Nervous System

Question 1

Central nervous system (CNS)

Answer 1

– consists of the brain and spinal cord.

Question 2

Peripheral nervous system (PNS)

Answer 2

– consists of all the nerves originating at the brain and spinal cord and branching out to other parts of the body.

Question 3

Branches of the peripheral nervous system:

Answer 3

Somatic nervous system (SNS)

Autonomic nervous system (ANS)

Question 4

Somatic nervous system (SNS)

Answer 4

– nerves innervate the skin and skeletal muscle; usually associated with conscious activity.

In control

Question 5

Autonomic nervous system (ANS)

Answer 5

– nerves innervate the viscera; associated with unconscious activities.

No control

Question 6

Branches of the autonomic nervous system:

Answer 6

Sympathetic nervous system

Parasympathetic nervous system

Question 7

Sympathetic nervous system

Answer 7

• speed up heart rate

actions ready the body expend energy; secrete the neurotransmitter norepinephrine.

Inc. heart rate

• epinephrine/ norepinephrine
  o makes it easier to depolarize
  o results in increase heart rate

Question 8

Parasympathetic nervous system

Answer 8

• slow down heart rate

most active under resting conditions; may counterbalance sympathetic nervous system actions to restore resting conditions.

Dec. heart rate

• normal resting conditions
• rate of impulses indicates strength of impulse (faster impulse = stronger reaction; slower impulse = weaker reaction)
• Acetylcholine is released every time an impulse is released
  o makes it harder for heart to depolarize (contract)
  o heart rate is lower & slower ( resting conditions)