Autonomic Nervous System Overview

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What effect does the mass discharge of the sympathetic nervous system NOT have on the body?

Increased muscle strength

Increased arterial pressure

Decreased rates of cellular metabolism (correct)

Increased blood flow to active muscles

Which of the following is a characteristic of the sympathetic stress response?

Reduction in mental activity

Increased glycolysis in the liver and muscle (correct)

Increased blood flow to the gastrointestinal tract

Decreased blood glucose concentration

Which emotional state is specifically mentioned as activating the sympathetic nervous system?

Sadness

Happiness

Rage (correct)

Calmness

What reaction is commonly referred to as the fight-or-flight response?

Sympathetic alarm reaction Signup and view all the answers

How does the sympathetic nervous system alter blood flow during a stress response?

Increases blood flow to active muscles and decreases to non-essential organs Signup and view all the answers

What is the primary hormone secreted by the adrenal medullae?

Epinephrine Signup and view all the answers

What is the average proportion of norepinephrine secreted compared to epinephrine?

20 percent Signup and view all the answers

Which effect is primarily caused by norepinephrine?

Constriction of most blood vessels Signup and view all the answers

How does epinephrine differ from norepinephrine in relation to cardiac stimulation?

Epinephrine has a greater effect on cardiac stimulation. Signup and view all the answers

Which statement accurately describes the duration of effects caused by epinephrine and norepinephrine?

The effects last between 2 to 4 minutes. Signup and view all the answers

What is a significant metabolic effect of epinephrine compared to norepinephrine?

Epinephrine increases metabolic rate significantly. Signup and view all the answers

Which of the following is NOT an effect of norepinephrine?

Weak constriction of blood vessels in muscles Signup and view all the answers

What is the effect of epinephrine on arterial pressure compared to norepinephrine?

Norepinephrine raises arterial pressure more than epinephrine. Signup and view all the answers

What are the two main divisions of the human nervous system?

Central and Peripheral Nervous System Signup and view all the answers

Which types of cells support and protect neurons in the nervous system?

Glial cells Signup and view all the answers

Which statement best describes the role of neurons in the nervous system?

Neurons can rapidly change the ionic gradient across their membranes in response to stimuli. Signup and view all the answers

What is the primary function of the peripheral nervous system?

Conducting impulses to and from the central nervous system. Signup and view all the answers

What distinguishes small-molecule rapidly acting transmitters from neuropeptides?

Small-molecule transmitters typically elicit acute responses while neuropeptides usually cause prolonged actions. Signup and view all the answers

Which type of receptor is responsible for detecting changes in temperature?

Thermoreceptors Signup and view all the answers

What do we call the network formed by the interconnections of neurons?

Neural network Signup and view all the answers

Which of the following is not a function associated with neuropeptides?

Acute transmission of sensory signals to the brain Signup and view all the answers

Which of the following is NOT a characteristic of neurons?

Participate in neural nutrition. Signup and view all the answers

What is the main role of glial cells?

Support and protect neurons. Signup and view all the answers

What is the primary function of nociceptors?

Detect pain from physical or chemical damage Signup and view all the answers

Which type of receptor is NOT classified as one of the five basic sensory receptors?

Electrochemical receptors Signup and view all the answers

Which of the following best describes the role of nerve cells in the nervous system?

They process information and generate responses. Signup and view all the answers

What role do mechanoreceptors primarily serve?

Sense mechanical compression or stretching Signup and view all the answers

The chemoreceptors can detect all of the following except:

Temperature of the skin Signup and view all the answers

How do neuropeptides influence neuronal activity?

By inducing prolonged changes in synaptic function Signup and view all the answers

What is the primary function of the Pacinian corpuscle?

To detect mechanical pressure and vibration Signup and view all the answers

What happens to the central nerve fiber of the Pacinian corpuscle when compression occurs?

It experiences deformation that leads to receptor potential Signup and view all the answers

What ions diffuse into the central nerve fiber during the production of receptor potential?

Sodium ions Signup and view all the answers

What initiates the action potentials in the central nerve fiber of the Pacinian corpuscle?

Opening of ion channels leading to sufficient depolarization Signup and view all the answers

What structural characteristic of the Pacinian corpuscle enhances its sensitivity to pressure?

Concentric capsule layers surrounding the nerve fiber Signup and view all the answers

Where is the first node of Ranvier located in relation to the Pacinian corpuscle?

Inside the capsule of the corpuscle Signup and view all the answers

Which of the following bodily functions is NOT primarily controlled by the autonomic nervous system?

Voluntary muscle movement Signup and view all the answers

What is the role of the autonomic nervous system in relation to arterial pressure?

It helps to regulate arterial pressure automatically Signup and view all the answers

Study Notes

Autonomic Nervous System (ANS)

The autonomic nervous system regulates visceral body functions including arterial pressure, gastrointestinal motility, and body temperature.
It is divided into the sympathetic and parasympathetic nervous systems.

General Organization of the ANS

Consists of two main divisions: sympathetic and parasympathetic.
Sympathetic system mediates stress responses while the parasympathetic system promotes rest and digest activities.

Physiological Anatomy of Sympathetic and Parasympathetic Systems

Sympathetic system: prepares the body for "fight or flight," increases heart rate, dilates pupils, and inhibits gastrointestinal function.
Parasympathetic system: promotes "rest and digest," slows heart rate, constricts pupils, and enhances digestive processes.

Cholinergic and Adrenergic Fibers

Cholinergic fibers release acetylcholine as their neurotransmitter.
Adrenergic fibers release norepinephrine or epinephrine, involved in sympathetic responses.

Mechanism of Transmitter Secretion and Removal

Transmitter secretion occurs at postganglionic endings via synaptic vesicles.
Removal can occur through reuptake, enzymatic degradation, or diffusion away from the synapse.

Acetylcholine Receptors

Two principal types:
- Nicotinic receptors: found at the neuromuscular junction and autonomic ganglia.
- Muscarinic receptors: found in various tissues, particularly in the parasympathetic system.

Major Adrenergic Receptors

Two main types:
- Alpha receptors: primarily mediate vasoconstriction and increased peripheral resistance.
- Beta receptors: promote vasodilation, increased heart rate, and metabolic effects.

Excitatory and Inhibitory Actions

Sympathetic stimulation: generally excitatory, increasing heart rate, dilating bronchi, and inhibiting digestion.
Parasympathetic stimulation: generally inhibitory, decreasing heart rate and promoting digestion.

Function of the Adrenal Medullae

Secretes epinephrine (80%) and norepinephrine (20%) into the bloodstream during sympathetic activation.
Increases metabolic activity, enhances cardiac output, and prolongs sympathetic effects.

Sympathetic and Parasympathetic Tone

Sympathetic tone dominates during stress, preparing the body for emergency responses.
Parasympathetic tone is more active during restful states, facilitating recovery and conservation of energy.

Reaction Example

Laura’s reaction to run and confront a threat exemplifies the sympathetic alarm reaction, leading to heightened physical activity through increased heart rate and energy mobilization.

Studying That Suits You

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

Description

This quiz covers key concepts related to the autonomic nervous system (ANS), including its organization and the anatomy of sympathetic and parasympathetic divisions. It also explores neurotransmission mechanisms and the types of receptors involved in cholinergic and adrenergic signaling. Test your understanding of these essential physiological processes!