Deck 7: Chemical Mediators

Question 1

How many endothelins have been identified so far?

A) One.
B) Two.
C) Three.
D) Four.

Answer 1

Three.

Question 2

Which of the following is not considered a normal physiological role of nitric oxide in the nervous system?

A) The formation of synaptic connections in the developing nervous system.
B) Modulating the release of ACh in the autonomic nervous system.
C) Bronchodilation.
D) Its storage in axon terminals for later release.

Answer 2

Its storage in axon terminals for later release.

Question 3

The following is true of prostaglandins:

A) any prostaglandins that escape into circulation will be destroyed.
B) they act where they are produced, in that they are called a 'local hormone'.
C) they have a very short half-life.
D) all of the above.

Answer 3

all of the above.

Question 4

How is iloprost administered for the treatment of pulmonary hypertension?

A) It is given by continuous intravenous injection through a peripheral venous catheter.
B) It is given by continuous intravenous injection through a central venous catheter.
C) It is given as a continuous subcutaneous infusion.
D) It is given by nebuliser through a mouthpiece.

Question 5

Aside from possible sedation, what other common side effect should individuals be counselled about in their use of 'classic' antihistamines?

A) Urinary retention.
B) Gastrointestinal upset.
C) Dry mouth.
D) All of the above.

Question 6

Which of the following does not act directly as a chemical mediator in cell-to-cell communication?

A) Angiotensin II.
B) Acetylcholine.
C) Cholesterol.
D) Insulin.

Question 7

The general actions of prostaglandins include the following except:

A) inhibition of gastric secretion.
B) stimulation of pancreatic and small intestinal secretions.
C) sensitisation of nerve endings, causing pain.
D) inhibition of release of anterior pituitary hormones .

Question 8

Which of the following is not an effect associated with the endothelins?

A) Vasoconstriction.
B) Vasodilation.
C) Negative inotropic effects.
D) Cellular proliferation.

Question 9

The key difference between autocrine and paracrine secretions is that:

A) autocrine secretions enter the blood and act on neighbouring cells and paracrine secretions remain in the tissues and act locally.
B) paracrine secretions enter the blood and act on neighbouring cells and autocrine secretions remain in the tissues and act locally.
C) autocrine secretions have a more rapid action.
D) paracrine secretions are more potent.

Question 10

Which of the following is a first generation antihistamine?

A) Promethazine.
B) Cetirizine.
C) Loratidine.
D) Fexofenadine.

Question 11

A traditional characteristic of neurocrine transmission has been that neurotransmitters:

A) are released directly into the bloodstream.
B) produce responses slowly.
C) have a prolonged action.
D) interact with short-range targets.

Question 12

Generally when used as drugs, amino acid-based chemical mediators:

A) tend to be a fixed size of about 10-15 residues long.
B) can be administered orally.
C) only influence vascular function.
D) have short half-lives.

Question 13

A cytokine (such as interferon, interleukin and lymphokine) is an example of:

A) a neurotransmitter.
B) a classic hormone.
C) an autacoid.
D) a local hormone.

Question 14

Which of the following is a second generation antihistamine?

A) Fexofenadine.
B) Diphenhydramine.
C) Dimenhydrinate.
D) Promethazine.

Question 15

A human disease that may be associated with excessive nitric oxide production is:

A) diabetes mellitus.
B) atherosclerosis.
C) some forms of cancer.
D) poor wound healing.

Question 16

A paracrine secretion is also known as:

A) an autacoid.
B) a local hormone.
C) a classic hormone.
D) a neurotransmitter.

Question 17

Which of the following peptide mediators is normally involved in enhancing pain transmission?

A) Endorphin.
B) Substance P.
C) Endothelin.
D) Neuropeptide Y.

Question 18

Clients with asthma should avoid antihistamines because:

A) these drugs narrow the airways.
B) these drugs can cause anaphylaxis.
C) these drugs inhibit the activity of β₂ receptor agonists.
D) these drugs increase the thickness of bronchial secretions and dry mucous membranes.

Question 19

Which antihistamine is used in migraine and in stimulating the appetite?

A) Cyproheptadine.
B) Trimprazine.
C) Loratidine.
D) Promethazine.

Question 20

The key difference between the first and second generation antihistamines is that:

A) with second generation antihistamines, lower dosages are required for the same therapeutic effect.
B) second generation medications have more undesirable side effects.
C) the first generation antihistamines are more lipophilic and therefore cross the blood-brain barrier (BBB) causing central nervous system effects.
D) the first generation antihistamines are more lipophobic and therefore cross the blood-brain barrier (BBB) causing central nervous system effects.

Question 21

Which type of histamine receptor, located in the parietal cells of the stomach, is able to trigger gastric acid release upon activation?

A) H₁
B) H₂
C) H₃
D) H₄

Question 22

The endothelins have been implicated in embryonic tissue development.

Question 23

Aside from liver function what other physiological parameters should be monitored regularly during bosentan therapy?

A) Cardiac rhythm and potassium levels.
B) Muscle function and calcium levels.
C) Conscious state and creatinine levels.
D) Blood pressure and haemoglobin levels.

Question 24

Histamine activates H₁ receptors on the endothelium of a venule to cause vasodilation and increased permeability.

Question 25

To maximise the therapeutic effects of antihistamines for motion sickness, they should be taken:

A) when symptoms of nausea and vomiting occur.
B) before the symptoms of nausea and vomiting occur.
C) with milk.
D) in a double dose as soon as symptoms begin.

Question 26

H₁ antihistamines are useful in the management of:

A) peptic ulcers.
B) travel sickness.
C) moderately severe pain.
D) clotting disorders.

Question 27

The number of histamine receptor subtypes that have been identified is:

A) one.
B) two.
C) three.
D) four.

Question 28

Adrenaline can prevent further histamine release in allergic and anaphylactic reactions.

Question 29

Topical use of antihistamines is safe.