8.7

Question 1

a motorneuron innervates

Answer 1

Extrafusal muscle fiber / regular muscle fiber that id used to generate force

Question 2

gamma motorneuron innervates

Answer 2

Intrafusal muscle fibers = miscle spindle

Question 3

What ate intrafusal muscle fibers?

Answer 3

= muscle spindle
Very small
Run parallel to the extrafusal fibers
Common in muscle used for precise movements

Question 4

Muscle spindles are innervated by

Answer 4

Both afferent and efferent nerve fibers

Question 5

Two shapes of muscle spindle

Answer 5

Nuclear chain

Nuclear bag

Question 6

Which shape of muscle spindle is more common?

Answer 6

Nuclear chain

Nuclei are arrange in a row

Question 7

From where do nuclear chain fibers get their sensory innervation?

Answer 7

Group Ia (fast)
Group II (slower)

Question 8

From where do nuclear bag fibers get their sensory innervation?

Answer 8

Only from group Ia nerves

Question 9

Group Ia detect

Answer 9

Velocity of the fiber’s length change

Question 10

Group II detect

Answer 10

Length of the fiber

Question 11

Spinal cord reflexes

Answer 11

Stretch
Golgi tendon
Flexor withdrawal

Also-
Alternative rhythmic movement
Positive/negative supporting 
Baby
Gait/posture
Spinal righting

Question 12

Types of interneurons

Answer 12

1. Ia- inhibitor of antagonist muscle
2. Renshaw- modulate strength and firing rate of the a motorneuron
3. Ib- of Golgi tendon organ
4. Excitatory- used in the flexor-withdrawal reflex