13 - Chemical Transmission

Question 1

List 2 types of ACh receptors

Answer 1

Nicotinic and Muscuranic

Question 2

1) Among subgroups of musacranic ACh receptors, they differ because
2) Nicotinic ACh receptors are grouped as… (3 total)

Answer 2

1) they can either be excitatory or inhibitory.
2)
- Neuromuscular
- Ganglionic
- CNS.
Note: ACh can fit into both type of receptors but nicotine and muscarine can’t fit into the other receptors.

Question 3

Effects of ACh? (7 total)

Answer 3

• Reduce heart function
• Increase secretions
• Increase GI motility
• Miosis of eye
• Vasodilation
• Bronchoconstriction
• Genitourinary

Question 4

Why don’t we use acetylcholine as a drug itself?
What do we use then?

Answer 4

• Lots of side effects (not local)
• Broken down easily by ACh esterase.

Pilocarpine. It’s a parasympathomimetic.
- Partial agonist to muscarinic receptors.
- Absorbed across conjunctiva easily
- Treat angle closure glaucoma, open angle glaucoma, ocular hypertension, pupil constriction, and dry mouth.

Question 5

1) Atropine is what type of drug?
2) What does it cause? (4 total)
3) What’s it good for?

Answer 5

1) Parasympatholytic
2)
- Mydriasis (7 – 10 days)
- Cycloplegia (7 – 10 days)
- Increase HR
- Reduce secretions
3) Good for organophosphate poisoning as that is caused by too many secretions building up in lungs.

Question 6

Describe atropine poisoning effects

Answer 6

• Hot as a hare
• Red as a beet
• Dry as a bone
• Blind as a bat
• Mad as a hatter
• Also, tachycardia, unconciousness

Question 7

How to Tx atropine poisoning?

Answer 7

An acetylcholine esterase inhibitor (e.g. physotigmine). This will increase acetylcholine levels to up PNS to counter tha SNS increase.

Question 8

What’s hyoscine?

Answer 8

Natural product used to counter motion sickness.

Question 9

1) What is ipratropium bromide? Used in…
2) Why might there be ocular SEs?

Answer 9

1) Non-specific antagonist that causes bronchodilation.
- Used in Chronic Obstructive Pulmonary Disease (COPD) and Asthma
2) Inhaler not used correctly so drug gets into eye. Can cause blurred vision, acute angle glaucoma.

Question 10

Describe 4 types of drugs that affect nicotinic ACh receptors

Answer 10

• Ganglion-stimulating
• Ganglion-blocking
• Neuromuscular junction agonist
• Neuromuscular junction antagonist

Question 11

Describe Nicotine effects

Answer 11

• Acts on Nic ACh receptors
• A ganglion-stimulating drugs
• Initially, it stimulates both SNS and PNS. Newcomers will experience the SNS more so causes stuff like nausea and vomiting along with SNS stuff. Eventually, PNS becomes more noticeable with repeat smoking so becomes more relaxing.

Question 12

Describe ganglion blocker example.

Answer 12

Triometaphan is occasionally used to lower BP during emergency surgery. Otherwise, not used due to varriation and uncontrollability.

Question 13

Describe neuromuscular junction agonists

Answer 13

Actually used to relax muscles. An example is suxamethonium which causes constant stimulation of the muscles until it tires out which essentially paralyses it.
- Quick and short acting. Good for short emergency procedures.
- Irreversible effects.
- Depolarising neuromuscular blockade.

Question 14

Describe neuromuscular junction antagonists

Answer 14

Non-depolarising skeletal muscle relaxants. Competitive antagonist to motor endplate and blocks ACh.
- Good for longer lasting procedures
- Is reversed by anticholinesterase.

Question 15

Describe how non-receptor drug targets could work.
- List 3

Answer 15

Inhibits:
- Esterases like cholineesterases.
- Synthesis
- Release

Question 16

List 3 adrenergic transmitters.

Answer 16

NA, Dopamine, Adrenaline.

Question 17

Alpha 1 blockers typically used for…

Answer 17

• BP medication to lower BP
• Increase urinary flow in benign prostatic hypertrophy

Question 18

Beta blockers typically used for…

Answer 18

Cardiovascular issues but also other large range of problems.