stroke w/ a feather
travel up to spinal nerve, cervical spinal segment, CB at dorsal root ganglion
quick turn up to white matter
dorsal column carry ipsilateral touch and proprioception
enter brainstem
synapse at medulla
medial lemniscus carry contralateral touch and proprioception to thalamus, to somatosensory cortex

Question 4

T and pain

Answer 4

T and pain carry by afferent, go through dorsal spinal nerve to dorsal root ganglion
enter grey matter
synapse at second order neuron in spinal segment, cross over on the midline where central canal is, to anterolateral column
anterolateral column carry contralateral T and pain
branch in brain stem

Question 5

somatotopic map

Answer 5

hand face mouth highest acuity
somatosensory cortex damage cause contralateral loss to all somatosensation

Question 6

referred pain

Answer 6

brain know modality and location of almost all afferent
visceral & somatic pain

Question 7

descending pathway

Answer 7

neuron in midbrain & medulla receive input from other area of the brain
top down modulation
activate descending pathway
synapse stop release of substance P
morphine and opiate neurotransmitter

Question 8

eye anatomy

Answer 8

sclera巩膜, cornea角膜, pupil瞳孔, iris虹膜, lens, vitreous humor玻璃体, retina, optic nerve
blood vessel, fovea centralis中央凹, optic disk

Question 9

accommodation

Answer 9

limited focal range
ciliary muscle control lens shape

Question 10

common optical defect

Answer 10

eye is myopic近视
eye is hyperopic远视
astigmatism: lens or cornea not spherical散光
presbyopia: lens get stiff老花眼
cataract: lens become opaque白内障