Somatosensory Systems

Question 1

cells within the receptor organ that can detect and convert a particular stimulus into a neural impulse are called ______ _______

Answer 1

receptor cells

Question 2

list 5 types of stimulus

Answer 2

• temperature
• light
• chemicals
• sound
• mechanical pressure

Question 3

what is sensory transduction?

Answer 3

converting stimulus energy into a change in membrane potential and possibly a neural impulse

Question 4

What is receptor potential?

Answer 4

a local change in the membrane potential of a receptor cell that occurs in response to a sensory stimulus (Like ESPS except it’s occurring due to sensory stimulus)

Question 5

How does the brain differentiate between types of stimuli?

Answer 5

stimulus type can be coded by label lines

Question 6

particular neurons that are labeled for distinctive sensory input are called ______ ______. There is different receptors with different neural tracts from each other and this creates different ______ _________.

Answer 6

• label lines
• sensory experiences

Question 7

stimulus intensity can be coded in the frequency of _____ _______ generated within a neuron

Answer 7

action potentials

Question 8

what is adaptation

Answer 8

it is when the stimulus is unchanging, which results in fewer action potentials happening, allowing you to notice changes and not be overstimulated.

Question 9

stimulus location can be coded by using _____ ______. Why is this?

Answer 9

• label lines
• because it is able to tell the different stimulus apart from each other

Question 10

The stimulus region that affects the activity of a neuron in the sensory system is called ______ _______

Answer 10

receptive field

Question 11

neurons that respond to more than one stimulus modality are called ______

Answer 11

polymodal

Question 12

When a stimulus from one modality sometimes evokes a perception from another modality this is called ____. An example of this is:

Answer 12

• synesthesia
• days of the week in different colors

Question 13

When it comes to unipolar neurons, instead of calling them dendrites we call them ____ _______

Answer 13

nerve endings

Question 14

Mechanically gated Na+ channels

Answer 14

• located in the skin receptors
• critical for sense of touch
• channel opens by the nerve membrane being pulled open, which results in a depolarization and action potential

Question 15

What are the 4 types of touch receptors?

Answer 15

1. Pacinian corpuscle
2. Meissner’s corpuscle
3. Merkel’s discs
4. Rufini’s ending

Question 16

Pacinian corpuscle

Answer 16

large, vague border touch receptor that feels deep pressure and vibrations

Question 17

When it comes to touch, you generate vibrations when you feel ___________

Answer 17

textures

Question 18

Meissner’s corpuscle

Answer 18

small, sharp border touch receptors that feel fine touch and vibrations

Question 19

Merkel’s Disc

Answer 19

located closest to the surface of the skin, these receptors feel fine touch, points, and edges

Question 20

Ruffini’s ending

Answer 20

large receptive fields, big events of skin stretch, like moving limbs

Question 21

What is the pathway in which sensory information is sent to the brain?

Answer 21

1)Information about touch stimuli travels to the brain via the dorsal columns
2) Axons from the dorsal columns project to the medulla. The medullar neurons project to the thalamus. The thalamic neurons send this information to the somatosensory cortex.
3) The somatosensory cortex (S1, post-central gyrus) is organized into a topographic fashion.

Question 22

Discuss the concept of plasticity in the somatosensory cortex

Answer 22

It can change internal organization so that the response properties of neurons in the cortex are altered. An example is when someone has a hand amputated, the brain will have other body part senses take over the area of the brain originally responsible for hand senses.

Question 23

Receptor potentials can best be described as:

Answer 23

proportional to stimulus intensity

Question 24

The area within which a stimulus results in a change in the activity of a neuron in a sensory pathway is the ____ _____ of the neuron.

Answer 24

receptive field