Autonomic Nervous System Quiz
50 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which neurotransmitter is primarily released by sympathetic postganglionic neurons?

  • Dopamine
  • Serotonin
  • Acetylcholine
  • Norepinephrine (correct)

What type of receptors do cholinergic neurons interact with?

  • Dopamine receptors
  • Neuropeptide receptors
  • Choline receptors (correct)
  • Adrenergic receptors

Which type of drug mimics the actions of norepinephrine?

  • Cholinomimetic drugs
  • Neuroleptics
  • Sympathomimetics (correct)
  • Parasympathomimetic drugs

Where is acetylcholine released from in the peripheral nervous system?

<p>All parasympathetic postganglionic endings (C)</p> Signup and view all the answers

Which statement best describes the activation of adrenergic receptors?

<p>May lead to either stimulation or inhibition depending on the tissue involved (B)</p> Signup and view all the answers

Which of the following correctly describes adrenergic neurons?

<p>They are noradrenergic or adrenergic. (A)</p> Signup and view all the answers

What effect do some receptor subtypes of the autonomic nervous system generally have on effectors?

<p>Activation may lead to stimulation or inhibition (A)</p> Signup and view all the answers

Which of the following neurotransmitters is released by pre-ganglionic neurons in both the sympathetic and parasympathetic nervous systems?

<p>Acetylcholine (C)</p> Signup and view all the answers

What is the effect of sympathomimetic drugs on heart rate?

<p>Increases heart rate (C)</p> Signup and view all the answers

Which receptor is primarily responsible for bronchodilatation in the respiratory system?

<p>β2 receptor (D)</p> Signup and view all the answers

What happens to vascular resistance at high doses of adrenaline?

<p>Increased due to α1 effects (B)</p> Signup and view all the answers

Which of the following is NOT an effect of sympathomimetic drugs on the gastrointestinal tract?

<p>Increases gastrointestinal motility (B)</p> Signup and view all the answers

What is the main action of β3 receptors in metabolic processes?

<p>Enhance lipolysis (C)</p> Signup and view all the answers

What is the ophthalmic duration of action for cyclopentolate?

<p>24 hours (C)</p> Signup and view all the answers

Which effect does α1 receptor stimulation have in the urinary bladder?

<p>Contracts the sphincter muscle (C)</p> Signup and view all the answers

Why is intravenous adrenaline administered with caution?

<p>It may lead to cardiac arrhythmia (D)</p> Signup and view all the answers

What is the effect of muscarinic activation on heart rate?

<p>Decreases heart rate (A)</p> Signup and view all the answers

Which mechanism primarily mediates generalized vasodilation in blood vessels?

<p>Release of nitric oxide from endothelial lining (A)</p> Signup and view all the answers

What effect does muscarinic activation have on the gastrointestinal tract?

<p>Increases peristaltic activity (D)</p> Signup and view all the answers

Which of the following is NOT caused by muscarinic receptor activation?

<p>Increase in heart rate (D)</p> Signup and view all the answers

What is the role of Mono-Amine Oxidase (MAO) in the termination of adrenergic action?

<p>Oxidative amination of catecholamines (C)</p> Signup and view all the answers

What is the primary therapeutic use of Oxymetazoline?

<p>Nasal decongestant (C)</p> Signup and view all the answers

What effect does muscarinic activation have on sweat glands?

<p>Increases sweating (A)</p> Signup and view all the answers

Which of the following medications selectively stimulates α1 receptors?

<p>Phenylephrine (D)</p> Signup and view all the answers

Which substance is a diagnostic marker for pheochromocytoma related to elevated norepinephrine levels?

<p>Vinylmandelic acid (VMA) (B)</p> Signup and view all the answers

Which effect is associated with the use of Clonidine?

<p>Decreased blood pressure (D)</p> Signup and view all the answers

What is the primary function of the catechol-O-Methyl Transferase (COMT) enzyme?

