Spinal reflexes Flashcards
1
Q
Muscle spindle
A
Stretch receptor
- senses change in muscle length
- arranged in parallel with extrafusal muscle fibers
2
Q
Gamma MNs
A
innervate intrafusal muscle fibers
- small diameter
- no force generation
- affect stiffness
- shortens the intrafusal muscle
3
Q
Intrafusal muscle fibers
A
Ia receptors and tyep II receptors
4
Q
Type Ia receptors
A
Dynamic- intense firing during stretch
bag fibers
5
Q
Type II receptors
A
Static- steady firing
increase with increasing stretch
chain fibers
6
Q
GTO type Ib
A
in series with extrafusal fibers
- active muscle contraction- causes firing of GTO
- Passive doesn’t fire GTO
7
Q
GTO reflex
A
fires Ib inhibitory interneurons
- inhibits homonymous muscle
- excites disynaptic pathway- excite antagonist muscle
8
Q
interneurons
A
amplify/distribute excitatory signal
change polarity of signal
