AUTONOMIC NERVOUS SYSTEM DRUGS EXAM

Pharmacology I - Day 5 Examination

Examination No:

Signature:

For Examiner's Use Only
Section	Question	Result	Initials
A	MCQs
A	Fill in
B	31-32
C	33-35
Total

IMPORTANT

Answer all the questions in the provided answer booklet.
Read the questions carefully and answer only what has been asked.
This paper has three sections: A, B, and C.

SECTION A: OBJECTIVE QUESTIONS (40 MARKS)

Multiple Choice Questions (Circle the correct answer in your answer booklet) (20 Marks)

The "fight-or-flight" response is mediated by which division of the autonomic nervous system?

(a) Somatic

(b) Parasympathetic

(d) Central

Which neurotransmitter is released by all preganglionic autonomic neurons?

(a) Norepinephrine

(b) Dopamine

(d) Acetylcholine

A drug described as a "sympathomimetic" would be expected to cause:

(a) Decreased heart rate

(b) Bronchoconstriction

(d) Increased salivation

The nicotinic receptor found at the skeletal neuromuscular junction is specifically the:

(a) Nn (neuronal) type

(b) Nm (muscle) type

(d) M2 type

A patient is given a drug that blocks muscarinic receptors. Which of the following effects would you expect to see?

(a) Bradycardia (slow heart rate)

(b) Increased salivation

(d) Bronchoconstriction

The primary neurotransmitter released by postganglionic sympathetic neurons is:

(a) Acetylcholine

(b) Norepinephrine

(d) Serotonin

Stimulation of which adrenergic receptor subtype causes relaxation of bronchial smooth muscle (bronchodilation)?

(a) Alpha-1

(b) Alpha-2

(d) Beta-2

The "rest-and-digest" functions are the primary responsibility of which system?

(a) Sympathetic

(b) Parasympathetic

(d) Endocrine

A drug classified as a "parasympatholytic" would also be known as a(n):

(a) Adrenergic agonist

(b) Cholinergic agonist

(d) Cholinergic blocker (anticholinergic)

10.

Which of the following organs receives ONLY sympathetic innervation?

(a) The heart

(b) The urinary bladder

(d) The salivary glands

11.

Stimulation of M₂ muscarinic receptors in the heart would cause:

(a) Increased heart rate

(b) Increased force of contraction

(d) Vasoconstriction

12.

A patient receives an overdose of a sympathomimetic drug like epinephrine. Which of the following signs would be expected?

(a) Constricted pupils

(b) Low blood pressure

(d) Increased GIT motility

13.

The receptors located in all autonomic ganglia (both sympathetic and parasympathetic) are:

(a) Muscarinic receptors

(b) Nicotinic-neuronal (Nn) receptors

(d) Adrenergic receptors

14.

Which of the following is an effect of the parasympathetic nervous system?

(a) Dilation of pupils

(b) Relaxation of bronchi

(d) Ejaculation

15.

Stimulation of which adrenergic receptor is primarily responsible for increasing heart rate and force of contraction?

(a) Alpha-1

(b) Alpha-2

(d) Beta-2

16.

The adrenal medulla functions most like a modified:

(a) Parasympathetic ganglion

(b) Sympathetic ganglion

(d) Sensory neuron

17.

Stimulation of M₃ muscarinic receptors would lead to all of the following EXCEPT:

(a) Increased salivation

(b) Contraction of the urinary bladder

(d) Increased heart rate

18.

A drug that blocks the effects of the sympathetic nervous system is called a:

(a) Sympathomimetic

(b) Parasympathomimetic

(d) Parasympatholytic

19.

Activation of α₁ adrenergic receptors on blood vessels causes:

(a) Vasodilation

(b) Vasoconstriction

(d) Increased permeability

20.

A patient is given Atropine, a parasympatholytic, before surgery. This drug is expected to cause:

(a) Increased bronchial secretions and bradycardia

(b) Decreased bronchial secretions and tachycardia

(d) Bronchoconstriction and hypotension

Fill in the Blank Spaces (Write the correct answer in your answer booklet) (20 Marks)

21. Drugs that mimic the effects of the parasympathetic nervous system are called .

22. The two main classes of cholinergic receptors are nicotinic and .

23. The "fight or flight" response is primarily driven by the nervous system.

24. The receptor found on all effector organs of the parasympathetic system is the receptor.

25. A drug that blocks adrenergic receptors is known as a(n) .

26. The primary neurotransmitter of the parasympathetic nervous system at the effector organ is .

27. Stimulation of β₂ adrenergic receptors causes relaxation of bronchial and smooth muscle.

28. The two main classes of adrenergic receptors are alpha and .

29. The nicotinic receptor found in autonomic ganglia is the subtype.

30. A drug that mimics the actions of norepinephrine at adrenergic receptors is called a(n) .

SECTION B: SHORT ESSAY QUESTIONS (20 MARKS)

31.

