Brainscape's Knowledge GenomeTM

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


See full index

Neurosciences > Exam2Lec2CutaneousSensation,Touch,andPain > Flashcards

Exam2Lec2CutaneousSensation,Touch,andPain Flashcards

1
Q

What is the somatosensory system?

A

A network of neurons that help humans recognize objects, discriminate textures, generate sensory-motor feedback and exchange social cues

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

Somatosensory receptors are what?

A

free nerve endings (no synaptic terminus, not myelinated)

sensation that they process is based on the shape of the receptor/protein at the receptive end of neurons

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

Nociception vs pain

A

Nociception is peripheral stimulation tellingus this can cause damge
pain is cognitive: no pain receptos; the brain motivates us to move away from damage

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

For modality Mechanoreception, Merkel cell receptor, what is the fiber type and role in perception and adaptation type?

A

Fiber type: AB
Role in perception: pressure, form, texture
adaptation type: slow

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

For modality Mechanoreception, Meissner corpuscle receptor, what is the fiber type and role in perception, and adaptation type?

A

Fiber type: AB
Role in perception: flutter, motion
adaptation type: rapid

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

For modality Mechanoreception, Ruffni corpuscle receptor, what is the fiber type and role in perception, and adaptation type?

A

Fiber type: AB
Role in perception: stretch
adaptation type: slow

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

For modality Mechanoreception, Pacinian corpuscle receptor, what is the fiber type and role in perception and adaptation type?

A

Fiber type: AB
Role in perception: vibration
adaptation type: rapid

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

For modality Mechanoreception, free nerve ending receptor, what is the fiber type and role in perception?

A

Fiber type: C
Role in perception: pressure

unmyelinated

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

For modality thermoreception, free nerve ending receptors, what is the fiber type and role in perception?

A

Fiber type: C and AY
Role in perception: C-> Warmth alpha delta->cold

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

For modality nociception, with the submodality SMALL, MYELINATED what is the receptor, fiber type and role in perception?

A

receptor: free nerve ending
Fiber type: alpha delta
Role in perception: sharp localized pain

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

For modality nociception, with the submodality UNMYELINATED what is the receptor, fiber type and role in perception?

A

receptor: free nerve ending
Fiber type: C
Role in perception: Burning

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

Mechanoreceptors are responsible for what?

A

Discriminative touch

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

What two layers do we have for mechanoreceptors?

A

Superficial layers and deeper layers

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

What type of receptors can we find on the superficial layers of mechanoreceptors?

A
  • Meissner corpuscle: flutter, motion, more “general” touch and superficial pressure on skin
  • Merkel disks: Pressure, form, texture, identification of “edges and stripes and shapes”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What type of receptors can we find on the deeper layers of mechanoreceptors?

A
  • Ruffini corpuscle: stretch
  • Pacinian corpuscle: deep pressure and vibration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is receptive field?

A

An area of skin that when stimulated with an adequate stimulus, will cause a specific neuron to alter its activity, may vary in size

a stimulis to which a receptor is most sensitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The highest density of neurons is where?

A

Index finger, palms of hands, and thumbs

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

What is two point discrimination?

A

The ability to discern that 2 nearby objects are truly 2 distinct points not one.

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

The ____ the receptive field, the more we are able to distinguish between sensations

A

SMALLER

the back, limb,s etc have a much higher threshold to discriminate 2 sep points

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

Explain cutaneous sensory transduction

A
  1. When skin is stretched, the membrane of the cell is stretched
  2. Ion channels open, get ion influx and can reach threshold generating an ap
  3. this then goes to neurons

channel stretches (mechano) and influx of ions occur
cutaneous receptors transduce degrees of skin deformation (stretch) or thermal energy

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

Receptors produce a generator potential through?

A

voltage or ligand gated ion channels

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

What do receptor code?

A
  1. Spatial location
  2. modality
  3. stimulation duration
  4. intensity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Perception of texture and pattern is a function of what two things?

