Chapter 15:

Question 1

The nervous system has two main divisions

Answer 1

1. the central nervous system (CNS)
2. The PNS.

Question 2

PNS has two major subdivisions:

Answer 2

1. Somatic motor system
   Controls voluntary
   movement of muscles
2. Autonomic nervous system

Question 3

Somatic motor system

Answer 3

Controls voluntary
movement of muscles

Question 4

The autonomic nervous system is further subdivided into

Answer 4

1. The parasympathetic nervous system and
2. The sympathetic nervous system

Question 5

The two subdivisions of the ANS regulate?

Answer 5

The two subdivisions of the autonomic nervous system regulate many involuntary processes

Question 6

The autonomic nervous system has three principal functions:

Answer 6

1. Regulation of the heart;
2. Regulation of secretory glands
3. Regulation of smooth muscles

Question 7

Regulation of secretory glands

Answer 7

(salivary, gastric, sweat, and bronchial glands);

Question 8

Regulation of smooth muscles

Answer 8

(muscles of the bronchi, blood vessels, urogenital system, and gastrointestinal [GI] tract).

Question 9

The parasympathetic nervous system performs seven regulatory functions

Stimulation of appropriate parasympathetic nerves causes:

Answer 9

1. Slowing of heart rate
2. Increased gastric secretion
3. Emptying of the bladder
4. Emptying of the bowel
5. Focusing the eye for near vision
6. Constricting the pupil
7. Contracting bronchial smooth muscle

Question 10

Therapeutic agents that alter parasympathetic nervous system function are used primarily for

Answer 10

effects on the GI tract, bladder, and eye.

Occasionally, these drugs are also used for effects on the heart and lungs.

Question 11

The sympathetic nervous system has three main functions:

Answer 11

1. Regulating the cardiovascular system
2. Regulating body temperature
3. Implementing the acute stress response (commonly called a “fight-or-flight” reaction)

Question 12

Stimulation of sympathetic nerves to the heart

Answer 12

Stimulation of sympathetic nerves to the heart increases cardiac output.

Question 13

Stimulation of sympathetic nerves to arterioles and veins

Answer 13

Stimulation of sympathetic nerves to arterioles and veins causes vasoconstriction.

Question 14

Release of epinephrine from the adrenal medulla results in

Answer 14

Release of epinephrine from the adrenal medulla results in vasoconstriction in most vascular beds and vasodilation in certain others.

Question 15

By influencing the heart and blood vessels, the sympathetic nervous system can achieve three homeostatic objectives:

Answer 15

1. Maintenance of blood flow to the brain
2. Redistribution of blood flow during exercise
3. Compensation for loss of blood, primarily by causing vasoconstriction

Question 16

The sympathetic nervous system helps regulate body temperature in three ways:

Answer 16

1. By regulating blood flow to the skin, sympathetic nerves can increase or
   decrease heat loss.
2. Sympathetic nerves to sweat glands promote secretion of sweat, thereby helping the body cool.
3. By inducing piloerection (erection of hair), sympathetic nerves can promote heat conservation.

Question 17

When we are faced with an acute stress-inducing situation, the sympathetic nervous system orchestrates the fight-or-flight response, which involves:

Answer 17

1. Increasing heart rate and blood pressure
2. Shunting blood away from the skin and viscera and into skeletal muscles
3. Dilating the bronchi to improve oxygenation
4. Dilating the pupils (perhaps to enhance visual acuity)
5. Mobilizing stored energy, thereby providing glucose for the brain and fatty acids for muscles

Question 18

Agents that alter cardiovascular function are used to treat

Answer 18

1. hypertension,
2. heart failure,
3. angina pectoris,
4. and other disorders.

Question 19

What happens in many organs that receive dual innervation

Answer 19

The influence of sympathetic nerves opposes that of parasympathetic nerves.

Question 20

Example of influence of sympathetic nerves opposes that of parasympathetic nerves.

Answer 20

For example, in the heart, sympathetic nerves increase heart rate, whereas parasympathetic nerves slow heart rate

Question 21

The effects of sympathetic and parasympathetic nerves are complementary, rather than opposite. What is an example?

Answer 21

In the male reproductive system, erection is regulated by parasympathetic nerves and ejaculation is controlled by sympathetic nerves.

Question 22

A few structures under autonomic control receive innervation from only one division.

What is an example

Answer 22

Ex; blood vessels, which are innervated exclusively by sympathetic nerves.

Question 23

There are three basic patterns of autonomic innervation and regulation:

Answer 23

1. Innervation by both divisions of the autonomic nervous system in which the effects of the two divisions are opposed
2. Innervation by both divisions of the autonomic nervous system in which the effects of the two divisions are complementary
3. Innervation and regulation by only one division of the autonomic nervous system.

Question 24

Feedback regulation

Answer 24

is a process that allows a system to adjust itself by responding to incoming information.

Question 25

Synapse

Answer 25

junction (synapse) between these two neurons

Question 26

Ganglion

Answer 26

a mass of nerve cell bodies.

Question 27

Preganglionic neurons,

Answer 27

The neurons that go from the spinal cord to the parasympathetic ganglia

Question 27

postganglionic neurons.

Answer 27

the neurons that go from the ganglia to effector organs

Question 28

Neurons leading from ganglia to effector organs are termed

Answer 28

postganglionic neurons

Question 28

The anatomy of the parasympathetic nervous system offers two general sites at which drugs can act:

Answer 28

1. The synapses between preganglionic neurons and postganglionic neurons 2. The junctions between postganglionic neurons and their effector organs.

Question 28

Neurons leading from the spinal cord to the sympathetic ganglia are termed

Answer 28

preganglionic neurons

Question 29

What does the medulla of the adrenal gland release for the sympathetic nervous system:

Answer 29

releasing epinephrine into the bloodstream,

Question 30

As with the parasympathetic nervous system, drugs that affect the sympathetic nervous system have two general sites of action:

Answer 30

1. the synapses between preganglionic and postganglionic neurons (including the adrenal medulla), and 2. The junctions between postganglionic neurons and their effector organs.

Question 31

How many neurons are involved for somatic nervous system

Answer 31

there is only one neuron in the pathway from the spinal cord to the muscles innervated by somatic motor nerves.

Question 32

Having to do with administering drugs, how does having only 1 neuron involved in somatic motor nerves cause effects?

Answer 32

Because this pathway contains only one neuron, peripherally acting drugs that affect somatic motor system function have only one site of action: the neuromuscular junction (i.e., the junction between the somatic motor nerve and the muscle).

Question 33

The PNS employs three neurotransmitters:

Answer 33

1. Acetylcholine 2. Norepinephrine 3. Epinephrine 4. Dopamine- may also serve as a PNS transmitter, but this role has not been demonstrated conclusively

Question 34

What is the transmitter employed at most junctions of the PNS?

Answer 34

Acetylcholine

Question 35

Acetylcholine is the transmitter released by (5 things)

Answer 35

1. All preganglionic neurons of the parasympathetic nervous system, 2. All preganglionic neurons of the sympathetic nervous system 3. All postganglionic neurons of the parasympathetic nervous system, 4. All motor neurons to skeletal muscles, 5. Most postganglionic neurons of the sympathetic nervous system that go to sweat glands.

Question 36

Norepinephrine

Answer 36

Norepinephrine is the transmitter released by practically all postganglionic neurons of the sympathetic nervous system.

Question 37

What is the major transmitter released by the adrenal medulla?

Answer 37

Epinephrine (The adrenal medulla also releases some norepinephrine.)