Touch - Chapter 23

Question 1

How does a touch receptor code for stimulus intensity?

Answer 1

Increased firing rate

Question 2

Which mechanoreceptor type is located superficially in the dermis, is slowly adapting, has small receptive fields, and responds to light pressure?

Answer 2

Merkel

Question 3

Which mechanoreceptor type is located at deep layers in the dermis, is slowly adapting, has large receptive fields, and responds to pressure or stretch?

Answer 3

Ruffini

Question 4

Which mechanoreceptor type is located superficially in the dermis, is rapidly adapting, has small receptive fields, and responds to vibrations at 30-50 Hz?

Answer 4

Meissner

Question 5

Which mechanoreceptor type is located at deep layers in the dermis, is rapidly adapting, has large receptive fields, and responds to vibration at 100-300 Hz?

Answer 5

Pacinian

Question 6

What thalamic nucleus/nuclei is/are responsible for somatosensation?

Answer 6

VPL for body

VPM for neck and face

Question 7

What is the role of lateral inhibitory interactions in touch sensation?

Answer 7

Increases 2-point discrimination. Contributes to directional coding.

Question 8

Name and describe the somatosensory pathways at the level of the cortex.

Answer 8

Dorsal Stream: Somatosensory cortex projects to motor cortex to mediate somesthesis guided movements.

Ventral Stream: Somatosensory cortex projects to the parahippocampal cortex and limbic regions (hippocampus, amygdala) for object recognition and tactile memory development.