(20) Thalamus

Question 1

Pain pathway that relays info about pain intensity and localization

Answer 1

neospinothalamic

Question 2

pain pathway that relays emotional and visceral response to pain

Answer 2

paleo-spinalthalamic

Question 3

pathway that carries sharp well localized pain vs dull, throbbing an poorly localized pain

Answer 3

sharp = neo spinothalamic

dull = paleo-spinalthalamic

Question 4

thalamic nuclei that recevis info from neo-spinothalamic tract

Answer 4

VPM and VPL

Question 5

thalamic nuceli that recieve info from paleo-spinothalamic nuclei

Answer 5

DPM, CM, and PF

Question 6

what senses pain from temp > 43C? < 25C?

Answer 6

transient receptor potential channel 1 and 8

Question 7

What NT are used to transmit pain signals

Answer 7

glutamate, substance P, calcitonin-gene related peptide (CGRP)

Question 8

How are free nerve ending sensitized to pain?

Answer 8

infalmmation + release of substance P and CGRP allows for threshold for activation at the free nerve endings to be lowered

Question 9

Where in the spinal cord do nociceptive specific neurons lie?

Answer 9

dorsal horn (lamina I and II)
**alpha-delta and C fibers

Question 10

What cells are responsible for Wind Up phenomenon? (= signal amplification) Where are they found?

Answer 10

wide dynamic range neurons (WDRNs) via C fibers

dorsal horn at lamina V

Question 11

Describe the phenomenon

Answer 11

1. C fibers transmit repetitive APs trigger wind up
2. WDRNs depolarize and released Mg block on NMDA receptors
3. allows Ca to flow in
4. causes more Na channels to be inserted
5. K+ channels blocked
6. Lowered threshold and amplification of pain signal

== long lasting pain pathway stimulation

Question 12

What role does substance P play in wind up?

Answer 12

sustains WDRN depolarization

Question 13

What mech is it in which AB fibers activate dorsal column interneurons that inhibit WDRNs, therefore blunting pain

Answer 13

gate control mechanism

Question 14

What mech sends fibers from cortex, amygadala, and hypothalamus to the periaquaductal gray matter and reticular formaton that will in turn end fibers to lamina II to inhibit or facilitate pain

Answer 14

descending pathway

Question 15

Activation of opiod receptor blocks _____ therefore ____polarizing the cell

Answer 15

Ca opening and K+ from closing = hyperpolarizing

Question 16

Descirbe the visceral pain pathway

Answer 16

afferent fibers first synapsoe on intermediate gray zone neurons that travel with the dorsal column pathway to the VPL where they synapse and go to the somatosensory cortex

Question 17

How can chonic visceral pain be relieved (such as cancer pain)

Answer 17

small midline lesion of the dorsal column