A

Both rapidly and slowly adapting receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are slow adapting receptors? And what they help us detect?

A

merkel disks and ruffini’s ending
helps us detect place and duration

keeps firing , respinds over course of stimulius
ex: holding on to a cup of water to maintain muscle control or holding on during tug of war

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are rapidly adapting receptors? and what does it help us detect?

A

Meissner corpuscle and Pacianian corpuscle
Helps us detect changes in form

rapidly responds to changes in stimulus. Gages what is not impt once the stimulus has been noticed
ex: putting on clothes and not sensing that you have clothes on for the rest of the day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Somatosensory info enters the CNS via what structure?

A

Via the dorsal root ganglia into the dorsal root

this is outside sc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Once somatosensory info enters the spinal cord, the sensory fibers carrying touch, pressure, and vibration (mechanosensory) info travel up where?

A

Posterior/dorsal column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Once somatosensory info enters the spinal cord, the sensory fibers pain and temp info travel up where?

A

Lateral column

remeber it crosses anterolaterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where do large myelinated fibers bifurcate?

A

At the dorsal root entry zone
one branch ascends in the posterior (dorsal) columns
the other branches synapses in deepr laminae of the sc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Where do small, myelinated fibers synapse?

A

In the dorsal horn of the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Explain the dorsal column system for the lower body

A
  1. Mechnosensory information from the lower body enters the CNS at the lumbar spinal cord and travels up the gracile tract to the gracile nucleus in the caudal medulla.
  2. From there, same as upper body, it will CROSS at the internal arcuate fibers in the caudal medulla to continue traveling up on the opposite side. This crossing is known as DESCUSSATION.
  3. AFTER the internal arcuate fibers decussate, they form the medial lemniscus tract which travels up to the ventral posterior LATERAL nucleus of the thalamus (VPLN).
  4. Then it goes to primary and secondary somatosesnory cortex to integrate info.

Ventral Posterior (L)ATERAL
Nucleus = (L)otion for the BODY

32
Q

Explain the dorsal column system for the upper body

A
  1. Mechnosensory information from the upper body enters the CNS at the cervical spinal cord and travels up the cuneate tract to the cuneate nucleus in the caudal medulla.
  2. From there, same as lower body, it will CROSS at the internal arcuate fibers in the caudal medulla to continue traveling up on the opposite side. This crossing is known as DESCUSSATION.
  3. AFTER the internal arcuate fibers decussate, they form the medial lemniscus tract which travels up to the ventral posterior LATERAL nucleus of the thalamus (VPLN).
  4. Then it goes to primary and secondary somatosesnory cortex to integrate info

Ventral Posterior (L)ATERAL
Nucleus = (L)otion for the BODY

33
Q

If there is a LEFT spinal injury, which side of the body would loose mechanosensation?

A

left

34
Q

If there is a RIGHT brainstem injury, which side of the body would lose mechosensation?

A

left

35
Q

Explain the trigemino-thalamic-cortical pathway

A
  1. Mechanosensory information from the FACE enters the brainstem directly via the trigeminal ganglion and synapses in the principal trigeminal nucleus of the caudal medulla.
  2. Fibers immediately cross the midline and ascend via the trigeminal lemniscus to the ventral posterior MEDIAL nucleus of the thalamus.
  3. Then it goes to primary and secondary somatosesnory cortex to integrate info

Ventral Posterior (M)EDIAL
Nucleus = (M)akeup for the FACE

36
Q

What are dermatomes?

A

Slice of skin that 1 spinal root or one brainstem CN roots carries info from. Helps clinically to localize things

there are 3 dermatomes in face inn by trig nerve

37
Q

Where do we integrate different kind of touch info?

A

primary somatosensory cortex

38
Q

Why do we have so many layers of the primary somatosensory cortex?

A

B/c we need to to driciminate touch coming in pain, proprioception, and more and we start integrating info and send it out for response.

39
Q

What uses up the largest area of the ventral posterior complex (VPM; medial) and the somatosensory cortex and why?

A

The face uses up the largest area b/c a large density of information coming from a large number of neurons with small receptive fields.

40
Q

What uses a smaller portion of the ventral posterior complex (VPL; lateral) and the somatosensory cortex?

A

thoracic region of the body

41
Q

What region of the spinal cord takes up the biggest processing area in thalamus and somatosensory cortex?

A

cervical

42
Q

What determines how big the nuceli are?

A

The density of info NOT amt of body they are responding to

43
Q

At the level of somatosensory cortex, what structure do we have that represents how much brain processing there is for each body part?

A

homunculus

44
Q

A tiny amt of skin in hand has the biggest area of processing , why?

A

It is b/c this is what we use for identification, it has a high density info and small receptive field

45
Q

Explain somatosensory plasticity and give an example

A

It has lots of ability to change in response to stimuli that are coming in.
ex: amputate 3rd finger, the somatosensory complex does not create any dead or wasted space, it starts responding to neighboring neurons that are still sending input by using there processing space and you become more sensitive in other fingers

another example: learning to play piano at a young age, 2 fingers grow in plasticity and allocate more brain procesing space to play instrument

46
Q

Do we have pain receptors?

A

NO, nociceptors respond to very
intense and possibly harmful stimuli

only conscoius perception

47
Q

What is the role of thermoreceptors?

A

Responds to heat up until a certain threshold then nociceptors kicks in

48
Q

What is the role of nociceptors?

A

responds to intense stimuli that can cause tissue damage

49
Q

Aδ fibers perceives ____ pain type

A

acute, sharp, sting

cold

50
Q

C fibers perceive ____ pain type

A

dull, long lasting

warmth

51
Q

Are most Aδ fibers and C fibers nociceptors?

A

yes

52
Q

Free nerve ending of Aδ fibers are excitatory or inhibitory?

A

Excitatatory amino acids (glut, aspartate, ATP)

53
Q

What is capsaicin?

A

Capsaicin binds to an allosteric binding site on a vanilloid receptor** (VR-1)**. Allowing ion influx

capsaicin, acid, heat all open vr-1 recept. Lvls of capsaicin determines how much you like spicy food

54
Q

Mechnoreceptive information enters the spinal cord via the dorsal horn and travels up the posterior/dorsal on which side?

A

ipsilaterally (same side), it will not cross until it reaches the brainstem.

55
Q

Nociceptive information, on the other hand, will enter the spinal cord via the dorsal horn on which side via what structure?

A

Cross to the lateral side immediately via the anterior white commissure.

55
Q

If you have a right sc lesion which side do we lose discriminatory touch and pain/temp perception?

A

Lose discriminatory touch on right side lose response to pain and temp on left side.

55
Q

If you have a left sc lesion which side do we lose discriminatory touch and pain/temp perception?

A

Lose discrimiantory touch if the left side and pain/temp perception on the right side

56
Q

What is the difference b/w ant. commisure and ant. white commissure?

A

ant commisure: small bundle of fibers connecting the 2 hemispheres

ant white commisure: this is in the sc, and this is where pain signals enters sc and crosses immediately

57
Q

After pain signal crosses immediately at the ant white commissure, it travels through the ____ tract.

A

anterolateral

nociceptor-> enters dorsal root ganglia->deccusate immediate at ant white commissure-> up through ant lat tract of sc-> up into the brain

58
Q

What is lissauer’s tract?

A

redundency crossing of nociceptor info @ multiple spinal roots 2-3 segments above and below dorsal root entry zone. Helps us maintain nociptive info

pain info does not come in at 1 spinal root, it comes in and crosses at multiple layers.

59
Q

If you have a small sc lesion, at one spinal root, can you still get nociceptive info? Why or why not?

