Somatosensory Receptors

Question 1

what are the mechanoreceptive somatic senses?

Answer 1

include both tactile and position sensations that are stimulated by mechanical displacement of some tissue of the body

Question 2

what are the the thermoreceptive senses?

Answer 2

detect heat and cold

Question 3

what is the pain sense?

Answer 3

activated by any factor that damages the tissues, these have free nerve endings

Question 4

in terms of mechanoreceptors, what are the very rapidly adapting mechanoreceptors?

Answer 4

the pacinian corpuscle

Question 5

what layer of the skin would you find the pacinian corpuscle?

Answer 5

subcutaneous tissue

Question 6

in terms of mechanoreceptors, what are the rapidly adapting mechanoreceptors?

Answer 6

meissner’s corpuscle and the hair follicle receptor

Question 7

what layer of the skin would you find the the meissner’s corpuscle and the hair follicle receptors?

Answer 7

the meissner’s corpuscle is found in non hair skin in the dermis layer

the hair follicle is found in the hair skin of the dermis layer

Question 8

in terms of mechanoreceptors what are the slowly adapting mechanoreceptors?

Answer 8

ruffini’s corpuscle, merkel’s receptors, and tactile mechanoreceptors

Question 9

what layer of the skin would you find the ruffini’s corpuscle, merkel’s receptors, and tactile mechanoreceptors?

Answer 9

ruffini’s corpuscle- hair skin in the dermis layer

merkel’s receptors- nonhairy skin in the dermis layer

tactile mechanoreceptors- hairy skin in the epidermis

Question 10

what are the fastest, quickest adapting, type of receptor

Answer 10

pacinian corpuscle

Question 11

what happens when you have more receptor potential rising above the threshold?

Answer 11

the greater becomes the action potential frequency and more nt’s released

Question 12

T/F, All sensory receptors adapt either partially or completely to any constant stimulus after a period of time?

Answer 12

T; keep in mind anything coming from the muscle and golgi spindles do not adapt, if we keep doing same movement, frequency is decreased but will not adapt to information and constant communication with the CNS is maintained so that movements are always being measured and initiated as necessary

Question 13

at what temperatures do warmth receptors operate?

Answer 13

begin firing above about 30°C and increase their firing rate until 44°C to 46°C

beyond 46°C, the rate falls off steeply and a sensation of pain begins

Question 14

at what temperatures do cold receptors operate?

Answer 14

steady discharge rate increases as the temperature falls to 24°C to 28°C

Below 10°C, firing ceases and cold becomes a very effective local anesthetic

Question 15

what is two point discrimination?

Answer 15

deals with the receptive field of the pacinian corpuscles and meissner’s corpuscles

pacinian corpuscles - receptors sense over a large area, you cannot discriminate between sense of touches because the sense is converge by the time it gets to cerebral cortex

meissner’s corpuscles - several located in one area and so discrimination between touches is greater

Question 16

what is two point discrimination like across the skin?

Answer 16

small in value meaning high in sensing and higher in back and thigh because of larger area and so no real sensitivity in ability to discriminate

huge hands, big lips, big face but then tiny body and this is how humunculus sees the body based on sense of touch

Question 17

what are the primary, secondary, tertiary neurons in relation to the inhibitory circuitry for two point discrimination?

Answer 17

convergence of information from point of touch to the cerebral cortex from primary sensory to tertiary

Question 18

what is the result from the interaction of nociceptors?

Answer 18

“inflammatory soup” of substances released when tissue is damaged
Arachidonic acid, lipid metabolites, bradykinin, histamine, serotonin, prostaglandins, nerve growth factor

Question 19

what is Peripheral Sensitization?

Answer 19

Following a painful stimulus (cuts, scrapes, bruises), stimuli in the area of the injury that would ordinarily be perceived as slightly painful are perceived significantly more, i.e. - sunburn