Autonomic Nervous System Flashcards
(35 cards)
Portion of the peripheral nervous system that functions without conscious effort (involuntary)
Autonomic Nervous System
What does the ANS do
it mainly regulates visceral activities and maintains homeostasis
What does the ANS consist of
Efferent Viceral nerve fibers and associated ganglia
Autonomic Function are
reflex actions controlled from centers in the Hypothalamus, Brain Stem and spinal cord
Small clusters of neurons (including cell bodies) outside the CNS
Ganglia
What do the Ganglia do in the ANS
they integrate impulses before sending them out into the body; this allows some independence in function
The nerve fibers carry an impulse to the ganglion from the CNS
Preganglionic Fibers
Nerve fibers that carry an impulse from the ganglion to effector
Postganglionic Fibers
Most visceral organs are mainly made active by one division of the ANS
Visceral Organ Control
What are the two division of the ANS
Sympathetic and Parasympathetic; they often act antagonistically to each other.
What does the Sympathetic division do; what does the stress stand for
It prepares the body for stressful and emergency conditions; “stress or scared”
What activates “Fight or Flight”
Activated by rage or fear
What are the effects of the Sympathetic Division
~Increased heart rate ~Increased Blood Pressure ~Decreased G.I. movement and secretions ~Decreased bowel and urine flow ~Dilation of airways and pupils (extra O2 and vision) ~Blood flow is shifted from skin,mucosa, and abdominal viscera to the heart, brain, and skeletal muscle ~Increased sweating ~Orgasm/ Ejaculation
Sympathetic Nerve Fibers are located on
the nerves from the thoracic and lumbar regions
Preganglionic fibers for the Sympathetic division are
short
Postganglionic fibers for the Sympathetic division are
Long
Ganglia of the sympathetic division are located alongside the vertebral column
Paravertebral Ganglia
Neurotrasmitters of the Sympathetic Division
Acetylcholine- secreted by preganglionic nerves
Norepinephrine- secreted by postganglionic nerves
What are the two receptors of the Sympathetic Division
Nicotonic Cholinergic Receptors; Adrenergic receptors
Where can nicotinic cholinergic receptors be found and what does it react to
at ganglion; acetylcholine but also Nicotine
Where can Adrenergic receptors be found and what does it react to
at effector, reacts to norepinephrine
“peaceful” diviosion of ANS, most active under ordinary conditions
Parasympathetic division
What does the parasympathetic division do
it allows for energy conservation and restoration
What are the effects of the Parasympathetic Division
~Decreases Heart rate ~Decreases Blood pressure ~Increased G.I. movements and secretions ~Empties the bladder and rectum ~Constriction of airways and pupils ~Erection of penis/clitoris