A

Yes you still get nociceptive info b/c it will cross @ another lvl (redudant)

60
Q

Explain the anterolateral tract (neospinothalamic)

A
  1. Nociceptive information from BOTH the upper and lower body enters the CNS via the dorsal root ganglion and IMMEDIATLEY CROSSES at the anterior white commissure to the anterolateral portion of the spinal cord.
  2. From there, nociceptive information travels up the spinothalamic/neospinothalamic tract to the ventral posterior LATERAL nucleus of the thalamus.
  3. Finally, the fibers ascend to the primary (SI) and secondary (SII) somatosensory cortex where we begin integrating somatosensory information.

pain!

60
Q

Explain the trigeminal system

A
  1. Nociceptive information enters the CNS at the pons.
  2. From there it will travel DOWN to the medulla,
  3. From there, nociceptive information travels up the trigemino-thalamic tract to the ventral posterior MEDIAL nucleus of the thalamus.
  4. Then it goes to primary and secondary somatosesnory cortex to integrate info
60
Q

If you injury the medulla on the left side, where do you lose pain info on your face?

A

Both sides of your face, your whole face!

Injury to the medulla will lead to loss of nociception on both sides of the face.

61
Q

Nociceptive pathway goes through entire ____ system to get away from painful stimulus now. and avoid in the future

A

limbic

has memory and emotional component

62
Q

What are diff targets of the anterolat system?

A
  1. Anterior Cingulate/Insular cortex: Avoidance/emotional component that drive behavioral responses
  2. Amygdala: negative emotion
  3. Hypothalamus: fight or flight
  4. Superior colliculus: directs our attention to the source of pain
  5. Reticular formation: arousal (via release of acetylcholine) in order to respond to pain
  6. Periaqueductal Gray: pain control
63
Q

What is referred pain?

A

It is when someone has somatosensory pain and it feels superficial/external but is actually pain from an organ

ex: heart attack (shoulder or arm pain)

64
Q

What does allodynia mean?

A

perception of normally
non-nociceptive stimuli as being
painful

something that shouldn’t be painful, but is

ex:you have a sunburn, you put clothes , it hurts

65
Q

What is hyperalgesia?

A

nociceptive stimuli
perceived as being more painful
than expected

feel worse than normal

ex: you have a sunburn, and someone slaps you on where your sunburn is

66
Q

What is peripheral sensitization?

A

when you get allodynia
and/or hyperalgesia due to
peripheral mechanisms

ex: more histamine circulation

67
Q

What is central sensitization?

A

allodynia
and/or hyperalgesia due to central
mechanisms

perception is exagerrated due to trauma/previous experience

68
Q

Explain the peripheral sensitiztion inflamatory response/ axon reflex

A
  1. Trauma initiates inflammatory response which activates C fibers.
  2. This causes the release of neuropeptides (substance P, glutamate, etc.
  3. Now there is local sensitization around the site of the injury
69
Q

Explain central sensitization

A

Neurochemistry
* Sensitization of NMDA receptors on spinal interneurons or directly on anterolateral tract neurons alters synaptic efficacy
Anatomic reorganization in spinal cord
* Loss of primary afferents results in sprouting of existing afferents in dorsal horn

70
Q

Explain descending pain modulation

with the periaq gray

A
  1. Spinotectal fibers synapse in the periaqueductal grey (PAG) which projects to:
    * Raphe nucleus: serotonergic projections
    * Lateral Tegmental Nucleus: noradrenergic projections
  2. These projections synapse on
    enkephalinergic interneurons in the dorsal horn

pag releases serotonin and norepi and goes back down to reduce signaling at the lvl of the sc where inj occured and release enkepheline (reduce pain signal in nerv system)

71
Q

Explain pain control in the spinal column

A
  1. You have serotonin and norepi (input coming from raphe nuclei and tegmental ) coming down
  2. this activates and releases enkephalin neuron at the sc
  3. this inhibits the C fiber (nocipetor) from synpasing onto the dorsal horn projection neuron to anterolat system
72
Q

Explain phantom limb loosly

A

It is when you loose a peripheral body, but you feel like you still have that limb. Trigger points are going to become those areas of skin that were processed proximally as somatosensory cortex

ex: loss one arm, some response in areas of face and shoulder

Neurosciences (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions