Neuro: Viscerosomatic Sensation

Question 1

In the somatic sensory system, neurons of the ____ act as sensory receptors, and are the first order neurons in the somatosensory pathway.

Answer 1

DRG

Question 2

“_____ _____” sharpens contrast between stimuli across receptive fields, ensuring that the strongest of two or more competing signals is expressed in the cortex.

Answer 2

surround inhibition

Question 3

A ______ _____ is the region of space in which the presence of a stimulus will alter the firing of a particular neuron.

Answer 3

receptive field

Question 4

______ nociceptors are activated by intensive pressure applied to the skin using fast-conducting Αδ fibers.

Answer 4

Mechanical

Question 5

____-_____ receptors continue to produce action potentials over the duration of a stimulus and signal magnitude/intensity of a signal.

Answer 5

slow-adapting

Question 5

_____ nociceptors are found in joint capsules and ligaments, but not cartilage.

Answer 5

Joint

Question 7

What are the two types of mechanoreceptors in the superficial layer of the skin, and what sensations do they detect?

Answer 7

Meissner’s corpuscles - stroking/fluttering sensations Merkel’s disks - pressure

Question 7

Most _______ nociceptors are believed to be chemoreceptors sensitive to substances in the tissue produced by inflammation or ischemia

Answer 7

visceral

Question 8

Upon repeated application of noxious mechanical stimuli, previously unresponsive nociceptors become responsive. This is illustrative of what process?

Answer 8

peripheral sensitization

Question 9

Fast-conducting, fast-adapting fibers that respond to changes in muscle length, excite alpha motor neurons during deep tendon reflex and increase muscle tension.

Answer 9

Type 1a fibers

Question 9

Higher centers involved in the perception of pain incorrectly ascribing pain stimuli to the skin instead of the deeper visceral structure is a concept known as what?

Answer 9

Referred pain

Question 10

_____ nociceptors are located in connective tissue surrounding muscle fibers; activation results in poorly localized aching/cramping.

Answer 10

Muscle

Question 10

Condition whereby: • ↓ response threshold to noxious stimuli • ↑ response magnitude to noxious stimuli • ↑ response to innocuous stimuli • spontaneous pain experienced • large ↑ in receptive field size of central neurons

Answer 10

secondary hyperalgesia

Question 11

This special class of nociceptor does not respond at all to thermal, mechanical, or chemical stimuli unless injury has occurred, and their firing threshold is reduced by inflammation and chemical insults.

Answer 11

Silent nociceptors

Question 13

Fast-conducting fibers that respond to tendon stretch/muscle contraction, inhibiting alpha motor neurons and increasing muscle relaxation

Answer 13

Type 1b fibers

Question 15

____-_____ receptors diminish in response to stimuli very quickly and then stop firing until there is a change in stimulus intensity. They signal rate or velocity of a signal.

Answer 15

Fast-adapting

Question 16

______ nociceptors are activated by extreme temperatures (< 5°C or > 45°C) using fast-conducting Αδ fibers.

Answer 16

Thermal

Question 17

Condition whereby: • ↓ response threshold to noxious stimuli • ↑ response magnitude to noxious stimuli • spontaneous activation of nociceptors • small ↑ in receptive field size of nociceptors

Answer 17

primary hyperalgesia

Question 18

Fast-adapting receptors

Answer 18

Pacinian and Meissner’s corpuscles

Question 20

Slow-adapting receptors

Answer 20

Merkel’s disks and Ruffini endings

Question 21

What are the two types of mechanoreceptors in the deep subcutaneous tissue, and what sensations do they detect?

Answer 21

Pacinian corpuscles - vibration Ruffini endings - skin stretch

Question 22

All cutaneous mechanoreceptors use fast-conducting ____ fibers.

Answer 22

Aβ

Question 23

_____ nociceptors are activated by high-intensity chemical, mechanical, or thermal stimuli, using non-myelinated, slow-adapting C fibers

Answer 23

Polymodal

Question 24

A majority of visceral afferents are ____ and ___ fibers.

Answer 24

Aδ and C