(a) State the two main divisions of the Autonomic Nervous System (ANS). (2 Marks)

(b) For each division, state its general function (e.g., "fight-or-flight") and the primary neurotransmitter it releases at the effector organ. (8 Marks)

32.

(a) Name the two main types of cholinergic receptors. (4 Marks)

(b) Where is each receptor type primarily located in the peripheral nervous system? (6 Marks)

SECTION C: LONG ESSAY QUESTIONS (40 MARKS)

33. Most organs have dual innervation from the ANS, with the two divisions having opposing effects.

(a) Describe the opposing effects of the sympathetic and parasympathetic nervous systems on the following three organs: (i) The heart, (ii) The bronchi, and (iii) The pupil of the eye. (9 Marks)

(b) What is this type of interaction called, where two systems produce opposing physiological outcomes? (3 Marks)

(c) Name one major organ system that receives almost exclusively sympathetic innervation. (4 Marks)

34.

A patient with asthma is prescribed Salbutamol, a selective β₂-agonist, to be used during an asthma attack. A different patient with hypertension and angina is prescribed Propranolol, a non-selective β-blocker.

(a) Explain the mechanism by which Salbutamol provides relief during an asthma attack, specifying the receptor and the resulting physiological effect. (6 Marks)

(b) Explain the mechanism by which Propranolol helps manage hypertension, specifying the receptor and physiological effect on the heart. (6 Marks)

(c) Why would it be dangerous to give the non-selective β-blocker Propranolol to the asthmatic patient? (6 Marks)

Question 35. The pharmacology of the parasympathetic nervous system revolves around cholinergic receptors.

(a) Name the three main subtypes of muscarinic receptors (M1, M2, M3) and state a primary location for each. (6 Marks)

(b) A patient is given Atropine, a muscarinic antagonist (parasympatholytic). Describe two expected effects on the body and the receptor subtype responsible for each effect. (6 Marks)

(c) What is the difference between a sympathomimetic drug and a parasympatholytic drug, even though both can cause an increased heart rate? (4 Marks)

END

Marking Guide - Pharmacology I - Day 5

SECTION A: OBJECTIVE QUESTIONS (40 MARKS)

Multiple Choice Questions (1 Mark Each)

1. (c) Sympathetic.

Rationale: The sympathetic nervous system prepares the body for stressful situations requiring immediate action.

2. (d) Acetylcholine.

Rationale: Acetylcholine (ACh) is the neurotransmitter for ALL preganglionic neurons (both sympathetic and parasympathetic) and acts on nicotinic receptors in the ganglia.

3. (c) Increased heart rate and blood pressure.

Rationale: A sympathomimetic drug mimics the "fight-or-flight" response, which includes increasing heart rate (tachycardia) and constricting blood vessels to raise blood pressure.

4. (b) Nm (muscle) type.

Rationale: The Nm receptor is found on skeletal muscle. The Nn (neuronal) receptor is found in autonomic ganglia.

5. (c) Mydriasis (pupil dilation).

Rationale: Parasympathetic stimulation constricts the pupil (miosis) via M₃ receptors. Blocking these receptors allows the sympathetic system's effect (dilation) to dominate. The other options are parasympathetic effects that would be blocked, not caused.

6. (b) Norepinephrine.

Rationale: Norepinephrine (noradrenaline) is the primary transmitter for most postganglionic sympathetic fibers. The exception is sweat glands, which use ACh.

7. (d) Beta-2.

Rationale: β₂ receptors are predominantly found on non-vascular smooth muscle like the bronchi and uterus, and their stimulation causes relaxation.

8. (b) Parasympathetic.

Rationale: The parasympathetic system is responsible for conserving energy and overseeing routine functions like digestion and resting.

9. (d) Cholinergic blocker (anticholinergic).

