The Autonomic Nervous System

Flashcards about the Autonomic Nervous System.

What is the function of the Autonomic Nervous System (ANS)?

It consists of neurons that innervates smooth and cardiac muscle and glands, making adjustments to support body activities via subconscious control.

What are the axons of the ANS ?

Preganglionic (first) neuron has a lightly myelinated axon

Ganglionic (second) neuron extends to an effector organ

What are the two divisions of the motor division?

Autonomic nervous system and Somatic nervous system

Name three ways the ANS differs from the SNS.

Effectors, Efferent pathways, Target organ responses

What are the effectors of the Somatic Nervous System (SNS)?

Skeletal muscles

What are the effectors of the Autonomic Nervous System (ANS)?

Cardiac muscle, smooth muscle, and glands

Describe the efferent pathway of the Somatic Nervous System.

Heavily myelinated axons extend from the CNS to the effector.

Describe the efferent pathway of the Autonomic Nervous System.

A two-neuron chain: preganglionic neuron (lightly myelinated axon) and ganglionic neuron (extends to effector organ).

What neurotransmitter is released by all somatic motor neurons?

Acetylcholine (ACh)

What neurotransmitters are released by postganglionic fibers in the ANS?

Norepinephrine or ACh

What two divisions comprise the ANS?

Sympathetic and parasympathetic

Which division of the ANS mobilizes the body during extreme situations?

Sympathetic division

The sympathetic division is also known as?

Fight or Flight

Which division of the ANS performs maintenance activities and conserves body energy?

Parasympathetic division

The parasympathetic division is also known as?

Rest and Digest

What are the "D" activities associated with the parasympathetic division?

Digestion, defecation, and diuresis

What are the "E" activities associated with the sympathetic division?

Exercise, excitement, emergency, and embarrassment

Where do sympathetic fibers originate?

Thoracolumbar region of the spinal cord

Where do parasympathetic fibers originate?

Brain and sacral spinal cord

Which has short preganglionic and long postganglionic fibers, sympathetic or parasympathetic?

Sympathetic

Which has long preganglionic and short postganglionic fibers, sympathetic or parasympathetic?

Parasympathetic

What are the two major neurotransmitters of the ANS?

Acetylcholine (ACh) and norepinephrine (NE)

What are cholinergic fibers?

ACh-releasing fibers

What are adrenergic fibers?

Sympathetic postganglionic axons that release NE

What are the two types of cholinergic receptors?

Nicotinic and muscarinic

Where are nicotinic receptors found?

Motor end plates, all ganglionic neurons, and hormone-producing cells of the adrenal medulla

Where do muscarinic receptors occur?

All effetor cells stimulated by postganglionic cholinergic fibers.

What are the two types of adrenergic receptors?

Alpha and beta

What does atropine do?

Blocks parasympathetic effects

What does Neostigmine do?

Inhibits acetylcholinesterase