L1 ANS

Question 1

Autonomic Nervous System

Answer 1

– innervates all tissues except skeletal muscle
– operates outside conscious control
– essential role in homeostasis

Question 2

Sensory Nervous System

Answer 2

– detects stimuli inside and outside the body
– transmits to specific brain regions for processing
– external stimuli – light, sound, smell, touch, taste
– internal stimuli – O2 concentration, pressure, pH

Question 3

Somatic Nervous System

Answer 3

– skeletal muscle nervous system
– voluntary movement of skeletal muscle

Question 4

Name the two neurones synapse in specialised autonomic ganglia

Answer 4

• Preganglionic neurone
  – neurone with cell body in CNS
• Postganglionic neurone
  – neurone with cell body in ganglia

Question 5

• Preganglionic neurone
• Postganglionic neurone

Answer 5

– neurone with cell body in CNS
– CNS origin is the basis of initial classification of sympathetic and parasympathetic divisions

– neurone with cell body in ganglia
– innervates the target tissue

Question 6

Sympathetic neurotransmitter release simple

Answer 6

CNS→ganglion→ACh→Nicotinic receptors→postganglionic neuron→Noradrenaline in neuroeffector juction→alpha/beta adrenoceptors

Question 7

Parasympathetic Neurotransmitter release

Answer 7

CNS→preganglionic neuron→ACh→ganglion/nicotinic receptors→ACh→muscarinic receptors

Question 8

PNS

Heart

Answer 8

↓ rate (bradycardia)

Question 9

PNS

Lungs

Answer 9

bronchoconstriction, secretion

Question 10

PNS

GI tract

Answer 10

↑ tone, motility of small & large intestine, ↑ secretion of saliva and gastric acid

Question 11

PNS

Glands

Answer 11

↑sweating, salivation, lacrimation

Question 12

PNS

Eye

Answer 12

sphincter muscle contraction, ciliary muscle contraction

Question 13

PNS

Blood vessels

Answer 13

most blood vessels not innervated vasodilatation in some vessels

Question 14

How acetylcholine is formed

Answer 14

Choline + acetyl-Co-enzyme A
|
Choline acetyltransferase
↓
Acetylcholine

Question 15

Cholinergic Synapse routes of ACh

Answer 15

1. Diffuse
2. (Might cross synapse but don’t hv to) ACh-esterase →choline (+ acetyl-co-A→ACh
3. M2 receptors that will decrease production of ACh
4. M3 receptors that will cross the synapse and cause contractions in smooth muscle

In chlinergic veins`

Question 16

Parasympathomimetic Agents:

Answer 16

• Acetylcholine
• Muscarine
• Nicotine

Question 17

Parasympathomimetic Agent Acetylcholine

Answer 17

• Nico and Muscar
• Stim those receptors
• Agonist at ganglionic (nico) and postganglionic (mascarinic) receptors

Question 18

Parasympathomimetic agent: Muscarine

Answer 18

• Alkaloid obtained from Amanita muscaria (toadstool)
• Quaternary ammonium compound
• Resistant to acetylcholinesterase
• Selective for muscarinic receptors (postganglionic)
• Does not stimulate nicotinic (ganglionic) receptors

Question 19

Parasympathomimetic agent: Nicotine

Answer 19

• No resemblance to either ACh or muscarine
• Selective for nicotinic (ganglionic) receptors
• Does not stimulate muscarinic (postganglionic) receptors

Question 20

Parasympathetic agent agonist will

Answer 20

Stimulates the receptor
Mimics acetylcholine

Question 21

Parasympathetic agent antagonist will

Answer 21

Binds to the receptor
Blocks effects of acetylcholine

Question 22

Parasympathetic agent chonlinesterase inhibitor will

Answer 22

• Inhibits metabolism of acetylcholine
• Acetylcholine levels increase
• Effects of receptor stimulation are potentiated / prolonged

Question 23

Analogues of ACh

Answer 23

• ACH (M&N) - highly susceptable to ACH Est (+++) [short acting]
• Methacholine (M) - more resistant to ACH Est (+) [longer acting]
• Carbachol (M&N) - resistant to ACH Est (-) [long acting]
• Pilocarpine (M) - resistant to ACH Est (-) [miotic agent ↑ glandular secretion]

Car- NH2
Meth-CH3

Question 24

Anterior Chamber of the Eye

Answer 24

• response to increased light
• accommodation for near vision
• aqueous humour

Question 25

Uses of Muscarinic Agonists and open angle glaucoma

Answer 25

* Treats *open angle glaucoma* where pressure inside eye increases and can cause optic nerve damage * When pupil is dilated it hinders drainages of aqueous humour * the iris will fold at an angle and block where the aqueous humour is supposed to drain * Muscarinic agonist will stim the parasympathetic NS leading to pupil constriction (miosis), opening the drainage angle and aqueous humour flow out of eye more ↓ * Reducing the intraocular pressure.

Question 26

Uses of Muscarinic Agonists and urinary rentention

Answer 26

* Condition where person cannot empty bladder * Muscarinic will contraction of bladder muscles helping urination

Question 27

Uses of Muscarinic Agonists and paralytic Ilieus

Answer 27

* Condition where intestines can't move food and waste through DT * Mscarununc receptors in GI tract promote constriction of smooth muscles in intestines to restore bowel movements.

Question 28

Shouldn't use muscarinic agnoist if you have what diseases/conditions

Answer 28

* Asthma - bronchoconstriction, hypersecretion of mucus * Peptic ulcer - ↑gastric acid secretion * Heart attacks - bradycardia causing coronary insufficiency * Hyperthyroidism - hypersecretion of thyroid hormone↑↑

Question 29

ACh-Est and Cholinergic Synapse diagram

Answer 29

* ACh to M/N * ACh to ACh-est → Choline + acetic acid = taken back up to synthesise more ACh

Question 30

ACh-Est stucture

Answer 30

* Anionic site for ACh's N+ * esteratic site for ACh's ester

Question 31

Cholinesterase Inhibitors

Answer 31

* Cholinesterase catalyse hydrolysis of Ach – acetylcholinesterase + pseudocholinesterase * Acetylcholinesterase terminates action of ACh at nerve terminals * Cholinesterase **inhibitors** inhibit catalytic activity of cholinesterase enzymes – ACh accumulates ↑ – neurotransmission increases

Question 32

Name a short-acting Cholinesterase Inhibitor

Answer 32

Edrophonium

Question 33

Edrophonium

Answer 33

– combines reversibly with acetylcholinesterase – effective for only a few minutes – used to diagnose myasthenia gravis * skeletal muscle disease * autoimmune disease affecting the neuromuscular junction * nico receptors blocked by antibodies

Question 34

Name two Longer-acting Cholinesterase Inhibitors

Answer 34

1. Physostigmine 2. Neostigmine

Question 35

Physostigmine (Calabar bean) and neostigmine do what

Answer 35

* Bind to cholinesterase to form carbamylated intermediate that hydrolyses in min-hrs * ACh forms acetylated intermediate * Physostigmine and neostigmine are destroyed in reaction

Question 36

Therapeutic Uses of Cholinesterase Inhibitors for the **eye**

Answer 36

* Pupil constricts * ↓Intraocular pressure in **open angle glaucoma** * In **cycloplegia** will contract ciliary muscle, thicken lens and constric pupil and accommodate for near vision

Question 37

Therapeutic Uses of Cholinesterase Inhibitors for the **Skeletal neuromuscular junction**

Answer 37

* Has nicotine receptors * Reverse paralysis caused by curare-like drugs * diagnosis and treatment of myasthenia gravis