Rationale: "Lytic" means to block or inhibit. A parasympatholytic blocks the parasympathetic system, which is a cholinergic system. Therefore, it is a cholinergic blocker.

10. (c) Most blood vessels.

Rationale: The tone of most blood vessels is controlled exclusively by the sympathetic nervous system. The other organs have dual innervation.

11. (c) Decreased heart rate.

Rationale: M₂ receptors are the primary muscarinic subtype in the heart. Their stimulation mimics the effect of the vagus nerve, slowing down the heart rate (bradycardia).

12. (c) Tachycardia (rapid heart rate).

Rationale: A sympathomimetic overdose would cause an extreme "fight-or-flight" response, including a very rapid heart rate due to β₁ stimulation.

13. (b) Nicotinic-neuronal (Nn) receptors.

Rationale: Acetylcholine acts on Nn receptors on all postganglionic neurons to transmit the signal from the preganglionic neuron.

14. (c) Increased GIT motility and secretion.

Rationale: This is a key "rest-and-digest" function of the parasympathetic system. The other options are sympathetic effects.

15. (c) Beta-1.

Rationale: β₁ receptors are primarily located in the heart, and their stimulation increases heart rate, contractility, and conduction velocity.

16. (b) Sympathetic ganglion.

Rationale: The adrenal medulla is derived from the same embryonic tissue as postganglionic sympathetic neurons and releases catecholamines (epinephrine, norepinephrine) directly into the blood.

17. (d) Increased heart rate.

Rationale: Increased heart rate is a sympathetic (β₁) effect. M₃ stimulation causes increased glandular secretions (salivation), contraction of smooth muscle (bladder, bronchi), but heart rate is decreased via M₂ receptors.

18. (c) Sympatholytic.

Rationale: "Lytic" means to block or inhibit. A sympatholytic drug blocks the sympathetic nervous system.

19. (b) Vasoconstriction.

Rationale: α₁ receptors are primarily located on vascular smooth muscle, and their stimulation by norepinephrine causes contraction, leading to vasoconstriction and increased blood pressure.

20. (b) Decreased bronchial secretions and tachycardia.

Rationale: Atropine blocks parasympathetic effects. It will block M₃ receptors, decreasing secretions, and block M₂ receptors on the heart, leading to an unopposed sympathetic tone and an increased heart rate (tachycardia).

Fill in the Blank Spaces (2 Marks Each)

21. parasympathomimetics (or cholinomimetics)

Rationale: These drugs mimic the "rest-and-digest" actions of acetylcholine.

22. muscarinic

Rationale: These are the two main receptor types that bind acetylcholine.

23. sympathetic

Rationale: This system prepares the body for stress.

24. muscarinic

Rationale: Postganglionic parasympathetic fibers release ACh, which acts on muscarinic receptors on effector organs like the heart, GIT, and bladder.

25. sympatholytic (or adrenergic blocker)

Rationale: These drugs block the effects of the sympathetic nervous system.

26. acetylcholine (ACh)

Rationale: The parasympathetic system is cholinergic at both the ganglion and the effector organ.

27. uterine

Rationale: β₂ stimulation causes relaxation of non-vascular smooth muscle, which includes the bronchi and the uterus.

28. beta

Rationale: These are the two main families of receptors that bind norepinephrine and epinephrine.

29. Nn (neuronal)

Rationale: The Nn subtype is found on postganglionic neurons, while the Nm subtype is found on skeletal muscle.

30. sympathomimetic (or adrenergic agonist)

Rationale: "Mimetic" means to mimic. These drugs mimic the effects of the sympathetic nervous system.

SECTION B: SHORT ESSAY QUESTIONS (20 MARKS)

Question 31 (10 Marks)

(a) State the two main divisions of the Autonomic Nervous System. (2 Marks)

Sympathetic Nervous System
Parasympathetic Nervous System

(b) For each division, state its general function and primary neurotransmitter. (8 Marks)

Sympathetic (4 marks): General function is "fight-or-flight," preparing the body for stress and activity. The primary neurotransmitter at the effector organ is Norepinephrine (noradrenaline).

Parasympathetic (4 marks): General function is "rest-and-digest," conserving energy and overseeing routine functions. The primary neurotransmitter at the effector organ is Acetylcholine.

