Physio-Tactile and Position Senses (Brownell) Flashcards Preview

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Flashcards in Physio-Tactile and Position Senses (Brownell) Deck (10):

What is mechanoreception?

Ability of a cell to sense its own shape and tension.


What are the 2 types of mechanoreceptors? What info do they report? What are they based on?

1. Tonic receptors: slow adapting receptors that report amplitude and duration of stimulus.
2. Phasic receptors: fast adapting receptors that are sensitive to changes in stimulus strength.
• Based on how fast they get back to the baseline and adjust.


What are the 5 types of somatic sensory afferents?

1. Merkel’s disks
2. Meissner corpuscle
3. Pacinian corpuscle
4. Ruffini’s corpuscles
5. Hair follicle receptor


Merkel's Disks: receptive field size? Location? Function? Adaptive speed? Stimuli?

• Small receptive field.
• Location: tip of epidermal sweat ridges.
• Function: form and texture perception.
• Slow adaptive receptor.
• Responds to fine/small stimuli.
• Good at braille.


Meissner corpuscle: receptive field size? Location? Function?

• Small receptive field.
• Location: glabrous skin.
• Motion detection (skin motion); grip control; low frequency vibrations.


Pacinian corpuscle: receptive field size? Location? Function?

• Large receptive field.
• Location: dermis and deeper tissues.
• Sense vibrations (extremely sensitive).


Ruffini’s corpuscles: receptive field size? Adaptive speed?Function?

• Large receptive field.
• Slow adapting.
• Sense skin stretch; hand shape.


What is a hair follicle receptor sensitive to?

Displacement sensitive.


What leads to impulse propagation in somatosensory neurons?

Mechanotransduction (senses stretch in membrane) → activate voltage-gated channels → impulse generation/propagation.


Describe Somatotopic plasticity following amputation.

Removal of sensory input stimulates the outgrowth and remodeling of adjacent cortical receptive fields.

Activity dependent mapping. Use it or lose it.