Autonomic Nervous System Overview

These flashcards cover key concepts related to the autonomic and somatic nervous systems, their functions, and responses.

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

Sympathetic nervous system and parasympathetic nervous system.

What neurotransmitter is associated with the sympathetic nervous system's preganglionic fibers?

Acetylcholine (ACh) is released by preganglionic fibers, while norepinephrine (or adrenaline) is associated with postganglionic fibers.

What is dual innervation in the autonomic nervous system?

It refers to the phenomenon where certain organs receive nerve fibers from both sympathetic and parasympathetic nervous systems.

What is the function of the parasympathetic nervous system?

It promotes 'rest and digest' activities, helping to conserve energy and restore the body.

What is the main role of the sympathetic nervous system?

It prepares the body for 'fight or flight' responses, increasing heart rate, blood flow, and alertness.

What type of receptors does acetylcholine bind to in the autonomic nervous system?

Cholinergic receptors, which can be excitatory or inhibitory.

How do sympathetic and parasympathetic systems affect heart rate?

Sympathetic stimulation increases heart rate, while parasympathetic stimulation decreases it.

What are sympathomimetics?

Medications that enhance sympathetic nervous system activity.

What are parasympathomimetics?

Medications that enhance parasympathetic nervous system activity.

What is the significance of the hypothalamus in autonomic responses?

It is the control center for emotions and initiates the fight or flight response.

What do excitatory postsynaptic potentials (EPSP) and inhibitory postsynaptic potentials (IPSP) indicate?

EPSPs indicate a higher likelihood of action potential firing, while IPSPs indicate a lower likelihood.

What is vasomotor tone?

It refers to the degree of constriction or dilation of blood vessels, influenced by both sympathetic and parasympathetic control.

What is the role of the spinal cord in autonomic functions?

It transmits signals between the brain and body, facilitating autonomic responses and reflexes.

What is the relationship between emotions and the autonomic nervous system?

Emotions can significantly influence autonomic responses, affecting heart rate and other bodily functions.

What is the function of adrenergic receptors in the sympathetic nervous system?

They mediate the effects of norepinephrine, with alpha receptors typically being excitatory and beta receptors often being inhibitory.

How does the body respond to stress or danger under the sympathetic nervous system?

It triggers increased heart rate, blood pressure, and energy mobilization to prepare for quick action.

What are the differences in preganglionic fiber lengths between the sympathetic and parasympathetic systems?

Sympathetic preganglionic fibers are short, while parasympathetic fibers are long.

How do medications like beta-blockers affect the body?

They inhibit sympathetic activity, slowing the heart rate and reducing blood pressure.

Describe the effect of cooperative and antagonistic responses in the autonomic nervous system.

Cooperative responses involve both systems working together, while antagonistic refers to one system opposing the other.

What physiological responses are triggered by the parasympathetic nervous system?

Decreased heart rate, increased digestive activity, and energy conservation.

What types of fibers are involved in the communication of the autonomic nervous system?

Cholinergic fibers release acetylcholine, while adrenergic fibers release norepinephrine.

What are the general functions of the somatic nervous system?

It controls voluntary movements by innervating skeletal muscles.