Overview of Sensory Systems and Receptors

Question 1

What are Aδ fibers?

Answer 1

• 1-5 micrometers in diameter
• 4-30 m/sec
• sharp pain, cold temperature

Question 2

Name the fiber type:

• small, unmyelinated axons
• 1 micrometer in diameter
• average conduction velocity of 0.4-2 m/s
• info about warm temperature, burning pain, itch, crude touch

Answer 2

C fibers

Question 3

Some receptors, such as hair cells of the auditory system, respond to stimulation with ______.

Answer 3

an oscillatory change

Question 4

What do muscle mechanoreceptors fire in response to?

Answer 4

stretch

Question 5

Give 2 examples of a long sensory receptor.

Answer 5

1. the somatosensory receptor cell
2. skin mechanoreceptors

Question 6

Name the fiber type:

• 5-10 micrometers in diameter
• 30-60 m/sec
• mechanoreceptors of the skin

Answer 6

Aβ fibers

Question 7

Give 6 examples of sensory modalities.

Answer 7

1. vision
2. hearing
3. smell
4. taste
5. touch
6. thermoreception

Question 8

What are C fibers?

Answer 8

• small, unmyelinated axons
• 1 micrometer in diameter
• average conduction velocity of 0.4-2 m/s
• info about warm temperature, burning pain, itch, crude touch

Question 9

What are the 5 attributes of a stimulus that sensory systems convey?

Answer 9

1. modality
2. intensity
3. quality
4. duration/frequency
5. location

Question 10

Auditory information is relayed through the _____ to the auditory cortex in the temporal lobe.

Answer 10

medial geniculate nucleus (MGN)

Question 11

What is the role of the sensory receptor cell?

Answer 11

to convert one type of physical energy into a change in membrane potential and to transmit this information to a 2nd order nerve cell

Question 12

Cells that hyperpolarize in response to stimulation have resting potentials that lie btw ____ and ____, generally _____.

Answer 12

0 and -70mV; typically -30 to -40 mV

Question 13

What are the 3 main functions of sensory information?

Answer 13

1. conscious sensation
2. control of mvmt
3. maintaining arousal

Question 14

In receptor cells that respond to stimuli by hyperpolarization, increased stimuli intensity will cause the cell to _____.

Answer 14

become more hyperpolarized

Question 15

Visual information is relayed through the lateral geniculate nucleus (LGN) of the thalamus to the _____.

Answer 15

visual cortex in the occipital lobe

Question 16

Conscious appreciation of sensory modalities is determined by specific neuronal connections from sensory organs through the ____ to the _____.

Answer 16

thalamus; cerebral cortex

Question 17

What kind of protein is rhodopsin?

Answer 17

a GPCR (7 transmembrane segments)

Question 18

In ______ receptor cells (less than 0.1mm to 100 micrometers in length), the receptor potential spreads to the synaptic end of the cell by passive electronic transmission.

Answer 18

short sensory

Question 19

What is the concept of labeled lines?

Answer 19

conscious appreciation of a sensory modality is determined by the specific neuronal connections from sensory organs through the thalamus to the cerebral cortex

Question 20

Increased conductance in the receptor causes the membrane potential to ____.

Answer 20

move towards 0mV

Question 21

What does metarhodopsin do?

Answer 21

it activates transducin

Question 22

Receptors that depolarize do so as a result of _____.

Answer 22

an increase in nonspecific cation conductance in the receptive area membrane

Question 23

Light causes rhodopsin to change into _____.

Answer 23

metarhodopsin

Question 24

Receptor potential increases in magnitude as the ______ of the stimulus increases.

Answer 24

intensity

Question 25

The selectivity of a receptor lies at the _____ level.

Answer 25

molecular

Question 26

What does transducin do?

Answer 26

it activates a cGMP phosphodiesterase enzyme leading to the breakdown of cGMP to guanosine

Question 27

In long sensory receptors (\_\_\_\_\_ in length), regenerative action potentials must be employed to carry info from the receptive ending to the synaptic release site.

Answer 27

greater than 0.1mm

Question 28

Visual information is relayed through the\_\_\_\_\_\_ of the thalamus to the visual cortex in the occipital lobe.

Answer 28

lateral geniculate nucleus (LGN)

Question 29

Receptor potential _____ in magnitude as the intensity of the stimulus \_\_\_\_\_\_.

Answer 29

increases; increases

Question 30

What is transduction?

Answer 30

the process of sensory input and transformation of info into a change in neuronal action potential

Question 31

What are Aβ fibers?

Answer 31

* 5-10 micrometers in diameter * 30-60 m/sec * mechanoreceptors of the skin

Question 32

Give 2 examples of short sensory receptors.

Answer 32

1. photoreceptor cells 2. auditory hair cells

Question 33

In short sensory receptor cells (\_\_\_\_\_ in length), the receptor potential spreads to the synaptic end of the cell by passive electronic transmission.

Answer 33

less than 0.1mm to 100 micrometers

Question 34

\_\_\_\_\_ information is relayed through the lateral geniculate nucleus (LGN) of the thalamus to the visual cortex in the occipital lobe.

Answer 34

Visual

Question 35

In short sensory receptor cells (less than 0.1mm to 100 micrometers in length), the receptor potential spreads to the synaptic end of the cell by \_\_\_\_\_.

Answer 35

passive electronic transmission

Question 36

What is the receptor protein in rod photoreceptors?

Answer 36

rhodopsin

Question 37

Name the fiber type: * 1-5 micrometers in diameter * 4-30 m/sec * sharp pain, cold temperature

Answer 37

Aδ

Question 38

What does decreased cGMP in the eye receptor do?

Answer 38

hyperpolarizes the photoreceptor cell --\> NT release

Question 39

Which sensory system is an exception in that it does not have to travel through the thalamus on the way to its brain destination?

Answer 39

the olfactory system

Question 40

In ______ receptors (greater than 0.1mm in length), regenerative action potentials must be employed to carry info from the receptive ending to the synaptic release site.

Answer 40

long sensory

Question 41

\_\_\_\_\_\_ information is relayed through the medial geniculate nucleus (MGN) to the auditory cortex in the temporal lobe.

Answer 41

Auditory

Question 42

Give an example of a receptor that hyperpolarizes upon stimulation.

Answer 42

rod photoreceptors

Question 43

In long sensory receptors (greater than 0.1mm in length), ______ must be employed to carry info from the receptive ending to the synaptic release site.

Answer 43

regenerative action potentials

Question 44

\_\_\_\_\_\_ increases in magnitude as the intensity of the stimulus increases.

Answer 44

Receptor potential

Question 45

Auditory information is relayed through the medial geniculate nucleus (MGN) to the \_\_\_\_\_\_.

Answer 45

auditory cortex in the temporal lobe