Dr. Johnson & Dr. Hayward's lectures

Question 1

relationship btw spinal cord and vertebral column

Answer 1

there is a mismatch. there is one more cervical spinal segment than vertebral segment (8 vs 7). the spinal cord ends after vertebral L6, then the dorsal and ventral roots form the cauda equina

Question 2

divergence

Answer 2

• Divergence: one presynaptic neuron may synapse with a few to many thousand postsynaptic neurons

Question 3

convergence

Answer 3

• Convergence: neurons can have input from several other neurons

Question 4

withdrawl (nociceptive) reflex vs. acute pain perception

Answer 4

• with acute pain the patient will turn their head, cry out, or try to bite
• the withdrawl/nociceptive reflex is only dependent on the completion of the reflex arc in the spinal cord.
• a pain response REQUIRES that the information travels to the CEREBRAL CORTEX

Question 5

A-beta receptors

Answer 5

myelinated, convey touch - cutaneous receptors

Question 6

A-delta receptors

Answer 6

myelinated, convey pain, touch, and temp - cutaneous receptors

Question 7

C receptors

Answer 7

unmyelinated, convey pain - cutaneous receptors

Question 8

spinal pathway - upper body

Answer 8

DRG>cuneate funiculus>cuneate nucleus (synapse here)>internal arcuate fibers>medial lemniscus>VCL>internal capsule>somatosensory cortex

Question 9

spinal pathway - lower body

Answer 9

DRG>gracile funiculus>gracile nucleus (synapse here)>internal arcuate fibers>medial lemniscus>VCL>internal capsule>somatosensory cortex

Question 10

test for conscious proprioception

Answer 10

tactile placing response
-when an animal’s foot is placed on the dorsal surface it will lift the foot and plant the palmar surface on the ground. requires intact CORTEX and consciousness

Question 11

pain

Answer 11

a sensory perception of a nociceptive event (consciousness/cerebral cortex)

Question 12

pain - sensory type

Answer 12

discriminative

Question 13

pain - motivational type

Answer 13

affective dimension

Question 14

nociception

Answer 14

encoding and processing of harmful stimuli in the nervous system (the ability of a body to sense potential harm)

Question 15

nociceptors

Answer 15

have free nerve endigns in skin and viscera

Question 16

nociceptor fibers

Answer 16

A delta and C

Question 17

T/F: nociceptors have high activation thresholds, increase their response magnitude throughout noxious range

Answer 17

True

Question 18

spinal -descending pathway

Answer 18

somatic sensory cortex>midbrain periaqueductal gray>dorsal horn of spinal cord>ascending nociceptive pathways

Question 19

parasympathetic division of ANS

Answer 19

craniosacral origin, rest & digest, postganglionic neurotransmitter is ACh

Question 20

sympathetic division of ANS

Answer 20

thoracolumbar origin, fight or flight, postganglionic neurotranmitter is ANS-division specific

Question 21

visceral pain

Answer 21

poorly localized, blockage in a hollow organ, stretch of capsule in a solid organ

Question 22

referred pain

Answer 22

due to overlying serosal inflammation of viscerosomatic convergence

Question 23

rheobase:

Answer 23

the lowest possible stimulus that will elicit an AP

Question 24

chronaxie:

Answer 24

2x rheobase (the minimum time required for an electric current double the strength of the rheobase to stimulate a muscle)

Question 25

absolute refractory period

Answer 25

time during which an AP can be generated with a greater than normal stimulus

Question 26

If you shift concentrations of Na+ in

Answer 26

depolarization

Question 27

If you shift concentrations of Na+ out

Answer 27

hyperpolarization

Question 28

If you shift concentrations of K+ in

Answer 28

hyperpolarization

Question 29

If you shift concentrations of K+ out

Answer 29

depolarization

Question 30

axon conduction velocity

Answer 30

dependent on axon membrane capacitance and internal resistance

Question 31

salutatory conduction

Answer 31

made possible by properties of the lipid material in the myelin sheath

Question 32

action potential vs. general potential

Answer 32

• action potential is “all or nothing”

- generator potential is graded, increasing in amplitude with increasing stimulus intensity, no refractory period

Question 33

The influx of ______ triggers the release of quanta into the synaptic cleft

Answer 33

Ca2+

Question 34

EPSP:

Answer 34

the neurotransmitter acts by briefly increasing the permeability of the post synaptic membrane primarily to Na+ and K+

Question 35

IPSP:

Answer 35

inhibitory neurotransmitters bind to receptors that increase the permeability of the post synaptic membrane to Cl-; Cl- flows into the cell, hyperpolarizing the local membrane

Question 36

excitatory post synaptic potentials

Answer 36

inward flux of Na+ is greater than the outward flux of K+ , leadng to a breif depolarization,

Question 37

inhibitory post synaptic potentials

Answer 37

associated with the presynaptic release of inhibitory neurotransmitters that results in a transient hyperpolarization of the post synaptic membrane