Xerostomia and Salivary Glands Quiz

Questions and Answers

What is the primary action of depolarizing blocking agents on muscle fibers?

They inhibit ACh release at the neuromuscular junction.

They depolarize the plasma membrane of the muscle fiber. (correct)

They polarize the membrane, leading to muscle relaxation.

They enhance the degradation by AChE.

Why is succinylcholine particularly useful for rapid endotracheal intubation?

It causes permanent muscle paralysis.

It has a rapid onset and short duration of action. (correct)

It has a long duration of action.

It acts slowly, providing time for preparation.

How does succinylcholine differ from ACh regarding degradation?

Succinylcholine requires a higher dosage than ACh.

ACh is more effective at depolarization than succinylcholine.

Succinylcholine resists degradation by AChE. (correct)

Succinylcholine is rapidly degraded by AChE.

In which scenario is succinylcholine NOT typically utilized?

Long-term muscle paralysis. Signup and view all the answers

What is the only depolarizing muscle relaxant currently in use?

Succinylcholine Signup and view all the answers

What condition is indicated by involuntary voiding of urine?

Enuresis Signup and view all the answers

What effect do a-adrenergic agonists have on secretions?

They reduce secretions. Signup and view all the answers

What can inhibit secretions by sweat glands lead to?

Elevated body temperature Signup and view all the answers

What is a significant risk of using atropine in older individuals?

Exacerbation of glaucoma Signup and view all the answers

What condition is commonly associated with drying oral mucous membranes?

Xerostomia Signup and view all the answers

How does scopolamine differ from atropine in terms of CNS effects?

Scopolamine shows CNS effects at therapeutic doses Signup and view all the answers

What therapeutic use is particularly effective for scopolamine?

Prevention of motion sickness Signup and view all the answers

Which population could be particularly at risk due to elevated body temperature from inhibited sweat glands?

Children and elderly Signup and view all the answers

What unusual effect can scopolamine have on memory?

Induction of amnesia Signup and view all the answers

Which of the following is a therapeutic use mentioned for cholinergic antagonists?

Ophthalmic purposes Signup and view all the answers

Which glands are similarly affected by secretions reduction aside from salivary glands?

Sweat and lacrimal glands Signup and view all the answers

Why is codeine considered less effective when treating motion sickness compared to scopolamine?

Codeine does not block acetylcholine Signup and view all the answers

What side effect is often associated with a-adrenergic agonists?

Dry mouth Signup and view all the answers

Which of the following is a dangerous effect of atropine in children?

Rapid increase in body temperature Signup and view all the answers

How does scopolamine affect the vestibular system?

Blocks communication with the vomiting center Signup and view all the answers

What effect can high doses of scopolamine produce?

Increased euphoria Signup and view all the answers

What is a primary use of atropine in emergency situations?

As an antidote for cholinergic agonist overdoses Signup and view all the answers

Which of the following is a common adverse effect associated with atropine administration?

Blurred vision Signup and view all the answers

Why might shorter-acting antimuscarinics replace atropine in clinical settings?

Atropine causes prolonged mydriasis Signup and view all the answers

What is one of the therapeutic effects of atropine when used as an antispasmodic agent?

Blocks secretions in the respiratory tract Signup and view all the answers

Which condition could potentially be exacerbated by the use of atropine?

Narrow-angle glaucoma Signup and view all the answers

What role does atropine play in the treatment of mushroom poisoning?

It blocks the effects of excess acetylcholine Signup and view all the answers

Which pharmacological action defines atropine's use as an antispasmodic agent?

Relaxation of the GI tract and bladder Signup and view all the answers

What serious adverse effect can result from inappropriate dosing of atropine?

Collapse of the circulatory and respiratory systems Signup and view all the answers

What is the primary action of oxybutynin on the bladder?

Lowers intra vesicular pressure Signup and view all the answers

What is a notable advantage of the transdermal system of oxybutynin compared to oral formulations?

Causes less dry mouth Signup and view all the answers

What is the primary reason ganglionic blockers are rarely used therapeutically?

They block the entire output of the autonomic nervous system Signup and view all the answers

Which type of receptor do ganglionic blockers primarily target?

Nicotinic receptors Signup and view all the answers

How does oxybutynin affect bladder capacity?

It increases bladder capacity Signup and view all the answers

Which of the following statements about ganglionic blockers is true?

They block both the sympathetic and parasympathetic systems. Signup and view all the answers

What is the mechanism by which oxybutynin reduces bladder contractions?

Blocking muscarinic receptors Signup and view all the answers

What effect do cholinergic antagonists like oxybutynin have on the autonomic nervous system?

Block neurotransmission at various receptors Signup and view all the answers

Study Notes

Secretions and Effects

Salivary glands may reduce secretions, influenced by dose, which can lead to xerostomia (dry mouth).
Hypermotility states can affect urinary bladder function, potentially causing enuresis (involuntary urination).
Alpha-adrenergic agonists can manage these conditions with fewer side effects but may lead to increased body temperature if sweat gland secretions are inhibited, posing higher risks for children and elderly.

Therapeutic Uses of Antimuscarinics

Ophthalmic Use:
- Atropine is used to measure refractive errors but can lead to acute eye pain due to pressure increases in narrow-angle glaucoma.
- Short-acting antimuscarinics like cyclopentolate and tropicamide are preferred to avoid prolonged mydriasis.
Antispasmodic Effect:
- Atropine, specifically l-hyoscyamine, is effective for relaxing the GI tract and bladder for antispasmodic purposes.
Antidote for Cholinergic Overdose:
- Useful against cholinesterase inhibitor insecticide overdoses and specific mushroom poisonings, blocking the effects of acetylcholine.
Antisecretory Properties:
- Employed to decrease secretions in respiratory tracts prior to surgery, mitigating effects of excess ACh.

Adverse Effects of Atropine

Common side effects include dry mouth, blurred vision, tachycardia, urinary retention, and constipation.
CNS-related issues can manifest as restlessness, confusion, hallucinations, or severe outcomes like respiratory collapse and death.
Elderly patients face heightened risks, particularly concerning glaucoma and urinary retention.
Children are especially sensitive, with risks including fever from rapid temperature increases.

Scopolamine Overview

Scopolamine mirrors atropine's peripheral effects but has more pronounced CNS actions, which occur at therapeutic doses.
Effective for preventing motion sickness and blocking short-term memory, it alters communication to the vomiting center in the brain.
Sedative effects are noted, with possible excitement at higher doses, and potential for misuse due to euphoria.

Oxybutynin and Its Functions

Blocks muscarinic receptors in the bladder, leading to lowered intra-vesicular pressure and increased bladder capacity.
Available as a topical patch, which is better tolerated, causing less dry mouth than oral formulations.

Ganglionic Blockers

These agents lack selectivity for autonomic ganglia and do not function as neuromuscular blockers, impacting both sympathetic and parasympathetic systems.
Rarely used therapeutically, they're primarily found in experimental pharmacology settings.

Depolarizing Agents

Agents like succinylcholine induce muscle fiber depolarization mimicking ACh but have resistance to degradation by AChE, leading to sustained effects.
Rapid onset and short duration make succinylcholine valuable for quick endotracheal intubation and during electroconvulsive therapy.

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Description

Test your understanding of xerostomia, the condition characterized by dry oral mucous membranes due to reduced salivary secretions. This quiz will cover the functions of salivary glands and the effects of hypermotility and dosage. Assess your knowledge on urinary and oral health connections.