Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

321 - Physiology > Lecture 2 - Somatosensation > Flashcards

Lecture 2 - Somatosensation Flashcards

1
Q

What is the somatosensory system responsible for?

A

Touch

Proprioception

Temperature

Pain

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

Where do somatosensory afferents synapse?

A

Spinal cord or brain (in the cranial nerves)

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

What does it mean if a receptor is fast-adapting (phasic)?

A

The firing stops quickly as the stimulus continues, but reacts strongly when a stimulus is changing

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

What is another name for slow-acting receptors?

A

Tonic receptors

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

If a receptor has a small receptive field, what is easier to distinguish?

A

Greater acuity in distinguishing between two points of stimuli

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

What is lateral inhibition?

A

Signals from neurons at the center of the receptive field inhibit neurons on the periphery

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

If the intensity of a stimulus is increased, how will the firing of the action potentials be affected?

A

There will be an increased number of action potentials

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

What are 1st order neurons?

A

Afferent (sensory) neurons

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

What are 2nd order neurons?

A

Neurons in the spinal cord or brain stem

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

What are 3rd order neurons?

A

Neurons in the thalamus

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

What are 4th order neurons?

A

Neurons in the primary area of the cortex

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

What are A(alpha) fibers?

A

Largest and fastest sensory neuron; most myelinated. Proprioceptors of skeletal muscle.

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

What are A(beta) fibers?

A

The second fastest and second most myelinated axons. Mechanoreceptors of skin

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

What are A(delta) fibers?

A

Smaller axons but still have myelination. Pain and temperature

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

What are C fibers?

A

The smallest axon, no myelination. Temperature, pain, itch

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

What are the 4 types of mechanoreceptors?

A
  1. Merkel’s Disk
  2. Meissner’s Corpuscle
  3. Ruffini’s Corpuscle
  4. Pacinian Corpuscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Can a slow-adapting receptor ever adapt to a stimulus?

A

Yes, over time the continuous pressure being sensed will become adapted to. (ex wearing a watch)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What type of touch do Merkel’s disks sense?

A

Light touch/pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the characteristics of Merkel’s disks?

A

-Located in epidermis (superficial)
-Small receptive field
-Most receptive/sensitive
-Slow adapting*
-A(beta) fiber
-Releases neurotransmitters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What type of touch do Meissner’s Corpuscles sense?

A

Light touch and movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the characteristics of Meissner’s Corpuscles?

A

-Located in epidermis (superficial)
-Small receptive field
-Fast adapting*
-A(beta) fiber
-Uses Na+ to trigger action potentials instead of neurotransmitters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What type of touch do Ruffini’s Corpuscles sense?

A

Stretch and skin tension. Position and movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the characteristics of Ruffini’s Corpuscles?

A

-Parallel to the skin in the dermis
-Large receptive field
-Slow adapting
-Uses Na+ to trigger action potential

24
Q

What type of touch do Pacinian Corpuscles sense?

A

Pressure and deep touch

25
Q

What are the characteristics of Pacinian Corpuscles?

A

-Located in subcutaneous tissue
-Large receptive field
-Fast adapting

26
Q

What is the most abundant type of receptor in the skin?

A

Free nerve endings (pain and temperature)

27
Q

How do Pacinian Corpuscles trigger an action potential?

A

Mechanical pressure distorts the outer layers, causing internal stretch receptors to open Na+ channels. This leads to a graded potential which if large enough, will trigger an action potential.

28
Q

Which type of receptor will recognize fine details of Braille?

A

Merkel’s Disks

29
Q

What do proprioceptors do?

A

Provide details on position of limbs in space

30
Q

What are the two types of proprioceptors?

A
  1. Muscle spindles
  2. Golgi tendon organs
31
Q

Where are muscle spindles located and what do they do?

A

-Located in skeletal muscle

-Signal changes in muscle length (stretch receptors)

32
Q

Where are golgi tendon organs located and what do they do?

A

-Located within tendons

-Detects amount of tension that muscle exerts on tendons. Can also activate to decrease muscle contraction and force during overload

33
Q

What type of fiber is responsible for proprioception?

A

A(alpha) fiber

34
Q

What type of fiber is responsible for mechanoreception?

A

A(beta) fiber

35
Q

What is the Dorsal Column-Medial Lemniscus Pathway (DCML)?

A

A pathway from the spinal cord to the cerebral cortex. Carries fine touch, pressure and proprioceptive sensations

36
Q

Info from the upper limb ascends within the___________?

A

Fasciculus cuneatus

37
Q

Info from the lower limb ascends within the___________?

A

Fasciculus gracilis

38
Q

What is processed by the somatosensory cortex?

A

Localization of touch and intensity

39
Q

If an area has a greater sensory receptor innervation, what will the corresponding area of the somatosensory cortex be like?

A

It will be a larger area of the cortex

40
Q

What is thought to be an adaption to nocturnal life in mice and rats?

A

The barrel cortex, which is a topographic map of each whisker

41
Q

What are the characteristics of thermoreceptors?

A

-Free nerve endings
-A(delta) and C fibers
-Fast adapting to constant temp
-Warm and cold thermoreceptors

42
Q

What is the range of temperature where pain receptors would be activated if exceeded?

A

Temperatures below 15C or above 43C

43
Q

What are TRP channels?

A

Transient receptor potential channels

–> triggered at a certain temp will cause an influx of Na+ and Ca2+

44
Q

What receptor do avians have a mutation in that allows them to be resistant to capsaicin (spicy)?

A

TRPV1 receptor

45
Q

Are Merkel’s discs slow or fast adapting?

A

Slow

46
Q

How big is the receptive field of Merkel’s discs?

A

Small

47
Q

Which mechanoreceptors are responsible for tactile acquity?

A

Merkel’s discs

48
Q

Are Meissner’s corpuscles slow or fast adapting?

A

Fast

49
Q

How big is the receptive field of Meissner’s corpuscles?

A

Small

50
Q

Which mechanoreceptor detects vibration?

A

Meissner’s corpuscles

51
Q

What percentage of the sensory innervation in the hand is due to Meissner’s corpuscles?

A

40%

52
Q

How big is the receptive field of Ruffini’s corpuscles?

A

Large

53
Q

Are Ruffini’s corpuscles slow or fast adapting?

A

Slow

54
Q

Are Pacinian corpuscles slow or fast adapting?

A

Fast

55
Q

How big is the receptive field of Pacinian corpuscles?

A

Large

321 - Physiology (52 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions