A&P 1 Ch15 EXAM GUIDE

Autonomic(visceral/involuntary) Nervous System

motor neurons that innervate involuntary tissues(effector organs) such as smooth and cardiac muscle and glands via varicosities

Cell bodies of the Autonomic nervous system are located in the…….

Central nervous system(axons are located in the peripheral nervous sytem)

The Autonomic Nervous System effect is

stimulatory or inhibitory

Parasympathetic Division of the ANS

aka: craniosacral division(loc. @ cranial & sacral nerves), Autonomic Ganglia close to effector organs, Neuron chains consist of long preganglionic & short postganglionic fibers, Cranial outflow to oculomotor, facial, glossopharyngeal, and vagus nerves

Sympathetic Division of the ANS

aka:thoracolumbar division(loc. @ thoracic & lumbar nerves), short preganglionic & long postganglionic fibers (synapses between fibers), mostly contained in Sympathetic Chain Ganglia.

Sympathetic Preganglionic fibers enter the Sympathetic Chain through the….

White Communicating Ramus (rami)postganglionic fiber immediately

Postganglionic fibers can exit the chain ganglion, and return to the spinal nerve via the…..

Gray Communicating Ramus

in some situations, preganglionic neurons exit the sympathetic trunk and travel as ________ ________ to ______ _______ where they synapse with postganglionic neurons

splanchnic nerves; collateral ganglia

Dual Innervation

most organs of the body are controlled by nerve innervation from the two ANS divisions

Parasympathetic division function

rest & digest neurons, reduced body energy expenditure, digestion, elimination of waste

sympathetic division function

fight, flight, fear neurons. Mobilizes the body when we are threatened or excited.Typically inhibits or reduces the processes controlled by
the Parasympathetic division

Dynamic antagonism

when both the sympathetic & parasympathetic systems work together.

Autonomic tone results from….

balanced simultaneous activity of the sympathetic and parasympathetic
divisions on most organs, maintains necessary muscular tone in organs

ANS Neurotransmitters: Acetylcholine

a short-lived, localized control over its effector organs due to Acetylcholinesterase activity, secreted by cholinergic fibers.

Nicotinic Cholinergic Receptors

also bind to ACH & nicotine; always cause excitatory responses in cells

Muscarinic Cholinergic Receptors

also bind to muscarine; are found in cardiac, smooth, and gland cells; Can cause an excitatory response in some cells & an inhibitory response in other cells

ANS Neurotransmitters: Norepinephrine (NE) & Epinephrine (E)

long lasting, diffuse control over effector organs. Circulate in blood after release by adrenal medulla to produce widespread affects

adrenergic fibers

sympathetic postganglionic fibers that release NE & E. Bind to NE.

Alpha (α1 and α2) – usually have excitatory effects
– Beta (β1, β2 and β3) – usually have inhibitory effects

Hypothalamus

ANS control center, receives input from limbic system to ediate reactions, Controls heart, blood pressure, body temperature, water, endocrine, sex drive, rage, pleasure, thirst and hunger all through thr brain stem & reticular formation.

cerebral cortex

Sends input to the Limbic system, Memories can cause our heart to race, Thoughts of food can cause stomach to “growl

spinal chord

Regulates many autonomic reflexes such as urination, defecation, erection and ejaculation. Cortical control can override urination and defecation when necessary