CH 2: Nervous System

Question 1

3 types of neurons

Answer 1

1) motor. FROM the brain/spinal cord TO the muscles and glands
2) sensory. TO brain/spinal cord
3) interneurons. most abundant in the nervous system; creates circuits b/w motor and sensory neurons; can inhibit other neurons

Question 2

A neuron includes what components?

Answer 2

dendrites (receivers)
cell body (nucleus)
axon (transmitter)

Question 3

muscle spindle

Answer 3

detects changes in muscle length
runs alongside the muscle

Question 4

golgi tendon

Answer 4

detects changes in tension
sits b/w muscle and tendon

Question 5

number of nerves in PNS?

Answer 5

43

Question 6

number of spinal nerves?

Answer 6

31

Question 7

what are the spinal nerves and how many pair of each?

Answer 7

cervical (8)
thoracic (12)
lumbar (5)
Sacral (5)
coccygeal (1)

Question 8

why is 33% of 1RM the ideal percentage to use for power exercises?

Answer 8

due to motor unit recruitment and encoding rate, or how many muscles fibers get recruited and how fast they do so

Question 9

what is another name for Henneman’s principle? what is the principle?

Answer 9

Size Principle
Henneman’s principle states muscle fibers are recruited in order from slowest to fastest. In other words, more fibers are recruited the more force is needed

Question 10

describe the 3 types of fibers

Answer 10

slow, type I
fast fatigue resistant (FFR), type IIa
fast fatigable (FF), type IIx

Question 11

Describe the differences in the fiber types

Answer 11

Type I - slow twitch, contract for hours or days, small bundle of fibers

Type IIa - fast twitch, contract for minutes, moderate size bundle

Type IIx - fast twitch, contract for 5-10sec, large bundle

Question 12

Sensory receptors

Answer 12

include muscle spindles and golgi tendons organs, both of which influence interneurons so the interneurons know to inhibit action or not.

Question 13

describe the process of sensory reception

Answer 13

sensory feedback from the receptors (muscle spindles and golgi tendon organs) is sent to the brain and spinal cord, while interneurons integrate signals to inhibit the appropriate motor neuron pools. Then the basal ganglia sends refinement commands to “smooth out” movement

Question 14

Describe the basal ganglia

Answer 14

regulates the smoothness and speed of mvmt.

sends refinement commands after receiving input from the sensory receptors to fine-tune, coordinate, and regulate movement.

A dysfunctional basal ganglia leads to movement disorders such as Parkinson’s or Huntington’s disease.