<p>Degradation of norepinephrine in synapses (D)</p> Signup and view all the answers

What condition is Methoxamine used to treat?

<p>Supraventricular tachycardia (D)</p> Signup and view all the answers

What is the main adverse effect of high doses of Phenylephrine?

<p>Hypertensive headache (A)</p> Signup and view all the answers

Which selective agonist is used to reduce intraocular pressure in open-angle glaucoma?

<p>Brimonidine (D)</p> Signup and view all the answers

What is the primary function of selective β2 agonists?

<p>Relax smooth muscle in bronchioles (A)</p> Signup and view all the answers

Which drug class does Ritodrine belong to?

<p>Tocolytics (B)</p> Signup and view all the answers

What effect does acetylcholine have on the heart via M2 receptors?

<p>Decreases conduction velocity in the AV node (A)</p> Signup and view all the answers

Which effect is primarily associated with M3 receptor activation in smooth muscles?

<p>Increased peristaltic activity in the GIT (D)</p> Signup and view all the answers

What is the primary therapeutic use of bethanechol?

<p>Treatment of atonic bladder (D)</p> Signup and view all the answers

Which statement is true about direct-acting cholinergic agonists?

<p>They have longer durations of action than acetylcholine (A)</p> Signup and view all the answers

Which receptor type is primarily found in skeletal muscle?

<p>NM receptor (C)</p> Signup and view all the answers

What is the effect of acetylcholine on blood vessels?

<p>Generalized vasodilation mediated by nitric oxide (D)</p> Signup and view all the answers

Which of the following is an antagonist of nicotinic receptors?

<p>Tubocurarine (B)</p> Signup and view all the answers

Which glandular secretion is increased by M3 receptor activation?

<p>Increased lacrimal secretion (B)</p> Signup and view all the answers

What is the primary effect of β1 receptor stimulation in the heart?

<p>Increased heart rate (C)</p> Signup and view all the answers

Which sympathomimetic drug is primarily a selective α2 agonist and reduces blood pressure?

<p>Clonidine (A)</p> Signup and view all the answers

What is the effect of low doses of Adrenaline on the vascular system?

<p>Vasodilation predominates (A)</p> Signup and view all the answers

Which drug is known for causing bronchodilatation by activating β2 receptors?

<p>Salmeterol (C)</p> Signup and view all the answers

What indicates the action of Phenylephrine in the peripheral blood vessels?

<p>Vasoconstriction (D)</p> Signup and view all the answers

What is a primary use of Oxymetazoline?

<p>Nasal decongestion (B)</p> Signup and view all the answers

Which sympathomimetic drug is a nonselective β1 and β2 agonist that affects blood pressure?

<p>Isoprenaline (C)</p> Signup and view all the answers

How does Brimonidine affect intraocular pressure in glaucoma?

<p>Decreases aqueous humor production (A)</p> Signup and view all the answers

What describes the characteristic action of Noradrenaline on the vascular system?

<p>Vasoconstriction in most vascular beds (B)</p> Signup and view all the answers

What is a notable side effect of long-acting β2 agonists like Salmeterol?

<p>Increased heart rate (A)</p> Signup and view all the answers

Flashcards

Acetylcholine

The neurotransmitter released by parasympathetic postganglionic neurons, responsible for slowing heart rate and promoting digestion.

Norepinephrine

The neurotransmitter released by most sympathetic postganglionic neurons, responsible for increasing heart rate and regulating blood pressure.

Cholinergic Neurons

Neurons that release acetylcholine. They are found at parasympathetic postganglionic synapses and the neuromuscular junction.

Adrenergic Neurons

Neurons that release norepinephrine. They are found at most sympathetic postganglionic synapses.

Signup and view all the flashcards

Cholinomimetic Drugs

Drugs that mimic the actions of acetylcholine, stimulating the parasympathetic nervous system.

Signup and view all the flashcards

Andromimetic Drugs

Drugs that mimic the actions of norepinephrine, stimulating the sympathetic nervous system.

