Autonomic Nervous System Quiz

Questions and Answers

What happens to neurotransmitter agents after they bind to membrane receptors on effectors?

They elicited a physiologic response and are subsequently deactivated. (correct)

They are taken back into the axon terminal without any effect.

They are rapidly destroyed by enzymes.

They remain permanently bound to the receptors.

What role do enzymes play in the process of neurotransmitter action?

Enzymes promote the binding of neurotransmitters to receptors.

Enzymes regenerate neurotransmitters for future use.

Enzymes are involved in releasing neurotransmitters into the synaptic cleft.

Enzymes destroy neurotransmitters at the synaptic cleft to terminate their effects. (correct)

Which of the following statements is true regarding the interaction between neurotransmitters and receptors?

Neurotransmitters must be present indefinitely to elicit a response.

Neurotransmitters bind irreversibly to receptors.

Receptors can only interact with one type of neurotransmitter.

Neurotransmitters detach after eliciting a physiologic response. (correct)

Where does the enzymatic deactivation of neurotransmitters primarily occur?

At the synaptic cleft near the receptors. Signup and view all the answers

What is the physiological role of neurotransmitter agents in synaptic transmission?

To bind with receptors and trigger a response in effectors. Signup and view all the answers

What initiates the generation of a sensory impulse in the chemoreceptors of the mouth?

The chemical composition of food Signup and view all the answers

Which type of nerve fiber transmits sensory impulses from sensory receptors to the central nervous system?

Afferent nerve fibers Signup and view all the answers

What role does the spinal cord play after receiving a sensory impulse?

It transmits motor impulses to the smooth muscle Signup and view all the answers

What is the function of the effector cell in the autonomic nervous system?

To respond to impulses by performing a specific action Signup and view all the answers

Which statement correctly describes the process of a sensory impulse reaching the spinal cord?

It involves the conversion of receptor potential into an action potential Signup and view all the answers

What happens to the smooth muscle in response to a motor impulse from the spinal cord?

It contracts to move retained food Signup and view all the answers

Which component of the nervous system is primarily responsible for interpreting sensory impulses?

Central nervous system Signup and view all the answers

What is the initial response of mechanoreceptors to retained food in the small intestine?

Creating a sensory impulse that is sent to the spinal cord Signup and view all the answers

What is the primary action of parasympatholytic drugs?

Block cholinergic effects Signup and view all the answers

Which of the following is an example of a sympathomimetic drug?

Phenylephrine Signup and view all the answers

What effect does atropine have when administered intravenously?

Dilation of pupil Signup and view all the answers

How do sympatholytic drugs primarily affect the sympathetic nervous system?

Block the release of norepinephrine Signup and view all the answers

What is the mechanism of action for sympathomimetic drugs?

Increase the release of norepinephrine Signup and view all the answers

Which effect is associated with the administration of salbutamol?

Bronchodilation Signup and view all the answers

Which autonomic activity can be mostly involuntary but also partly voluntary?

Respiration Signup and view all the answers

What physiological response occurs due to the action of sympathomimetic agents like adrenaline?

Dilation of pupils Signup and view all the answers

Which statement is true regarding the autonomic centers within the cortex?

There is no localized autonomic center in the cortex Signup and view all the answers

What is the primary function of Auerbach's Plexus in the enteric nervous system?

Regulating motor activity of the gastrointestinal tract Signup and view all the answers

What initiates the autonomic reflex for defecation?

Rectal pressure reaching 55mmHg Signup and view all the answers

In the autonomic nervous system, what is the effect of sympathetic postganglionic fibers on enteric neurons?

They inhibit GIT motor activity Signup and view all the answers

Which plexus is primarily involved in regulating secretory activity of the gastrointestinal tract?

Meissner's Plexus Signup and view all the answers

What type of activity is primarily regulated by the enteric nervous system?

Motor and secretory activity of the GI tract Signup and view all the answers

What effect does the activation of parasympathetic preganglionic fibers have on the enteric nervous system (ENS)?

Increases GIT motor and secretory activity Signup and view all the answers

Which of the following neurotransmitters is associated with cholinergic transmission in the autonomic nervous system?

