ANS Flashcards
ANS CONTROL CENTERS
spinal cord brain stem hypothalamus (also operates via visceral reflexes)
hypothalamus controls
water balance,feeding control, heat control
brain stem controls
urinary bladder, pneumotaxic center, cardiac accleration and vasoconstriction, cardiac slowing, respiratory center
sympathetic fibers vs parasympathetic fibers
sympathetic pre fibers are short post are long. opposite for parasympathetic
sympathetic efferent fibers originate
in spinal cord T1 to L2
preganglionic transmission options
- )Synapse directly with postganglionic fibers
- ) Follow preganglionic pathway to one of two peripheral ganglia where they synapse with postganglionic fibers
- ) Pass through the sympathetic chains then through the splanchnic nerves to the two adrenal medullae
Sympathetic fibers & the skeletal nerves
Some postganglionic fibers that originate in the sympathetic chains pass back into the spinal cord at all levels of the cord
They then extend to all parts of the body via the skeletal nerves
percentage of sympathetic fibers in skeletal nerves
8%. they control pili erector, sweat glands some blood vessels
cranial nerve 3
ciliary ganglion and ciliary muscles of eye
cranial nerve 7
pupillary sphincter, sphenopalatine ganglion, lacrimal glands, nasal glands
cranial nerve 5
submandibular ganglion, submandibular gland
cranial nerve 9
otic ganglion, parotid gland
cranial nerve 10
heart, stomach, pylorus, colon, small intestine, ileocecal valve, anal sphincter, detrusor, trigone,
sacral 1-4
only parasympathetic fibers from vertebrae. mostly come from 2 and 3
celiac ganglion organs
pylorus, adrenal medulla, kidney, ureter, intestine ileocecal valve, anal sphincter
hypogastric plexus
bladder, trigone, detrusor
organs that have no peripheral ganglion
eye, heart, bronchi
amount of molecules in transmitter vesicle
200-10000
4 different actions of alpha component
1.)pen specific ion channel through post synaptic membrane (long lasting).
2.)Activation of cyclic adenosine monophosphate (cAMP) of cyclic guanosine monophosphate (cGMP)( Can activate a variety of metabolic activities)
3.) Activation of one or more intracellular enzymes
4.) Activation of gene transcription
(Create changes in metabolic machinery or cellular structure)
all ANS preganglionic fibers release
ACH
most post ganglionic fiber of parasympathetic fiber release
ACH
most post ganglionic fiber of sympathetic fiber release
noreepinephrine (except sweat glands pili erector and some blood vessels which release ACH)