Signup and view all the flashcards

Choline Receptors

Receptors that bind acetylcholine, found at the neuromuscular junction and parasympathetic postganglionic synapses.

Signup and view all the flashcards

Adrenoceptors

Receptors that bind norepinephrine, found at most sympathetic postganglionic synapses.

Signup and view all the flashcards

Muscarinic Antagonists

A class of drugs that block the actions of acetylcholine, acting as antagonists at muscarinic cholinergic receptors.

Signup and view all the flashcards

Neuromuscular Blocking Agent

A drug that blocks the actions of acetylcholine at the neuromuscular junction, causing muscle paralysis.

Signup and view all the flashcards

Negative Chronotropic Effect

The decrease in heart rate.

Signup and view all the flashcards

Negative Inotropic Effect

The decrease in the force of contraction of the heart.

Signup and view all the flashcards

Negative Dromotropic Effect

The decrease in the conduction velocity of the heart.

Signup and view all the flashcards

Termination of Neurotransmitter Action

The process of removing neurotransmitters from the synaptic cleft.

Signup and view all the flashcards

Catechol-O-Methyltransferase (COMT)

The enzyme that breaks down norepinephrine in the synaptic cleft.

Signup and view all the flashcards

Monoamine Oxidase (MAO)

The enzyme that breaks down norepinephrine within the presynaptic neuron.

Signup and view all the flashcards

What are the major effects of acetylcholine?

Acetylcholine, the neurotransmitter released by parasympathetic postganglionic neurons, has a wide range of effects on the body, including slowing heart rate, increasing digestive activity, and stimulating gland secretions.

Signup and view all the flashcards

How does acetylcholine contribute to vasodilation?

Acetylcholine can cause vasodilation of blood vessels (widening of the blood vessels) by promoting the release of nitric oxide (NO) from the endothelial lining of blood vessels. This contributes to its overall effect of lowering blood pressure.

Signup and view all the flashcards

What are nicotinic receptors and where are they found?

Nicotinic receptors are a type of cholinergic receptor found on skeletal muscle (NM) and in the autonomic ganglia (NN), mediating the effects of acetylcholine.

Signup and view all the flashcards

What are muscarinic receptors and where are they found?

Muscarinic receptors are another type of cholinergic receptor primarily found in the parasympathetic nervous system, responsible for mediating the effects of acetylcholine on smooth muscle, glands, and the heart.

Signup and view all the flashcards

What is bethanechol and how does it work?

Bethanechol is a drug that mimics the effects of acetylcholine by directly activating muscarinic receptors. It's commonly used to treat urinary retention and certain digestive issues.

Signup and view all the flashcards

How does bethanechol help relieve urinary retention?

Bethanechol helps in relieving urinary retention by stimulating the contraction of the detrusor muscle in the bladder, while relaxing the urethral sphincter, allowing urine to pass out.

Signup and view all the flashcards

How does Bethanechol affect gastrointestinal motility?

Bethanechol can increase gastrointestinal motility by stimulating the muscarinic receptors in the digestive tract, helping to move food along.

Signup and view all the flashcards

Why do direct-acting cholinergic drugs have longer durations of actions than acetylcholine?

Direct-acting cholinergic drugs (like bethanechol) have longer durations of action than acetylcholine because they are not broken down as quickly by acetylcholinesterase.

Signup and view all the flashcards

What are sympathomimetic drugs?

Sympathomimetic drugs are a class of medications that mimic the effects of the sympathetic nervous system.

Signup and view all the flashcards

How do sympathomimetic drugs affect the heart?

Sympathomimetic drugs stimulate beta-1 receptors, which are found in the heart, increasing heart rate, contractility, and conductivity.

Signup and view all the flashcards

How do sympathomimetic drugs affect blood vessels?

Sympathomimetic drugs stimulate alpha-1 receptors, causing vasoconstriction in blood vessels of the skin, mucous membranes, kidneys, and gastrointestinal tract.

