chapter 16.3

Question 1

When stimulated, sympathetic preganglionic neurons release

Answer 1

acetylcholine (ACh) at synapses with ganglionic neurons. The effect on the ganglionic neurons is always excitatory.

Question 2

What happens when the ganglionic neurons are stimulated?

Answer 2

These ganglionic neurons then release neurotransmitters at specific target organs.

Question 3

What is varicosities?

Answer 3

he telodendria form a branching network, with each branch resembling a string of pearls. Each “pearl” is a swollen segment called a varicosity that is packed with neurotransmitter vesicles

Question 4

What neurotransmitter is released from most varicosities in the sympathetic division?

Answer 4

Norepinephrine (NE) is released from most varicosities in the sympathetic division.

Question 5

Neurons that release NE are called

Answer 5

adrenergic

Question 6

Synapses that use ACh as a transmitter are called

Answer 6

cholinergic

Question 7

Varicosities releasing ACh are located in

Answer 7

he body wall, the skin, the brain, and skeletal muscles.

Question 8

What are two classes of these adrenergic receptors.

Answer 8

alpha receptors and beta receptors.

Question 9

What Receptor does NE affect to a higher degree?

Answer 9

stimulates alpha receptors to a greater degree than it does beta receptors

Question 10

What does E stimulate?

Answer 10

both classes of receptors

Question 11

What are alpha and beta receptors

Answer 11

G-protein–coupled receptors.

Question 12

What are the two types of alpha protein?

Answer 12

alpha-1 (α1) and alpha-2 (α2).

Question 13

Describe alpha-1.

Answer 13

the more common type of alpha receptor, is found primarily in smooth muscle cells of many different organs. stimulation of α1 receptors on smooth muscle cells causes peripheral blood vessels to constrict and sphincters along the digestive tract and urinary bladder to close.

Question 14

Describe alpha 2

Answer 14

receptors are found on preganglionic or postganglionic sympathetic neurons. The presence of α2 receptors in the parasympathetic division helps coordinate sympathetic and parasympathetic activities.

Question 15

Where are beta receptors located

Answer 15

are located on the plasma membranes of cells in many organs, including skeletal muscles, the lungs, the heart, and the liver.

Question 16

There are three major types of beta receptors

Answer 16

beta-1 (β1), beta-2 (β2), and beta-3 (β3).

Question 17

Describe beta 1

Answer 17

leads to an increase in metabolic activity
The stimulation of β1 receptors in the heart increases heart rate and force of contraction.

Question 18

Describe beta 2

Answer 18

causes inhibition, triggering the relaxation of smooth muscles along the respiratory tract.As a result, respiratory passageways dilate, making breathing easier.

Question 19

Describe beta 3

Answer 19

Stimulation of β3 receptors leads to lipolysis, the breakdown of triglycerides stored within adipocytes.
Energy reserve, provides more ATP

Question 20

A person with high blood pressure is given a medication that blocks beta receptors. How could this medication help correct that person’s condition?

Answer 20

Blocking the beta receptors on cells would decrease or prevent sympathetic stimulation of tissues containing those cells. Heart rate, force of contraction of cardiac muscle, and contraction of smooth muscle in the walls of blood vessels would decrease, lowering blood pressure.

Question 21

How would a drug that stimulates cholinergic receptors affect the sympathetic nervous system?

Answer 21

Because preganglionic fibers of the sympathetic nervous system release acetylcholine (ACh), a drug that stimulates cholinergic receptors would stimulate the postganglionic fibers of sympathetic nerves, resulting in increased sympathetic activity.