The Nervous System

Question 1

purpose of the nervous system

Answer 1

directs and controls the voluntary movement

Question 2

the central nervous system (CNS) consists of

Answer 2

brain and spinal cord

Question 3

the peripheral nervous system (PNS) functions

Answer 3

to relay (peredavat’) nervous impulses from CNS to PNS (skeletal msucles etc.) and back.

Question 4

examples of somatic and autonomic NS

Answer 4

skeletal muscles and cardiac muscle, blood vessels

Question 5

neuron -

Answer 5

the most basic unit of the NS

Question 6

motor neuron/ efferent neuron -

Answer 6

the neurons that conduct impulses from the CNS to the skeletal msucles

Question 7

sensory/ afferent neuron

Answer 7

neurons that carrying impulses from PNS to the CNS (reading info such as stretch, pain, movement, tension)

Question 8

synapse

Answer 8

site of the communication b/n 2 neurons or neron and a gland/muscle cell etc.

Question 9

neuromuscular junction

Answer 9

synapse b/n motor neuron and skeletal muscle fiber

Question 10

dendrites

Answer 10

projections from the neuron cell body; serves to receive excitatory/ inhibitory signals from other neurons

Question 11

neuron dendrites and cell body are located in the

Answer 11

gray horn of the spinal cord

Question 12

axon extends outward the spinal cord and may innervate a muscle that is a great distance away from the spine.
The action potential causes release of …

Answer 12

Ach at the neuromuscular junction which leads to the muscle activation

Question 13

muscle spindle-

Answer 13

• spindle-shaped sensory organ; stretch receptor presented in the most muscles.
• responsible to sense changes in muscle length, particularly when the change is rapid.

Question 14

spindle structure -

Answer 14

enclosed in a capsule and lies || extrafusal fibers; contains specialized muscle fibers called intrafusal;
have actin and myosin in the ends and lots of sensory nerve endings in the middle.

Question 15

myotatic or stretch reflex

Answer 15

activation of the muscle as response to the stretch

Question 16

goldi tendon organ (GTO) located ..; function to…

Answer 16

located at the junction of the muscle and tendon;
function to protect muscle from injury;

Question 17

mechanism of GTO

Answer 17

sense the excessive force of muscle action, send the info to the CNS - relaxation of the working muscle and activation of the antagonist

Question 18

motor unit

Answer 18

motor neuron and muscle fibers it innervates

Question 19

motor neuron gives the fibers their … and … characteristics

Answer 19

metabolic and contractile

Question 20

2 mechanism of the force production

Answer 20

1) motor unit recruitment - vary number of the motor unitsrecruited
2) rate coding - increasing the rate of the motor units already activated;

Question 21

order of the motor unit recruitment

Answer 21

1) smaller type I are recruited first at the low-force muscle activation
2) type IIa; 3) IIx
2 and 3 require high intensity/load to be activated.

Question 22

people are able to recruit more motor units with…

Answer 22

training

Question 23

rate coding

Answer 23

if a muscle is stimulated to contract before it has a change to relax from a previous stimulus, it will produce greater force