Chapter 13 Physiology of the PNS

Question 1

Cholinergic Receptors

Answer 1

Receptors that mediate responses to acetylcholine

Question 2

Adrenergic receptors

Answer 2

Receptors that mediate responses to epinephrine and norepinephrine

Question 3

Receptor Subtypes

Answer 3

Receptors that respond to the same transmitter but are different from each other. Allow for greater drug selectivity. For instance Nicotinic Cholinergic Receptors and Muscarinic Cholinergic Receptors both respond to acetylcholine, but only nicotinic receptors respond to nicotine, and only muscarinic receptors respond to muscarine

Question 4

Nicotinic(N)

Answer 4

Cholinergic receptors found on the post ganglionic neuron of both the PSNS and SNS. Promotes ganglionic transmission of all ganglia. Additionally, promotes release of epinephrine from the adrenal medulla

Question 5

Nicotinic(M)

Answer 5

Cholinergic receptor found on skeletal muscle.

Question 6

Muscarinic

Answer 6

Cholinergic receptors found on targeted organs of the PNS. 7 main functions are

1. Increased glandular secretions (pulmonary, gastric, intestinal, and sweat)
2. Contraction of smooth muscle in the bronchi and GI tract
3. Slowing of the heart
4. Miosis (decreased pupil size)
5. Contraction of the ciliary muscle, causing focusing of the lens
6. Dilation of blood vessels
7. Voiding of the bladder

Question 7

Acetylcholine

Answer 7

Neurotransmitter released by all of the preganglionic neurons of the PSNS and SNS, all postganglionic neurons of the PSNS, all motor neurons to skeletal muscles, and most postganglionic neurons of the SNS that go to sweat glands. Able to activate all three cholinergic receptor subtypes

Question 8

Alpha 1

Answer 8

An Adrenergic Receptor Subtype located in the eyes, blood vessels, male sex organs, prostatic capsule, and bladder (trigone and sphincter). When activated, results in

1. Mydriasis (increased pupil size)
2. Constriction of veins and arterioles
3. Penile ejaculation
4. Contraction of the bladder

Question 9

Alpha 2

Answer 9

An Adrenergic Receptor Subtype located on nerve terminals. Referred to as prejunctional or presynaptic. Regulate transmitter release

Question 10

Beta 1

Answer 10

An Adrenergic Receptor Subtype located in the heart and kidneys. In the heart, activation of Beta 1 receptors promotes increased heart rate, contraction, and velocity of impulse conduction through the AV node. In the kidneys, activation of Beta 1 receptors causes release of Renin into the blood

Question 11

Beta 2

Answer 11

An Adrenergic Receptor Subtype located in arterioles of the heart, lungs, and skeletal muscle (vasodilation), bronchi (dilation), uterus (relaxation), liver (glycogenolysis), and skeletal muscle (enhanced contraction, glycogenolysis. Can only be activated by epinephrine and are activated during fight or flight response.

Question 12

Dopamine (R)

Answer 12

An Adrenergic Receptor Subtype. The most clinical significance is dopamine receptors found in the vasculature of the kidney, where activation results in dilation of renal blood vessels resulting in increased perfusion

Question 13

Epinephrine

Answer 13

A neurotransmitter capable of activating all of the adrenergic receptors apart from dopamine receptors. Released by the adrenal medulla, it prepares the body for fight or flight.

Question 14

Norepinephrine

Answer 14

A neurotransmitter capable of activating Alpha 1, Alpha 2, and Beta 1.

Question 15

Dopamine

Answer 15

A neurotransmitter capable of activating Alpha 1, Beta 1, and Dopamine