Signup and view all the flashcards

How do sympathomimetic drugs affect blood vessels (specific)?

Sympathomimetic drugs stimulate beta-2 receptors, causing vasodilation of blood vessels in skeletal muscles and the liver.

Signup and view all the flashcards

How do sympathomimetic drugs affect the respiratory system?

Sympathomimetic drugs stimulate beta-2 receptors, causing relaxation of smooth muscles in the bronchioles, leading to bronchodilation.

Signup and view all the flashcards

Describe the effects of adrenaline on the body.

Adrenaline is a sympathomimetic drug that stimulates both alpha and beta receptors. At lower doses, the beta effects predominate, resulting in vasodilation. At higher doses, the alpha effects predominate, resulting in vasoconstriction.

Signup and view all the flashcards

Describe the effects of noradrenaline on the body.

Noradrenaline is a sympathomimetic drug that primarily stimulates alpha-1 receptors, causing vasoconstriction and increasing blood pressure.

Signup and view all the flashcards

Describe the effects of isoprenaline on the body.

Isoprenaline is a nonselective beta-receptor agonist. It increases cardiac properties and causes vasodilation of coronary and skeletal muscle blood vessels, leading to hypotension.

Signup and view all the flashcards

What are some of the common uses for oxymetazoline?

Oxymetazoline is an alpha-1 and alpha-2 agonist. It is used as a nasal decongestant and to relieve redness of the eyes.

Signup and view all the flashcards

What are some of the common uses for phenylephrine?

Phenylephrine is a selective alpha-1 agonist that is used as a nasal decongestant, mydriatic (pupils dilating), and to induce reflex bradycardia.

Signup and view all the flashcards

Sympathomimetic drugs: General Effects

Sympathomimetic drugs stimulate α1, α2, β1, β2, and β3 receptors, leading to various effects in the cardiovascular system, respiratory system, gastrointestinal system, genitourinary system, eye, and metabolic processes.

Signup and view all the flashcards

Adrenaline: Low Dose Effects

When low doses of adrenaline are administered, β2 receptors are preferentially activated, resulting in vasodilation of blood vessels.

Signup and view all the flashcards

Adrenaline: High Dose Effects

High doses of adrenaline primarily stimulate α1 receptors, leading to vasoconstriction.

Signup and view all the flashcards

Adrenaline: Dose-dependent Effects

The effects of adrenaline are due to its ability to stimulate both α and β receptors, depending on the dose administered.

Signup and view all the flashcards

Adrenaline: Oral Administration

Adrenaline administration via oral route is ineffective due to rapid breakdown by digestive enzymes and liver metabolism.

Signup and view all the flashcards

Adrenaline: Subcutaneous Administration

Subcutaneous administration of adrenaline is slow due to local vasoconstriction caused by the drug itself.

Signup and view all the flashcards

Adrenaline: Intramuscular Administration

Intramuscular injection of adrenaline leads to more rapid absorption due to β2-mediated vasodilatation at the site of injection.

Signup and view all the flashcards

Adrenaline: Intravenous Administration

Intravenous administration of adrenaline must be done with caution to avoid cardiac arrhythmias, such as fibrillation.

Signup and view all the flashcards

What is a drug that increases AV node conduction velocity with minimal impact on heart rate and is used to treat congestive heart failure?

A drug that increases AV node conduction velocity with minimal impact on heart rate, used to treat congestive heart failure (CHF) by intravenous infusion.

Signup and view all the flashcards

What is Oxymetazoline used for?

A selective α1 agonist used as a nasal decongestant, relieving redness of the eyes caused by swimming, colds, or contact lenses.

Signup and view all the flashcards

What is Phenylephrine used for and what's its effect on heart rate?

A selective α1 agonist used as a nasal decongestant and a mydriatic (pupil dilator). It induces reflex bradycardia when administered intravenously, but it doesn't directly affect the heart.

