Chapter 16: The Nervous System - Autonomic Nervous System

These flashcards cover key concepts, definitions, and comparisons related to the Autonomic Nervous System as presented in Chapter 16.

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

To control involuntary actions of effectors such as glands, cardiac muscle, and smooth muscle.

What type of reflexes does the ANS involve?

Visceral reflexes which are unconscious, automatic, and stereotyped responses to stimuli.

What are the two main divisions of the ANS?

The sympathetic division and the parasympathetic division.

What is the sympathetic division responsible for?

'Fight-or-flight' responses that increase heart rate and blood glucose, and reduce blood flow to the skin and gastrointestinal tract.

What does the parasympathetic division promote?

'Rest and digest' responses that decrease heart rate and stimulate digestion.

What is meant by 'Autonomic Tone'?

The balance between activity of the sympathetic and parasympathetic nervous systems.

How many nerve fibers are involved in the efferent pathways of the ANS?

Two nerve fibers are involved: a preganglionic fiber and a postganglionic fiber.

What characterizes the sympathetic division's preganglionic fibers?

They are short with their neurosomas located in the lateral horns of the spinal cord.

Where are the terminal ganglia of the parasympathetic division located?

Near or within the target organs.

What is the Enteric Nervous System?

The nervous system of the digestive tract that innervates smooth muscle and glands.

What is one disorder associated with the ANS and its symptoms?

Horner syndrome, which presents as unilateral pupillary constriction, sagging eyelid, and flushing of skin.

What are typical symptoms of Raynaud disease?

Paleness, cyanosis, and pain in digits when cold or stressed due to excessive vasoconstriction.