Question 32 (10 Marks)

(a) Name the two main types of cholinergic receptors. (4 Marks)

Nicotinic receptors
Muscarinic receptors

(b) Where is each receptor type primarily located? (6 Marks)

Nicotinic receptors (3 marks): Primarily located in all autonomic ganglia (Nn subtype) and at the skeletal neuromuscular junction (Nm subtype).

Muscarinic receptors (3 marks): Primarily located on all effector organs innervated by postganglionic parasympathetic neurons (e.g., heart, smooth muscle, glands).

SECTION C: LONG ESSAY QUESTIONS (40 MARKS)

Question 33: Dual Innervation. (16 Marks)

(a) Describe the opposing effects on the heart, bronchi, and pupil. (9 Marks)

Heart (3 marks): Sympathetic increases heart rate and contractility. Parasympathetic decreases heart rate.

Bronchi (3 marks): Sympathetic causes bronchodilation (relaxation of smooth muscle). Parasympathetic causes bronchoconstriction (contraction of smooth muscle).

Pupil (3 marks): Sympathetic causes pupillary dilation (mydriasis). Parasympathetic causes pupillary constriction (miosis).

(b) What is this type of interaction called? (3 Marks)

This is called Physiological Antagonism, where two systems produce opposing effects through different receptors and pathways.

Most blood vessels (arterioles and veins) / Adrenal Medulla / Spleen / Piloerector muscles / Sweat glands.

Question 34: Scenario - Adrenergic Drugs. (18 Marks)

(a) Explain the mechanism of Salbutamol in asthma. (6 Marks)

Salbutamol is a selective β₂-agonist. (2 marks) It binds to and stimulates β₂-adrenergic receptors located on the smooth muscle of the bronchi. (2 marks) Activation of these receptors leads to smooth muscle relaxation, resulting in bronchodilation and relief from the asthma attack. (2 marks)

(b) Explain the mechanism of Propranolol in hypertension. (6 Marks)

Propranolol is a β-antagonist (blocker). (2 marks) It blocks β₁-adrenergic receptors in the heart. (2 marks) This prevents the effects of norepinephrine/epinephrine, leading to a decrease in heart rate and force of contraction, which reduces cardiac output and helps lower blood pressure. (2 marks)

Propranolol is a non-selective β-blocker, meaning it blocks both β₁ and β₂ receptors. (3 marks) If given to an asthmatic patient, it will block the β₂ receptors in the bronchi. This would prevent bronchodilation and could lead to severe, life-threatening bronchoconstriction. (3 marks)

Question 35. Cholinergic Pharmacology. (16 Marks)

(a) Name the three main muscarinic subtypes (M1, M2, M3) and a primary location for each. (6 Marks)

Rationale: Award 2 marks for each correct pairing.

M₁: CNS / GIT (enteric nerves)
M₂: Heart (cardiac muscle)
M₃: Exocrine glands / Smooth muscle (e.g., bladder, bronchi)

(b) Describe two expected effects of Atropine and the receptor responsible. (6 Marks)

Rationale: Award 3 marks for each correct effect with receptor.

Effect 1: Tachycardia (increased heart rate). This is due to the blockade of M₂ receptors on the heart, which removes the normal "braking" effect of the parasympathetic system.

Effect 2: Dry mouth / Decreased secretions. This is due to the blockade of M₃ receptors on the salivary and other exocrine glands.

(Other valid answers include pupil dilation/mydriasis, urinary retention, etc.)

A sympathomimetic (e.g., epinephrine) increases heart rate by directly activating β₁ adrenergic receptors on the heart, stimulating it to beat faster ("pressing the accelerator"). (2 marks)

A parasympatholytic (e.g., atropine) increases heart rate by blocking M₂ muscarinic receptors on the heart. This removes the normal inhibitory (slowing) effect of the parasympathetic system, allowing the heart rate to rise ("taking the foot off the brake"). (2 marks)

END OF MARKING GUIDE

NURSES REVISION INSTITUTE OF HEALTH SCIENCES

CONTINUOUS ASSESSMENT TEST

IMPORTANT

SECTION A: OBJECTIVE QUESTIONS (40 MARKS)

SECTION B: SHORT ESSAY QUESTIONS (20 MARKS)

SECTION C: LONG ESSAY QUESTIONS (40 MARKS)

NURSES REVISION INSTITUTE - MARKING GUIDE

PHARMACOLOGY: AUTONOMIC NERVOUS SYSTEM