Sympathetic vs Parasympathetic Overview

Dual innervation

almost all visceral organs are served by both the sympathetic and parasympathetic division, but they cause opposite effects

What are exceptions to dual innervation (3)

Sweat glands, arrector pili, adrenal medulla → only have sympathetic innervation

What are the two subdivisions of the ANS

Sympathetic and parasympathetic

Parasympathetic

rest and digest system → maintenance

promotes maintenance activities (homeostasis) and conserve body energy

A person relaxing, reading, after a meal is an example of what division

what happens to heart blood respiratory and gastrointestinal tract activity

what happens to pupils / eyes

Parasympathetic → blood pressure heart rate and respiratory rates all all low,

gastrointestinal tract activity is high

pupils are constricted aned lenses are accommodated for close vision (relaxed = close vision no need to be alert for danger)

Sympathetic division

fight or flight system → mobilizes body during activity, exercise, and stress/danger

What happens to bloodflow, bronchioles (lungs), liver, and pupils during sympathetic

Blood flow to skeletal muscles and heart

bronchioles dilate (expand)

liver release glucose for fuel

pupils dilate → see environment

Origin of sympathetic fibers

thoracolumbar region of spinal cordOr

orgin of parasympathetic fibers

brain and sacral spinal cord (craniosacral)

Length of fibers for sympathetic and why

short preganglionic and long post ganglionic

because ganglion is close to CNS spinal cord (short trip before ganglion, long trip after)

Length of fibers for parasympathetic and why

long preganglionic and short post ganglionic because ganglion is in or near effector organs (so long trip before ganglion and short trip after ganglion)