Acetylcholine Synthesis, Release & Metabolism

Question 1

Select the true statements regarding acetylcholine. (Select 3.)

Answer 1

Let’s do this!!!

Question 2

—– is the primary transmitter in the parasympathetic nervous system

Answer 2

Acetylcholine

Question 3

Acetylcholine is the primary transmitter in the parasympathetic nervous system. It stimulates which 3 different receptor types in the body?

Answer 3

Nicotinic type N

Nicotinic type M

Muscarinic

Question 4

Nicotinic type N receptors are found in —–.

Answer 4

PNS ganglia

SNS ganglia

Central nervous system

Question 5

Nicotinic type M receptors are found at the —–.

Answer 5

Neuromuscular junction

Question 6

Muscarinic receptors found in the —– effector organs and in the —–.

Answer 6

Postganglionic PNS effector organs

Central nervous system

Question 7

Note that nicotinic receptors are —–, while muscarinic receptors are linked to —–.

Answer 7

ion channels

G- proteins

Question 8

—– starts the process of Ach synthesis

Answer 8

Choline

Question 9

Choline is transported from the —– into the —– of the nerve terminal

Answer 9

blood into the cytoplasm

Question 10

—– is produced in the mitochondria and released to the cytoplasm.

Answer 10

Acetyl Coenzyme A

Question 11

In the presence of the enzyme —–, choline and acetyl CoA are joined to form acetylcholine (Ach).

Answer 11

Choline acetyltransferase (ChAT)

Question 12

Acetylcholine is packaged into —–.

Answer 12

vesicles

Question 13

The —– initiates Ach release

Answer 13

Action potential

Question 14

The action potential depolarizes the —– terminal

Answer 14

nerve terminal

Question 15

Voltage-gated —– channels open

Answer 15

Ca+2 channels

Question 16

Voltage gated Ca+2 channels open and allow an influx of —– into the nerve terminal

Answer 16

Ca+2

Question 17

—– is required for Ach vesicles to fuse with the nerve terminal

Answer 17

Ca+2

Question 18

Ca+2 is required for Ach vesicles to fuse with the nerve terminal and release Ach via —– into the synaptic cleft.

Answer 18

exocytosis

Question 19

—– is an antagonist of Ca+2 at the presynaptic nerve terminal

Answer 19

Mg +2

Question 20

Mg +2 is an antagonist of Ca+2 at the presynaptic nerve terminal. This explains why Mg +2 can cause —– weakness

Answer 20

muscle weakness

Question 21

Mg +2 is an antagonist of Ca+2 at the presynaptic nerve terminal. This explains why Mg +2 can cause muscle weakness or how it acts synergistically with which drugs?

Answer 21

neuromuscular blockers

Question 22

Unlike norepinephrine, Ach is not —–

Answer 22

Ach is not reused

Question 23

Unlike norepinephrine, Ach is not reused and there is no —- mechanism

Answer 23

uptake mechanism

Question 24

Ach must be rapidly —– to allow precise control of the effector organs

Answer 24

metabolized

Question 25

Which enzyme quickly hydrolyzes Ach after it unbinds from these receptors

Answer 25

Acetylcholinesterase

Question 26

Acetylcholinesterase is also known as:

Answer 26

**true cholinesterase**

Question 27

Acetylcholinesterase (true cholinesterase) is positioned around the ----- receptors

Answer 27

**cholinergic** receptors

Question 28

The byproducts of Ach metabolism are ----- and -----

Answer 28

**choline** and **acetate**

Question 29

Choline is transported back into the -----.

Answer 29

**nerve terminal**

Question 30

Choline is transported back into the nerve terminal via -----.

Answer 30

**reuptake**

Question 31

Choline is transported back into the nerve terminal via reuptake and will serve as ----- for further Ach synthesis

Answer 31

**substrate**

Question 32

Acetate ----- away from the synaptic cleft

Answer 32

**diffuses**

Question 33

Select the true statements regarding acetylcholine. (Select 3.)

Answer 33

**Correct Answer:** Coenzyme A is produced in the mitochondria. Acetate is a metabolite of acetylcholine metabolism. Ach stimulates N-type cholinergic receptors in the sympathetic ganglia.

Question 34

----- hydrolyzes acetylcholine in the synaptic cleft.

Answer 34

**Acetylcholinesterase** | (not pseudocholinesterase)

Question 35

----- decreases acetylcholine release from the presynaptic nerve

Answer 35

**Hypermagnesemia** | (not hypomagnesemia)

Question 36

----- is the primary mechanism for acetylcholine's termination of action

Answer 36

**Metabolism** | (not reuptake)

Question 37

*Reference*

Answer 37

*Hemmings**.* *Pharmacology and Physiology for Anesthesia**.:* *Foundations and Clinical Application**.* *1st ed**.* *2013. p**.* *211.* *Flood* *.* *Stoelting's* *Pharmacology* & *Physiology* *in* *Anesthetic Practice. 5th* ed. *2015.* *p**.* ***84*** ***.***