Sensory Nerves Flashcards

1
Q

What is sensory modality?

A

The type of stimulus a receptor normally responds to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are mechanoreceptors?

A

Sensory receptors that are stimulated by mechanical stimuli - touch stretch, pressure, deformation.
Detect many stimuli, balance hearing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are proprioceptors?

A

Mechanoreceptors in joints and muscles that signal information information related to body or limb position.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are nociceptors?

A

Respond to painful stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a graded membrane potential change called in a sensory nerve?

A

Receptor potential or a generator potential

Transduction always results in the opening or closing of ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where are action potentials produced from the receptor potential?

A

Wherever the membrane has voltage gated ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When do you get a higher frequency of action potentials?

A

When there is a larger stimulus since this causes a larger receptor potential, can also activate more receptors too

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is meant by adaptation of a mechanoreceptor?

A

When the mechanoreceptor adapts to a maintained stimulus and only signals change or a novel event

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give an example of a sensory receptor that does not adapt?

A

Nociceptor, because it is important not o ignore a painful stimuli.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a pacinian corpsucle responsive to?

A

Vibration and pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the structure of a pacinian corpsucle

A

Myelinated nerve, naked nerve ending. The nerve ending is enclosed in a connective tissue capsule. This capsule contains layered membrane lamellae separated by fluid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How are action potentials generated from a pacinian corpsucle

A

Mechanical stimuli deforms the capsule and nerve ending, causing ion channels to open, - generator potential and then action potential.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is the pacinian corpsucle capable of rapid adaptation?

A

Fluid redistribution of corpsucle rapidly dissipates stimulus, nerve ending no longer stretched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens to the pacinian corpsucle when the stimulus is withdrawn?

A

Capsule springs back - more action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What type of structure os the pacinian corpsucle?

A

Non-neural accessory structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the receptive field?

A

The area that a stimuli will activate a sensory neurone

17
Q

What does the ability to tell apart two points on the skin depend on?

A

The size of the receptive field and neuronal convergence

18
Q

What is meant by convergence?

A

When multiple presynaptic neurones synapse with fewer post synaptic neurones

19
Q

What does convergence allow?

A

Allows sub threshold stimuli to sum at the secondary neurone forming and initiating action potentials

20
Q

How can we locate a stimulus so precisely?

A

Lateral inhibition of sensory neurones that are at the edge of the stimulus