Module 5

Question 1

sensory receptors are

Answer 1

specialized cells that convert (transduce) sensory energy into neural activity

Question 2

somatosensory receptors transduce what energy

Answer 2

mechanical energy

Question 3

T/F the larger density of receptors in an area = greater sensitivity

Answer 3

true

Question 4

Neural relays allow sensory systems to

Answer 4

interact

Question 5

neural relay of visual receptors

Answer 5

visual receptor
thalamus
cerebral cortex

Question 6

We only sense between __ to__ nm of the electromagnetic spectrum

Answer 6

380-760

Question 7

the cornea is

Answer 7

clear outer layer

Question 8

iris is the

Answer 8

opens and closes to allow more/less light in
theres a hole in the iris (pupil)

Question 9

the lens is

Answer 9

focuses the light
bends to accommodate near and far objects

Question 10

the retinal is

Answer 10

where the light energy initiates neural relays

Question 11

rods vs cons

Answer 11

rods
- more abundant
- sensitive to low levels of light
- night vision mostly
- black/white

cones
- bright light
- specialized for colour and high visual acuity
- in FOVEA ONLY
- 3 kinds of pigments
- 419(blue - short wavelength)
- 531(green - medium wavelength)
- 559(red - long wavelength)

Question 12

Pacinian corpuscle is a skin receptor that provides a clear example of the process of

Answer 12

sensory transduction

reading braille

A stimulus to the corpuscle opens sodium channels and produces a graded generator potential.

Question 13

T/F Hair cells respond to mechanical distortion of vibrating fluid in ear.

Answer 13

true

Question 14

once stimuli is transduced, next is

Answer 14

perception (which is relative - subjective)

Question 15

Once the cell reaches the maximum firing rate what will happen??

Answer 15

no change in rate

Question 16

what is adaptation

Answer 16

the progressive loss of receptor sensitivity
as stimulation is maintained

Question 17

what are the benefits of adaption

Answer 17

1. Adaptation helps us to ignore constant, innocuous stimuli, reducing distraction.
2. Adaptation helps to avoid saturation of neuronal firing rates, allowing us to detect change in stimulus intensity over a larger range of intensities.

Question 18

Neuroscientists often distinguish two types of adapting receptors/cells

Answer 18

1.) Phasic receptors (generally adapt fast): display adaptation and decrease frequency of action potentials.
2.) Tonic receptors (generally slow adapting): show slow or no decline in action potential frequency.

Question 19

what is considered the language of the nervous system

Answer 19

action potentials

Question 20

action potentials are SO PREDICTABLE and always have the same

Answer 20

size and duration

Question 21

Touch is a great example of range __

Answer 21

fractionation

Question 22

There are several different qualitatively different sensory experiences like

Answer 22

pressure
vibration
tickle
smoothness
wetness

Question 23

T/F Within the sense of touch, each type of receptor (stretch, vibration, pain, touch) has a distinct set of sensory receptors, so different qualities of skin stimulation can be communicated to the brain

Answer 23

true

Question 24

Pain, heat, and cold stimuli are
detected by

Answer 24

free nerve endings
(often unmyelinated)

Question 25

Meissner’s corpuscles (also known as tactile corpuscles) and Merkel’s discs mediate most of our ability to perceive

Answer 25

form of objects we touch

Question 26

TWO-POINT THRESHOLD TEST

Answer 26

An approximate measure of the density and receptive field properties of touch receptor

Question 27

THE CONCEPT OF LABELED LINES

Answer 27

The concept that each nerve input to the brain reports only a specific type of information

Question 28

T/F Sensory information travels from the sensory surface to the highest levels of the brain.

Answer 28

true

Question 29

T/F The concept of labeled lines says that the brain recognizes distinct senses because action potentials travel along separate nerve tracts

Answer 29

true

Question 30

All somatosensory (touch) neurons form together close to the spinal cord to create ______.

Answer 30

dorsal root ganglion nerves

Question 31

The axons of dorsal root ganglion neurons are known as ___

Answer 31

afferents

Question 32

homunculus is

Answer 32

"little man" map (Penfield)

Question 33

the primary somatosensory cortex is located in the

Answer 33

postcentral gyrus in the parietal lobe

Question 34

In 1937 a Canadian neurosurgeon ____ stumbled upon the somatosensory regions of the brain…

Answer 34

Penfield