Autonomic Nervous System Flashcards
The autonomic nervous system consists of ______
visceral neurons aka pre and post ganglionic neurons
True or false: the effects of the ANS is only excitatory
false: it is both excitatory and inhibitory
only somatic is only excitatory
Sympathetic Organization: pregangionic neurons originates here and the post ganglion neurons are innervated by
pre: CNS (T1 to L2)
post: sympathetic chain, collateral, adrenal
Where are the majority of the sympathetic post ganglionic fibers?
sympathetic chain ganglia
What are the target organs of the sympathetic chain ganglia
head, heart, lungs
Where are the collateral ganglia found
in the abdominal cavity
What are the target organs of the collateral ganglia?
stomach, duodenum, pancreas, liver, kidney, colon
Where is the sympathetic chain ganglion?
on both sides of the spinal cord
“fight or flight” reinforced by
epinephrine
preganglionic cell bodies originate from ______ in the parasympathetic nervous system
cranial nerves and sacral region of the spinal cord
(parasympathetic) preganglionic axons pass to peripheral ganglia …
within or very close to target organs
parasympathetic preganglionic cells are _____ than the post ganglionic
longer
sympathetic preganglionic cells are ____ than post ganglionic
shorter
True or false: the parasympathetic nervous system is organized for mass discharge
false; not connected enough
Antagonistic effects of sympathetic and parasympathetic
sympathetic and parasympathetic fibers innervate the same cells; the actions counteract each other
Complementary effects of sympathetic and parasympathetic
sympathetic and parasympathetic stimulation produces similar effects
Cooperative effects of sympathetic and parasympathetic
sympathetic and parasympathetic stimulation produce different effects that work together to produce desired effect
Organs without dual innervation
regulation achieved by increasing or decreasing firing rate of postganglionic neurons; ex.organs innervated solely by sympathetics: adrenal medulla
in both divisions what neurotransmitter is released by the preganglionic neuron
ACh
The cholinergic signals are terminated by…
enzymatic degradation by acetylcholinesterase; or diffusion
Cholinergic refers to
ACh
The sympathetic post ganglionic neurons release
epinephrine and norepinephrine
The parasympathetic post ganglionic neurons release
ACh
Adrenergic signals are terminated by…
active transport, diffusion, enzymatic degradation (MAO- monoamine oxidase)
nicotinic receptors are found
on the post ganglionic cells
nicotinic agonists and antagonists
agonists: acetylcholine, nicotine
anatagonist: TEA, curare
What type of receptors are found on the target organs of the parasympathetic system
muscarinic
What are the agonists and antagonists of the muscarinic receptors
agonists: acetylcholine, muscarine
antagonist: atropine
receptors found on target organs (sympathetic)
adreneric receptors
What do Gq coupled receptors do?
makes IP3 (SR Ca2+ channel)-> calcium rise-> causes contraction of smooth muscle (phosphorylation of the MLCK)
What do Gi coupled receptors do?
decreases cAMP -> contraction
What do Gs coupled receptors do?
increase cAMP levels -> no contraction
What does cAMP do
it inhibits contraction
What are the effects of alpha 1 receptors
Gq= smooth muscle constriction
What are the effects of alpha 2 receptors
Gi= smooth muscle contraction; secretion inhibition
What are the effects of the beta adrenergic receptors?
Gs= relaxation
What are the effects of the B1 receptors
increased heart rate and contractility
What are the effects of the B2 receptors
smooth muscle relaxation
What are the effects of the B3 receptors
enhance lipolysis (improving energy supply)
norepinephrine stimulates
alpha1, alpha 2, and beta 1
epinephrine stimulates
all alpha and beta receptors
decreased GI activity is from
alpha 2 receptors
Sweating is different than the other sympathetic responses because
it uses muscarinic receptor (still sympathetic but it uses cholinergic signaling)
beta 2 receptors cause vasodilation where
heart, lungs, muscles- places you need blood during a fight or flight response
Would a MOA inhibitor cause a parasympathetic or a sympathetic response
sympathetic
Where are the autonomic control centers
in the spinal cord, brain stem, hypothalamus
Hypothalamus
water balance, temp reg, hunger
Pons
secondary respiratory center, cardiovascular center
Medulla
respiratory center, cardiovascular center
What are sympathetic reflexes
cardioacceleratory, vasomotor reflex
What are parasympathetic reflexes
swallowing reflex, gastric and intestinal reflex, coughing reflex
If TEA or curare was given to a patient would it affect their pre or post ganglionic neurons
it would affect their pre ganglionic neurons (would affect nicotinic receptors)
