Neurocircuits-fibers Flashcards
1
Q
1a fibers
A
- innervate nuclear bag and chain fibers of muscle spindles via annulospiral endings
- info: muscle length and rate of change of muscle length
2
Q
II fibers
A
- innervate static bag and chain fibers of muscle spindles via flower spray endings. Both muscle sensory and fine tactile (epicritic) fibers.
- info: muscle length
3
Q
1b fibers
A
- innervate Golgi tendon organs
- info: muscle tension
4
Q
A-beta fibers
A
- innervate tactile receptors (Meissner, Merkel, Pacinian, Ruffini, hair)
- info: fine touch and vibratory
5
Q
A-delta fibers
A
- slow, small, and lightly myelinated. terminate as free nerve endings
- info: sharp pain and cold sensation. Visceral and joint receptors, preganglionic fibers (B type)
6
Q
C fibers
A
- slow, small, unmyelinated. terminate as free nerve endings
- info: dull pain and warmth. Some visceral receptors, post ganglion is fibers, itch receptors.
7
Q
A-gamma fibers
A
- from gamma motor neurons
- adjust sensitivity of muscle spindles
8
Q
A-alpha fibers
A
- from alpha motor neurons
- control muscle contraction
9
Q
Medial division fibers
Which, info, and projections
A
1a, 1b, II, A-beta
Info: epicritic info of proprioception, fine touch, and vibratory sense. Also participate in reflex circuits
Projections: dorsal column (FG, FC) and laminar III-IX of SC
10
Q
Lateral Division Fibers
Which, info, and projections
A
- A-delta and C
- info: protopathic info of pain and temp
- projections: laminae I, II, and V. Can be part of Lissauer’s tract
11
Q
Merkel cell
A
Pressure, texture
12
Q
Ruffini corpuscle
A
Skin stretch
13
Q
Meissner corpuscle
A
Stroking, fluttering
14
Q
Pacinian corpuscle
A
Vibration
15
Q
Hair receptors
A
Light stroking