Signup and view all the flashcards

What is Methoxamine used for and how does it affect blood pressure and heart rate?

A selective α1 agonist that directly stimulates α1 receptors in arterioles, leading to increased blood pressure and heart rate. Used to treat supraventricular tachycardia and reverse hypotension during surgery.

Signup and view all the flashcards

How does Clonidine work and what is it used for?

Clonidine is a central α2 agonist that reduces sympathetic outflow to the periphery, lowering blood pressure. Used for treating essential hypertension and opioid withdrawal symptoms.

Signup and view all the flashcards

What is Brimonidine used for and how does it work?

Brimonidine is a selective α2 agonist used topically in the eye to decrease intraocular pressure (IOP) in open-angle glaucoma by reducing aqueous humor production and increasing outflow.

Signup and view all the flashcards

What are the differences between short-acting and long-acting β2 agonists and how are they used?

Short-acting β2 agonists like salbutamol and terbutaline cause bronchodilation with minimal effect on the heart and are delivered via inhalers. Long-acting β2 agonists like salmeterol and formoterol provide sustained bronchodilation for longer periods and are used for nocturnal asthma.

Signup and view all the flashcards

What is Ritodrine used for?

Ritodrine is a tocolytic drug (uterine relaxant) that inhibits uterine contractions in premature labor, helping prevent premature birth.

Signup and view all the flashcards

Study Notes

Pharmacology 1

  • This course is all automatic.
  • The course is part of the Faculty of Dentistry, Alryada University.

Autonomic Nervous System

  • The autonomic nervous system (ANS) is part of the nervous system.
  • It controls involuntary functions.
  • It is composed of the sympathetic and parasympathetic divisions.

Nervous System (N.S)

  • The nervous system has two main divisions:
    • Central Nervous System (CNS)
      • Brain
      • Spinal cord
    • Peripheral Nervous System (PNS)
      • Nerves
        • Sensory (afferent) division: transmits signals from sensory receptors to the CNS.
        • Motor (efferent) division: transmits signals from the CNS to effector organs (muscles and glands).
          • Somatic Nervous System (SNS): controls voluntary movements of skeletal muscles.
          • Autonomic Nervous System (ANS): controls involuntary functions of smooth and cardiac muscles, glands, and some visceral organs.
            • Sympathetic division: often associated with "fight or flight" responses.
            • Parasympathetic division: often associated with "rest and digest" responses.
  • The divisions of the ANS work antagonistically, one tends to oppose another, to maintain homeostasis.
  • The SNS uses a single neuron pathway that is heavily myelinated from CNS to skeletal muscle, using acetylcholine.
  • The ANS, sympathetic, uses two neuron pathways (one preganglionic and the other postganglionic), lightly myelinated from the brain/spinal cord to preganglionic neurons. Then to ganglion and the postganglionic neuron to the target tissue.

Nervous System (N.S), further details

  •  Sympathetic - heavily myelinated with acetylcholine

  • ANS uses two-neuron chain that is lightly myelinated with acetylcholine or norepinephrine, including the following

  •  Preganglionic Neuron → Ganglion → Postganglionic Neuron → Target tissue

  • Adrenal glands release epinephrine into the blood which also effects the target tissue, which is a different route from acetylcholine

  • Sympathetic = Fight or flight

  • Parasympathetic = Rest and digest

  • The target organ is the effector organ.

Autonomic Ganglia

  • Ganglia are sites where information (action potentials) from the CNS are transmitted to the periphery via synaptic neurotransmission.
  • The information from the CNS can be amplified, inhibited, or left unaltered at the ganglia.

Sympathetic Ganglia & Parasympathetic Ganglia

  • Sympathetic - located in two chains, paravertebral ganglia on each side of vertebral bodies. Postganglionic neurons are long, to reach multiple targets via spinal nerves.
  • Parasympathetic - located within the target organ. Pre and postganglionic neurons are shorter due to the ganglia located within the target tissue.

