Misc. Facts Flashcards
Aα fibers
aka 1a 1b
Largest, myelinated neurons. found in the center of the muscle spindle (1a) and the golgi tendons (1b)
Aβ fibers
aka 2
second largest myelinated neurons. found in the edges of the muscle spindle and skin mechanoreceptors (pacinian, merkel, etc.)
Aδ fibers
aka 3
seconds smallest myelinated neurons. transmit pain and temperature information
C fibers
aka 4
smallest unmyelinated neuron. transmit pain and temperature information
What reflexes are the flexor reflex afferents involved in?
corneal blink reflex, Babinski reflex, and the flexor (withdrawal reflex).
These are all protective reflexes.
What type of fibers transmit the afferent portion of the protective reflexes?
Aδ fibers or C (3 or 4) fibers because they are transmitting noxious afferent stimuli information.
Hair Follicle Ending
senses: hair follicle displacement
location: hair follicle
fiber: Aβ/2
Pacinian Corpuscle
senses: fast vibration
location: deep dermis in hairy/glabrous skin
fiber: Aβ/2
Ruffini Ending
senses: pressure
location: dermis of hairy/glabrous skin
fiber: Aβ/2
Krause Endbulb
senses: pressure
location: lips, tongue, genitals
fiber: Aβ/2
Meissner Corpuscle
senses: vibration
location: dermis of glabrous skin
fiber: Aβ/2
Merkel Cells
senses: pressure
location: epidermis of glabrous skin
fiber: Aβ/2
Free Nerve Ending
senses: pain and temperature
location: ubiquitous
fiber: Aδ and C/ 3 and 4
What do α motor neurons innervate?
extrafusal muscle fibers
What do γ motor neurons innervate?
intrafusal muscle fibers
