Exam 3 Lecture 3

Question 1

Crossed Extensor Reflex: How does it Work? Right Side: Painful limb

Answer 1

Withdrawal affected limb by contracting the flexor muscle group [hamstring] and relaxing the extensor group [quad]

Question 2

What are the 4 Reflex Pathways?

Answer 2

Stretch [stretch sensors], Tendon [stretch sensors], Withdrawal/Flexor [response to pain], Crossed-Extensor[response to pain]

Question 3

Tension Reflex: How many interneurons are used? What are they? How do they work

Answer 3

2; excitatory and inhibitory
Excitatory - Reflex activation of the antagonistic muscle effect
Inhibitory - Inhibit activity in motor neuron

Question 4

Does the grey matter have myelinated fibers?

Answer 4

Yes, not enough to make white

Question 5

Compared to other Reflexes, what reflex uses the most interneurons?

Answer 5

The Crossed Extensor Reflex uses the most interneurons

Question 6

How do COX-2 and PG’s work in the Nociceptor and 2nd order neuron

Answer 6

More pain = more #’s of COX-2; produces PG’s which increase sensitivity to pain by increasing sensitivity to AP; Bind to PG-R’s

Question 7

Another name for Enkephalin Opiate Receptors

Answer 7

Mu

Question 8

Flexor/Withdrawal Reflex: How does it work

Answer 8

Slam foot into nail - activation of flexor muscle [hamstring], flex and pull leg away from pain; Antagonistic Muscle [extensor/relax quad]

Question 9

Slow Pain Pathway

Answer 9

C-Fiber Unmyelinated - Lamina 2, 3, 5 - AWC - Anterior Ascending Spinothalamic Tract - Brainstem - Thalamus [terminate in reticular formations in brainstem usually]

Question 10

Stretch Reflex: What is a stretch receptor?

Answer 10

Muscle Spindle [spring in muscle]

Question 11

Stretch Reflex: How it works

Answer 11

Push someone backwards, Quads would contract [extensor muscle] and Hamstrings would relax [antagonistic muscle, inhibitory connection, flexion muscle]

Question 12

What is an A2-R and how does it operate

Answer 12

On nociceptor and 2nd order neuron; increases cell wall permeability to K+, make the cell more (-); shuts down nociceptor and 2nd order neuron

Question 13

nACh-R: Where are Fetal channels located and why is this bad for Sux

Answer 13

@ NMJ and other parts of skeletal muscle [expressed by CNS when it sense something is wrong with the muscle/body] - Massive K+ hemorrhage due to increased nACh-R and them staying open longer

Question 14

nACh-R: Low Conductance Immature/Fetal Channel: Total Domains, Names, Binding Domains

Answer 14

5 Domains; A, A1, B1, Delta, Gamma [in between A, A1 - takes place of Epsilon]

Question 15

How does the sensory talk to the motor portion of the Reflex Pathways?

Answer 15

Direct connection between dorsal and ventral horn; OR Interneurons to cross-talk

Question 16

Flexor/Withdrawal Reflex: How far superior and inferior do the signals go?

Answer 16

2 vertebra above and 2 vertebra below

Question 17

How do Volatile Anesthetics work on the Nociceptor/2nd order neuron

Answer 17

Suppress CNS by increasing K+ permeability

Question 18

How do Mg++ supplements help with pain?

Answer 18

Block NDMA; not absorbed easily = diarrhea

Question 19

Does the Stretch Reflex need an Interneuron?

Answer 19

No; actually uses the least amount

Question 20

Tendon Reflex: Goal

Answer 20

Make sure intense amount of tension does not pull our muscles out of their insertion points

Question 21

What is INOS? What is it’s function in the nociceptor/2nd order neuron

Answer 21

Nitric Oxide synthase; At synapse, increases sensitivity to painful stimuli [less known than PG’s]

Question 22

Tension Reflex: How is it able to be worked around?

Answer 22

no clear answer; will not be activated when lifting a 5000 lb car off a kitten

Question 23

Crossed Extensor Reflex: Does this reflex use interneurons? If so, which ones?

Answer 23

Yes; ones for cross talk and ascending/descending interneurons

Question 24

Flexor/Withdrawal Reflex: Where are the ascending/descending interneurons located? What is the name of this location

Answer 24

Posterior part of the dorsal horn between the horn and the border of the cord; this WHITE space is called the Tract of Lissaur

Question 25

What does the muscle need to work properly, per lecture?

Answer 25

Contraction and Flexion

Question 26

Fast Pain Pathway

Answer 26

A-Delta Myelinated - Lamina 1 - AWC - Lateral Spinothalamic Tract - Ventrobasal Complex - PL [similar to DCML]

Question 27

nACh-R: Why are the Mature/Adult channels known as “High-Conductance”

Answer 27

When open, ions move fast through the channel; they stay open a short period of time

Question 28

Drugs that bind to A2-R, least to most specific

Answer 28

Xylazine [tranq], Clonidine, Precedex [highest]

Question 29

nACh-R: Why are the immature/fetal channels known as “Low-Conductance”

Answer 29

When open, ions move slower through the channel; they stay open longer than Mature channels

Question 30

Are reflexes one or both sides of the body?

Answer 30

Can be both

Question 31

Stretch Reflex: Goal?

Answer 31

Keep muscles a constant length, SUPPORT, Keep posture constant

Question 32

Another name for the 2nd Order Descending Neuron

Answer 32

Serotonergic Neuron

Question 33

Flexor/Withdrawal Reflex: Does it involve interneurons? Which kinds

Answer 33

Yes; ascending and descending to get multiple parts of the cord involved

Question 34

nACh-R High Conductance Mature/Adult Channel: Total Domains, Names, Binding Domains

Answer 34

5 total; A, A1, B1, Delta, Epsilon [between A, A1]

Question 35

nACh-R: A7 for Depolarization: Total domains, Name

Answer 35

7; All Alpha domains [all for binding]

Question 36

Tension Reflex: How does it sense tension?

Answer 36

With golgi tendon sensors imbedded within tendons

Question 37

Tension Reflex: How Does it work?

Answer 37

Increased Tension in Quad = Inhibitory IN would stop flexion in quad and excitatory IN would contract hamstring

Question 38

Where is the 3rd descending neuron [Enkephalin] located?

Answer 38

Cell body outside dorsal horn with extension protruding in the dorsal horn grey matter

Question 39

How can the 4 Reflex Pathways be inhibited?

Answer 39

Spinal blocks/ meds

Question 40

Stretch Reflex: Clinical Testing

Answer 40

Tap on ligament inferior to Patella, patella drops down, foot moves forward, quad contracts

Question 41

Crossed Extensor Reflex: How does it work? Left side: Non-Painful Limb

Answer 41

Plant left leg and contract extensor muscles in Left leg [quads]; Relax antagonistic muscle set/Flexor in this case [Hamstrings]

Question 42

Crossed Extensor Reflex: Which side of the cord is used? When is this reflex important to use?

Answer 42

both sides of the cord are used; important when in motion/moving around

Question 43

What is an Opiate-R and how does it operate?

Answer 43

GPCR on nociceptor and 2nd order neuron; increases cell wall permeability to K+; making the cell more (-)

Question 44

Flexor/Withdrawal Reflex: Goal

Answer 44

want to withdrawal limbs from painful stimuli to prevent injury