Autonomic Neurotransmitters

  • The functional difference between sympathetic & parasympathetic postganglionic neurons is due to the different neurotransmitters each uses:
    • Acetylcholine.
    • Norepinephrine.

Sites of ACh release

  • All preganglionic autonomic ganglia (sympathetic & parasympathetic)
  • All postganglionic parasympathetic nerve endings.
  • Somatic nerve of skeletal muscle (End motor plate, NMJ)
  • Sweat glands, adrenal medulla, BV's of some skeletal muscles (sympathetic nerve only)

Receptors of the ANS

  • A particular receptor subtype for each division of the ANS will dominate in a certain gland or organ.
  • In general, activation of some receptor subtypes leads to stimulation of the effector, and activation of others to inhibition of the effector.

Adrenergic Receptors

  • Epinephrine (EPI) released by the adrenal gland also binds to adrenergic receptors expressed on effectors.
  • There are two main types of adrenergic receptors, namely, alpha and beta which have multiple subtypes.
  • Activation of adrenergic receptors by NE or EPI may result in stimulation or inhibition of the effector depending on the tissue involved.
  • Odd subtypes (α1, β1, β3) generally have stimulatory effects, while even subtypes (α2, β2) have inhibitory effects.

Effector Organs with Sympathetic and Parasympathetic effects

  • Detailed table of sympathetic and parasympathetic effects on specific organs, including receptor types involved.

Blood vessels

  • Sympathetic division regulates tension produced by vascular smooth muscle ↑ blood pressure via action on alpha-adrenoceptors.
  • No parasympathetic innervation EXCEPT some sexual organs' erectile tissues.

The Heart, further details

  • Sympathetic: Accelerate the heart rate (tachycardia). Positive inotropic effect, increase stroke volume . β1 receptors involved
  • Parasympathetic: Slow the heart (bradycardia). Acetylcholine used, muscarinic receptors involved.

Respiratory Tract

  • Sympathetic: Dilate the airways (mediated by β2 adrenoreceptors), and vasoconstrictor
  • Parasympathetic: Produce bronchoconstriction (mediated by muscarinic receptors), and vasodilator.

Gastrointestinal Tract

  • Sympathetic: Inhibitory on gastric smooth muscle
  • Parasympathetic: Stimulatory on smooth muscles (increase motility), ↑ acid secretion, stimulatory(contract) sphincters
  • Parasympathetic is stimulatory, and sympathetic is inhibitory, for this organ

Synthesis, Storage, Release, and Removal of Acetylcholine

  • Detailed diagram and description of the process.

Synthesis, Storage, Release, and Removal of Norepinephrine

  • Detailed diagram and description of the process.

Muscarinic receptors

  • Detailed table of subtype, location, and actions of specific M1, M2, M3, M4, M5 receptors

Nicotinic receptors

  • Table clarifying the locations where each type of nicotinic receptor is found.

Sites of ACh release

  • All preganglionic autonomic ganglia (both sympathetic and parasympathetic)
  • All postganglionic parasympathetic nerve endings
  • Somatic nerves in skeletal muscle (end motor plate, NMJ)
  • Exceptions: Sympathetic nerves to sweat glands, adrenal medulla, BVs in some skeletal muscles.

Sympathetic Nervous System, acting drugs

  • Detailed analysis of the different types of sympathetic acting drugs.

Parasympathetic Nervous System, acting drugs

  • Detailed analysis of the different types of parasympathetic acting drugs.

Pharmacological Actions of specific drugs

  • Detailed actions of Cholinergic and Adrenergic drugs. Including uses, side effects and contraindications

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Pharmacology 1 Lecture Notes PDF

Description

Test your knowledge on the autonomic nervous system, covering key neurotransmitters, receptors, and the functions of sympathetic and parasympathetic neurons. This quiz will challenge your understanding of how these systems interact and their physiological effects.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser