Sensory Mechanisms Lec 4

Question 1

What are the two pathways of sensory mechanism?

Answer 1

Neuron stimulated > Action Potential

Epithelial cell stimulated > releases neurotransmitters to stimulate neuron > Action Potantial

Question 2

How is sufficient stimulus of sensory neuron achieved and where does it go afterward?

Answer 2

spatial and temporal summation

to CNS

Question 3

Strength of stimulation from a neuron can be seen in its_____________?

Answer 3

firing rate

Question 4

mechanoreceptors:

and examples

Answer 4

detects deformation of membrane from

stretch receptors

Question 5

Give on example of a stretch receptor

Answer 5

stomach (fullness), muscles (indicate whether to contract to counteract force)

Question 6

thermoreceptors

Answer 6

alter rate of action potential firing when temperature changes

helps w/ homeostasis

Question 7

nocirepctors

Answer 7

these are receptors that respond to extreme mechanical, thermal, or chemical stimulus

reflexive

Question 8

photoreceptors

Answer 8

(which area type of electromagnetic receptor)

REVERSED: action potential when dark

Question 9

how do hair cells and statocysts function

Answer 9

hair cells are bent (conformational change) that lead to mechanical opening of ion channels

statocysts are used in equilibrium organs (like the inner ear of humans). Statocyst is a small ball that mechanically influences hair cells depending on orietnation

Question 10

explain how hearing works

Answer 10

• conformational change of tympanic membrane due to vibrations from sound
• cause hair cells to move
• hair cells will bend and cause an excitatory release of neurotransmitters or could be inhibitory depending on direction
• signals from auditory nerve cells are sent to the auditory cortext

Question 11

explain pitch and volume

Answer 11

pitch is determined by the frequency of the sound waves which affects particular hair cells on a particular part of the cochlea

volume is the result of a great amplitude of the sounds wave which causes a greater conformation change, which releases more neurotransmitters in cells at that particular frequency

Question 12

normal deafness with age

Answer 12

stiffening of ossicles

Question 13

damage from loud noise

Answer 13

scarring of tympanum

Question 14

congenital

Answer 14

cochlear, nerve, brain

Question 15

what type of receptor is involved w/ vision?

Answer 15

photorecptors
(which area type of electromagnetic receptor)

REVERSED: action potential when dark

Question 16

electromagnetic receptors

Answer 16

can detect wide range of electromagnetism: UV light, visible light infrared, etc.

Question 17

cone perceives what?

Answer 17

colors

Question 18

rods perceives what?

Answer 18

light intensity (dark or light)

Question 19

what are the proteins involved with vision? How do they work?

Answer 19

Opsin and Rhodopsin

light causes conformation change: cis to trans, closes the Na+ channel and hyperpolarizes cell

Question 20

senses involved with chemoreceptors

Answer 20

smell, taste, pheremones

Question 21

vomeronasal organ

Answer 21

detects pheremons

mating, aggression, behavior (two mice fighting)