Intro to Senses

Question 0

Define transducer.
How many stimuli can it respond to?
Where are they located?

Answer 0

transducers are specialized receptor cells. They reside in sensory receptor organs such as the cochlea and only respond to one stimulus.

Question 1

Transduction

Answer 1

The translation of info in the environment into a signal the brain can understand

Question 2

Explain doctrine of specific nerve energies.

Who proposed this?

Answer 2

States that receptors and neural channels for different senses are independent. Stated that only one sensation is produced and that each uses different nerve energies.

Question 3

Labeled Lines. Explain this BITCH.

Answer 3

Labeled lines is the current concept that includes action potentials traveling from sensory receptors along different nerve tracts to the brain. The different “lines” allow for perceptual differences. Also, neurons are specialized for each sense.

Question 4

nociceptor

Answer 4

May not respond to one type of energy.

Rather, responds to magnitude of energy large enough to cause tissue damage. Related to sensation of pain.

Question 5

What do bare nerve endings respond to?

Answer 5

Pain, temp

Question 6

What type of receptors have encapsulated endings?

Answer 6

Mechanoreceptors such as pacinian and meissners

Question 7

Name some specialized cells

Answer 7

olfactory, rod, cone, vestibular, auditory, taste

Question 8

Describe transduction through generator potentials.

Answer 8

Generator potentials are are the graded, decementally spread, slow, local depolarizations that eventually lead to action potential if threshold is reached.

Question 9

synonym for generator potential

Answer 9

receptor potential

Question 10

Give the order of transduction from incoming energy to action potential

Answer 10

stimulus > generator potential > action potential

i.e. vibration causes deformation of pacinian corpuscle > generator potentials occur as mechanically gate ion channels open > threshold reached > action potential

Question 11

contrast sensory experience vs action potential

Answer 11

action potentials are all or nothing, but sensory experiences are not. Frequency of action potentials is proportional to generator potential amplitude and therefore stimulus intensity

Question 12

What is the purpose of receptive fields

Answer 12

to allow precise localization of stimulus. Cells can be selective to react to small or large stimuli by the size of their threshold

Question 13

facts about receptive fields

Answer 13

All sense have receptive fields
the smaller the receptive field, the more precise the info sent to brain
Some receptive fields are excitatory in the middle and inhibitory surround. or vice versa. This allows for detection of lines\discontinuities

Question 14

Tactile corpuscle: synonym and what does it respond to

Answer 14

meissners corpuscle, responds to light touch. its phasic

Question 15

name for tonic tactile corpuscles

Answer 15

merkle’s

Question 16

What do free nerve endings respond to

Answer 16

pain and temp

Question 17

Lamellated corpuscle. name and stimulus

Answer 17

Pacinian, vibration

Question 18

What does the ruffini corpuscle respond to

Answer 18

deep pressure

Question 19

Need to look at:

Answer 19

homunculus, innervation of pacinian corpuscle, peripheral mediation of pain, major classes of somatic sensory receptors

Question 20

Describe large myelinated axons

Answer 20

Fast transmission and mechanosensation

Question 21

describe samll myelinated axons

Answer 21

moderate speed

pain, temp, mechanosensation

Question 22

describe unmyelinated axons

Answer 22

slow

pain, temp, crude mechanosensation, visceral

Question 23

adaption

Answer 23

receptors tend to slow discharge with time when stimulus doesnt change. Even though the stimulus is constant, the generator potential decreases and action potential frequency decreases as a result=