Acetylcholine

Question 1

ACh plays a crucial role in both

Answer 1

sympathetic
and parasympathetic branches of the autonomic
nervous system.

Question 2

ACh is responsible for muscle contractions, as it is released at

Answer 2

neuromuscular junctions.

Question 3

Many drugs, cosmetics and toxins act on the …. system

Answer 3

cholinergic

Question 4

what is Botulin Toxin produced by

Answer 4

the bacteria Clostridium botulinum.

Question 5

Botox interferes with Ach release at nerve terminals, thereby blocking

Answer 5

neurotransmission

Question 6

what was the first neurotransmitter discovered

Answer 6

acetylcholine

Question 7

Sympathetic and
parasympathetic preganglionic
neurons

Answer 7

are cells in the CNS
that send axons to the
autonomic ganglia and various
target organs.

Question 8

ACh is the neurotransmitter used
for

Answer 8

communication

-Mediates parasympathetic
functions (e.g. inhibits heart);
- Released onto muscles leading to
muscle contraction (activates)

Question 9

characteristics of sympathetic division

Answer 9

• energy mobilization
• origin in thoracic and lumbar spina cord
• relatively short preganglionic fibres, long post ganglionics
• releases acetylcholine in ganglia and norepinephrine at target

Question 10

characteristics of parasympathetic division

Answer 10

• energy conservation and storage
• origin in cranial nerves and sacral spinal cord
• long preganglionic fibres ending near organs, short postganglionic
• releases ACH t both ganglia and target

Question 11

ACh is formed from

Answer 11

choline and acetyl coenzyme A
(Acetyl CoA)

Question 12

The reaction of Ach is catalyzed by

Answer 12

choline acetyltransferase

Question 13

Choline

Answer 13

an essential nutrient found in
many foods, principally in the form of
phosphatidylcholine and as free choline.
- Phosphatidylcholine: beef liver, egg yolks, soya;
- Free choline: beef liver, iceberg lettuce, peanut
butter, peanuts, cauliflowe

Question 14

Acetyl CoA is produced during the 2nd step of

Answer 14

aerobic cellular respiration

Question 15

ChAT is synthesized within the.. and transported to .. it is also used as a marker for…

Answer 15

ChAT is synthesized within the cell body and
transported to the nerve terminal.

marker for motor neurons

Question 16

ACh is stored in

Answer 16

very small
synaptic vesicles

Question 17

Vesicular ACh Transporter
(VAChT) is responsible for

Answer 17

loading ACh into vesicles

Question 18

Cholinergic cell bodies are primarily located in
the:

Answer 18

1. Caudate putamen;
2. Nucleus Accumbens;
3. Nucleus basalis;
4. Pedunculopontine Nuclei (PPN);
   i. Laterodorsal tegmental nucleus
   ii. Pedunculopontine tegmental nucleus
5. Medial Septum

Question 19

two families of cholinergic receptors
distributed throughout the brain

Answer 19

1. Nicotinic acetylcholine receptors
2. Muscarinic acetylcholine receptors

Question 20

Nicotinic acetylcholine receptor

Answer 20

Respond to nicotine
- Localized at neuromuscular junctions;
- Ionotropic receptors;

Question 21

Each nicotinic receptor consists of how many subunits

Answer 21

5

Question 22

When nicotinic receptors are
subjected to continuous agonist
exposure, they become

Answer 22

desensitized – the channel will not
open even when agonist binds;
- Desensitized receptors will
naturally, and spontaneously, re-
sensitize and are able to respond
again

Question 23

Muscarinic acetylcholine receptors

Answer 23

Responds to muscarin
- Unlike nicotinic receptors, muscarinic receptors are
metabotropic  operate via 2nd messenger system

Question 24

how many subunits muscarinic receptor are they and where are they found

Answer 24

5
- M1 are common in secretory glands;
- M2 are found in cardiac tissue;
- M3 are found in smooth muscles and in secretory glands

Question 25

M1,M3 & M5 receptors cause the activation of

Answer 25

phospholipase C, leading to an intracellular increase of
Ca2+

Question 26

M2 & M4 inhibit

Answer 26

adenylyl cyclase, which decreases the
production of cAMP

Question 27

M5 receptors in the brain are primarily in the

Answer 27

hippocampus,
hypothalamus, and midbrain dopamine areas

They contribute to the excitatory effect on dopamine neurons
mediated by nicotinic receptors;
- They appear to be involved in the rewarding and dependence-
producing effects of some illicit drugs.

Question 28

Cellular acetylcholine levels are
regulated by an enzyme called

Answer 28

acetylcholinesterase (AChE)

Question 29

AChE breaks down ACh into

Answer 29

choline
and acetic acid

Question 30

AChE is located in multiple places:

Answer 30

• Presynaptic cells so they can metabolize
  excess ACh;
• Postsynaptic membrane so they can
  break down ACh after its release into
  synaptic cleft

Question 31

Some compounds cause irreversible
inhibition of AChE, what does this result in

Answer 31

• This would prevent acetylcholine from being
  metabolized;
• Acetylcholine would therefore remain in the cleft to
  continue binding and activating receptors.

Question 32

ACh accumulation and overstimulation of
cholinergic synapses throughout both CNS and PNS lead to

Answer 32

muscle paralysis and death by
asphyxiation

Question 33

Alzheimer’s Disease (AD) is associated with a loss of.. that project from the … to the ….

Answer 33

loss of cholinergic neurons that
project from the basal forebrain to the cerebral cortex and hippocampus

Question 34

Pyruvate decarboxylation

Answer 34

conversion of
pyruvate, the end product of glycolysis, into
acetyl CoA