Nerve Fibers

Question 1

What is the axon classification based on size called?

Answer 1

Erlanger - Gasser

Question 2

What is the name of the classification system for sensory root nerves?

Answer 2

Llyod - Hunt

Question 3

What is thel diameter and speed of conduction of an A-alpha fiber?

Answer 3

Diameter: 13 - 20 um
Speed: 80 - 120 m/sec

Question 4

What is the diameter and speed of conduction of an A-beta fiber?

Answer 4

Diameter: 6 - 12 um
Speed: 35 - 75 m/sec

Question 5

What is the diameter and speed of conduction of an A-delta fiber?

Answer 5

Diameter: 1 - 5 um
Speed: 5 - 30 m/sec

Question 6

What is the diameter and speed of conduction of a C fiber?

Answer 6

Diameter: 0.2 - 0.05 um
Speed: 0.5 - 2 m/sec

Question 7

What do A-alpha fibers innervate?

Answer 7

• Extrafusal muscle

Question 8

What do A-beta fibers innervate?

Answer 8

• Extrafusal and intrafusal muscle fibers

Question 9

What do A-gamma fibers innervate?

Answer 9

• Intrafusal muscle fibers

Question 10

What do B and C fibers innervate?

Answer 10

• Preganglionic and post ganglionic fibers

Question 11

What do Ia fibers innervate?

Answer 11

• Primary afferent of muscle spindles

Question 12

What do Ib fibers innervate?

Answer 12

• Golgi tendon organs

Question 13

What do II fibers innervate?

Answer 13

• Secondary afferents of muscles spindles
• Touch and pressure receptors
• Pacinian corpuscles (vibration)

Question 14

What do III fibers innervate?

Answer 14

Small, lightly myelinated fibers for:

• Touch and pressure
• Pain
• Temperature

Question 15

What do IV fibers innervate?

Answer 15

• Pain and temperature receptors