Exam II: The Autonomic Nervous System

Question 1

What are the three components of the nervous system?

Answer 1

Brain
Nerves (pathways of communication)
Neurotransmitters

Question 2

What are the two major sections of the Autonomic Nervous System?

Answer 2

Sympathetic (thoracolumbar)

Parasympathetic (craniosacral)

Question 3

What are the 2 key neurotransmitters of the Autonomic NS?

Answer 3

1. Acetylcholine

2. Norepinephrine

Question 4

Where is acetylcholine released from?

Answer 4

Cholinergic nerve fibers

Question 5

All efferent fibers leaving the CNS are ____.

Answer 5

Cholinergic

Question 6

Describe how ACh is made

Answer 6

ACh is made from acetyl-CoA using an enzyme called choline 0-acetyltransferase.

It is synthesized in the mitochondria

After made, it is transfered to neuronal terminal by a choline transporter and stored as “quanta” in vesicles in nerve terminals

Question 7

What does Acetylcholinesterase (AChE) do?

Answer 7

Breaks down ACh into choline and acetate

Question 8

_____ release norepinephrine

Answer 8

Adrenergic nerve fibers

Question 9

Where are adrenergic nerve fibers found?

Answer 9

Make up the postganglionic neurons of sympathetic nervous system

Question 10

What are the actions of norepinephrine? (HINT: 5 actions)

Answer 10

1. Increase HR and BP
2. Mobilize energy stores
3. Increase blood flow to skeletal muscle
4. Divert blood flow from skin and internal organs
5. Dilate pupils and bronchioles

Question 11

What are the 3 termination methods of adrenergic action?

Answer 11

1. NE metabolized by catalytic enzymes
2. Diffusion away from receptor site
3. Reuptake into terminal by norepinephrine transporter (NET) or other cells

Question 12

What are the two types of Cholinergic receptors?

Answer 12

1. Muscarinic

2. Nicotinic

Question 13

What are the three types of Adrenergic receptors?

Answer 13

1. Alpha 1 and Alpha 2
2. Beta 1 and Beta 2
3. Dopamine

Question 14

What are two drugs that inhibit NET?

Answer 14

Cocaine

Tricyclic Antidepressants

Question 15

Which organ system is the major target of the Autonomic Nervous System?

Answer 15

Cardiovascular System

Question 16

Why is there a control function of the autonomic system? (2 reasons)

Answer 16

1. To prevent system from overstimulation

2. Maintain effector organ functions within a narrow window of tolerance

Question 17

What 3 mechanisms control autonomic nervous system?

Answer 17

1. Presynaptic regulation
2. Postsynaptic regulation
3. Other integrated systems

Question 18

2 examples of presynaptic regulation

Answer 18

alpha2 receptors: when activated by NE, they decrease the amount of NE released from that same nerve cell (autoreceptor)

Beta receptors facilitate the release of more NE

Question 19

Two mechanisms of postsynaptic regulation

Answer 19

1. Up or down regulate receptors

2. Action of one receptor is affected by action of other receptors

Question 20

What controls the iris radial muscle?

Answer 20

alpha 1 receptors

Question 21

What controls the iris circular muscle and the ciliary muscle?

Answer 21

M3 receptors (muscarinic)