Acetylcholine Signup and view all the answers

Which statement about autonomic activities is true?

Some autonomic activities can be voluntarily controlled under certain conditions. Signup and view all the answers

Which component of the autonomic nervous system is specifically associated with the gastrointestinal region?

Enteric nervous system Signup and view all the answers

What is the primary effect of sympathetic activation on heart rate?

Increases heart rate Signup and view all the answers

What is one of the main types of fibers that inhibit the activity of enteric neurons?

Sympathetic postganglionic fibers Signup and view all the answers

Which of the following is true regarding the dual innervation of visceral organs?

Sympathetic and parasympathetic fibers often have opposite effects Signup and view all the answers

In the context of defecation, what does a rectal pressure of 18mmHg indicate?

Increased urge to defecate but can still control it Signup and view all the answers

Which neural structure is primarily involved in pupil dilation via sympathetic activation?

Oculomotor nerve Signup and view all the answers

What is an example of a sympathetic and parasympathetic interaction in digestive motility?

Sympathetic decreases motility; parasympathetic increases motility Signup and view all the answers

Where are neurotransmitters released in autonomic nervous system pathways?

At the autonomic ganglion and the effector organ level Signup and view all the answers

What happens to heart rate if the vagus nerve innervating the sinoatrial (SA) node is cut?

Heart rate increases (tachycardia) Signup and view all the answers

Which neurotransmitter is responsible for adrenergic transmission?

Norepinephrine Signup and view all the answers

What is the role of enteric neurons in relation to the digestive tract?

They act independently of sympathetic and parasympathetic control Signup and view all the answers

Study Notes

Overview of the Autonomic Nervous System

Comprises the autonomic (visceral) nervous system, which oversees involuntary functions.
Divided into the sympathetic nervous system, parasympathetic nervous system, and enteric nervous system.

Sensory and Motor Impulses

Afferent Nerves: Transmit sensory impulses from receptors to the central nervous system (CNS).
Efferent Nerves: Carry motor impulses from the CNS to effectors, such as smooth muscle in the gut.

Enteric Nervous System

Regulates gastrointestinal (GI) tract activities through two main plexuses:
- Myenteric Plexus (Auerbach’s Plexus): Located in the muscular layer; controls motor activities like peristalsis.
- Meissner’s Plexus: Found in the submucosal layer; manages secretory functions of the GI tract.

Autonomic Activities

Many autonomic functions are involuntary but can be partially voluntary (e.g., breathing, urination, and defecation).
Reflex actions are triggered when certain thresholds are exceeded (e.g., bladder stretching).

Dual Innervation

Most visceral organs receive both sympathetic and parasympathetic innervation, often resulting in opposing effects.
Examples:
- Sympathetic stimulation increases heart rate; parasympathetic decreases it.
- Sympathetic decreases intestinal motility; parasympathetic increases it.

Role of Neurotransmitters

Acetylcholine (ACh): Main neurotransmitter in cholinergic transmission affecting both somatic and autonomic pathways.
Norepinephrine (NEP): Key neurotransmitter in adrenergic transmission, primarily affecting sympathetic responses.

Biochemical Transmission

Neurotransmitter agents mediate motor impulse transmission through the release at synapses.
Mechanisms include:
- Exocytosis into the synaptic cleft.
- Binding to receptors on target effectors, resulting in physiological responses.
- Subsequent deactivation of the neurotransmitter post-response through enzymatic processes.

Sympathetic and Parasympathetic Drugs

Parasympatholytic Drugs:
- Block cholinergic effects; examples include Atropine leading to effects like tachycardia.
Sympathomimetic Drugs:
- Enhance sympathetic effects; examples include adrenaline for pupil dilation and bronchodilation.
Sympatholytic Drugs:
- Inhibit sympathetic activity, resulting in a decrease of NEP synthesis and release.

Clinical Applications

Asthma Treatment: Usage of beta-2 agonists, like Salbutamol, to achieve bronchodilation during bronchoconstriction episodes.

Studying That Suits You

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

Description

Test your knowledge on the autonomic nervous system and its functions. This quiz covers the components of the autonomic system, including visceral afferents and effectors that influence saliva production. Ideal for students studying human physiology or anatomy.