SENSORY MECHANISMS

Question 1

What are the 4 types of fibers? What mechanism are they a part of?

Answer 1

Group A-a = fastest/largest
1a - muscle spindle - detect stretch, 1b - GTO
Group A-b aka Group 2
2 - touch, propreioception (Ruffini), pressure (Merkel), vibrations (Pacinian)
Group A-g aka Group 3
3 - pain, temperature

Question 2

What is a glabrous surface?

Answer 2

Smooth, hairless surface

Question 3

What sensory receptors are a part of the epidermis?

Answer 3

Superficial mechanoreceptors; Meissner (most superficial), Merkel

Question 4

What sensory receptors are below the epidermis but above hypodermis?

Answer 4

With the DERMIS; deep mechanoreceptors:

Deepest Pacinian, Ruffini

Question 5

What is the RF, Concentration, Fxn of the 4 common mechanoreceptors? Order RF, [], Fxn

Answer 5

Meissner = low, highest, change in velocity (rate)
Merkel = lowest, high, indentation
Ruffini = high, low, proprioception
Pacinian = highest, lowest, vibration

Question 6

For type C fibers, what is there pattern of response?

Answer 6

Increase Hz of AP with the duration of the stimulus

Question 7

The somatosensory information from the body (not the face) projects to what part of the thalamus?

Answer 7

The medial lemniscus projects to the Ventral Posterior Thalamus - the LATERAL ASPECT.

Question 8

What is the Muscle Spindle? (Afferent, Muscle Fiber arrangement, Synapses, Fxn)

Answer 8

1. 1a/1b
2. Parallel to the muscle fibers
3. Monosynaptic –> 3 synapses (IN, a/g MN)
4. Detect the amount of stretch