Somatosensory System Flashcards Preview

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Flashcards in Somatosensory System Deck (20)
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1
Q

What are the three types of axons?

A

A- beta
A-delta
C axons

2
Q

What is the conductance times for the 3 types of axons?

A

A beta: 35-75 m/s
A delta: 5-30 m/s
C: 0.5-2 m/s, unmyelinated

3
Q

What are each of the axons responsible for?

A

A beta: touch
A delta: pain temperature
C: pain, temperature

4
Q

What is the diameter of each of the axons?

A

A beta: 6-12 um
A delta: 1-5 um
C: 0.2 -1.5 um

5
Q

What is the DCML responsible for and where does it synapse?

A
  • responsible for touch, a beta axons

- synapse in the brainstem (medulla)

6
Q

What is the STT responsible for and what is the main difference between the STT and the DCML?

A
  • pain and temperature from C axons and a delta

- decussates

7
Q

What are the four part of the spinal cord?

A

Cervical
Thoracic
Lumbar
Sacral

8
Q

What are dermatomes?

A

areas of the skin that is mainly supplied by a single nerve cell

9
Q

What are the four types of receptor endings?

A
  1. Meissner Corpuscle
  2. Merkel Cell
  3. Ruffini Ending
  4. Panician Corpuscle
10
Q

What are the benefits of adaptation?

A
  • helps us to ignore constant stimuli reducing distractions

- allows us to detect changes in stimulus intensities over a larger range of intensities

11
Q

What is the cost of adaptation?

A

we can’t tell stimulus strength from firing rate

  • adaptation eliminates the baseline so you can identify change better but then you don’t know the baseline
    ex. putting a cup on a scale and clearing the weight of the cup so you get the weight of whats inside
12
Q

What part of the spinal cord does the DCML refer to?

A

dorsal

13
Q

What part of the spinal cord does the STT refer to?

A

ventral

14
Q

If the left side of the body’s sense of pain and temperature is affected, what system is affected, and what side of the spinal cord?

A

STT
right side because it decussates
ventral part

15
Q

What is a cold receptor?

A

a receptor that fires more action potentials in the cold

16
Q

What is a warm receptor?

A

a receptor that fires more action potentials in the warm

17
Q

how thick is the cortical column?

A

2 mm thick

18
Q

What percentage of the column is excitatory neurons and what percentage is inhibitory neurons? what are the other names for these neurons?

A

70 % excitatory or pyramidal

30% inhibitory or non pyramidal

19
Q

What do each of the individual layers do?

A

2-3: send axons to and receives axons from other cortical areas

4: receives axons from the thalamus
5: sends axons to the brainstem and spinal cord
6: sends axons to thalamus

20
Q

What is the TRPV1 receptor and how is it gated?

A

receptor is permeable to Na and Ca
heat gated, the warmer it is the easier it will open
also permeable to acids