Sensory Physiology Flashcards
Pain receptors in the skin are typically classified as which of the following?
A. Encapsulated nerve endings
B. Single class of morphologically specialized receptors
C. The same type of receptor that detects position sense
D. Free nerve endings
Free nerve endings
Which of the following is best described as an elongated, encapsulated receptor found in the dermal pegs of glaborous skin that is especially abundant on lips and fingertips?
A. Merkel disc
B. Free nerve endings
C. Meissner Corpuscle
D. Ruffini endings
Meissner Corpuscle
Which of the following is the encapsulated receptor found deep in the skin throught the body as well as in fascial layers, where it detects indentation of the skin (pressure) and movement across the surface (vibration)?
A. Pacini corpuscle
B. Meissner’s Corpuscle
C. Free Nerve Endings
D. Ruffini Endings
Pacini corpuscle
Interneurons that utilize the neurotransmitter encephalin to inhibit afferent pain signals are most likely to be found in which region of the CNS?
A. Dorsal horn of the spinal cord
B. Postcentral gyrus
C. Alpha-delta fibers
D. C fibers
E. Ventral horn of the spinal cord
Dorsal horn of the spinal cord
Neurons originating in which area release serotonin as their neurotransmitter?
A. Periaqueductal gray area
B. Interneurons of the spinal cord
C. Periventricular area
D. Raphe Nucleus
Raphe Nucleus
You cut your finger with a pocketknife and immediately apply pressure to the damaged area of your hand with your other hand. Inhibition of pain signals by tactile stimulation of the skin is mediated by which type of afferent neurons from mechanoreceptors?
A. A-alpha
B. A-beta
C. A-delta
D. C fibers
A-beta
Which of the following brain areas contributes most directly to the descending pain suppression system?
A. Superior Olivary complex
B. Locus Ceruleus
C. Periaqueductal gray area
D. Amygdala
E. Insular Cortex
Periaqueductal gray area
The terminals of nociceptive afferents release which one of the following transmitters?
A. Substance P
B. GABA
C. Enkephalins
D. Serotonin
E. Acetylcholine
Substance P
A neuroscientist noticed attenuation of pain sensation in an experimental animal by stimulation of the periaqueducatal gray. Attentuation of pain sensation may be due to the release of a neurotransmitter from interneurons in the dorsal horn of the spinal cord, which inhibits the release of neurotranmitters from the central axonal endings of the pain-sensing neurons. Which one of the following neurotransmitters is released from the interneurons in the dorsal horn?
A. Enkephalin
B. Ach
C. Endorphin
D. CGRP
E. Histamine
Enkephalin
Within the primary somatosensory cortex, the various parts of the contralateral body surface are represented in areas of varying size that reflect which of the following?
A. THe relative size of the body region
B. Density of the specialized peripheral receptors
C. Size of the muscles in that body part
D. Conduction velocity of primary afferent fibers
Density of the specialized peripheral receptors
Peripheral nerves are classified by two schemes: 1. their contribution to a compound AP and 2. Based on fiber diameter, myelin thickness, and conduction velocity. How are these two schemes related?
The conduction velocity determines a fiber’s contribution to the compoun action potential
A-alpha fibers have what two associated afferent fibers?
A-alpha fibers have what conduction velocity?
C fibers have what associated afferent fibers?
C fibers have what conduction velocity?
A-alpha
Ia and Ib
80-120 (fast)
C fibers
IV
0.5-2 (slow)
Which of the following peripheral nerve fibers supply primary muscle spindles and golgi tendon organ?
A. A-alpha
B. A-beta
C. A-delta
D. C fibers
A-alpha
Which of the following peripheral nerve fibers supply secondary muscle spindles and skin mechanoreceptors?
A. A-alpha
B. A-beta
C. A-delta
D. C fibers
A-beta
Which of the following peripheral nerve fibers supply skin mechanoreceptors, thermal receptors, and nociceptors?
A. A-alpha
B. A-beta
C. A-delta
D. C fibers
A-delta
C-fibers