Exam 5 Flashcards
(121 cards)
What is another name for the autonomic system?
Visceral nervous system
Autonomic nervous system
efferent innervation of tissues other than skeletal muscle, some examples are cardiac and smooth muscle, adipocytes, and glands
What is the difference between somatic and autonomic nervous systems?
somatic controls voluntary while autonomic control involuntary
What is the difference between somatic neuron and visceral neurons?
somatic neuron is single, long axon, excitatory while visceral neurons are pre and post synaptic neurons, excitatory or inhibitory
Ganglion
postsynaptic neuron that has its cell body in the ganglion that will continue onto the target tissue
Preganglionic neuron
presynaptic neuron sends message to ganglion
What are the two divisions of the ANS?
sympathetic (fight or flight) and parasympathetic (rest and digest)
Dual innervation
every organ receives input from both sympathetic and parasympathetic divisions
Sympathetic division
preganglionic neuron - originate entirely of the CNS (thoracic to lumbar), postganglionic neuron - trunks span from cervical to sacral
What is the 3 categories of sympathetic postganglionic neurons?
sympathetic chain, collateral ganglia, and adrenal
Sympathetic chain
majority of the postsynaptic fibers originate in this region, directly adjacent to the spinal cord on both sides (symmetrical), insert into organs/glands of head, heart, lungs
Collateral ganglia
preganglionic neurons come through both ventral roots, regulating functions of digestive system and reproductive system, located on ventral surface
What are the types of the collateral ganglia?
celiac, superior mesenteric, inferior mesenteric
Adrenal medulla
post ganglionic neurons are endocrine tissue not neurons, inner layer, contains chromaffin cells
Adrenal cortex
true endocrine tissue, outermost layer
Chromaffin cells
endocrine cells that are regulated by the nervous system, releases secretions (epinephrine and norepinephrine) into the bloodstream
Where do the preganglionic cell bodies originate in the parasympathetic division?
cranial nerves - oculomotor, facial, glossopharyngeal, vagus, spinal cord - S2, S3, S4
What is the autonomic function of the cranial nerves?
oculomotor - control tear ducts (auto-lacrimal cells), facial - produce saliva, glossopharyngeal - regulate saliva production, vagus - “the wonderer”
Parasympathetic innervation
preganglionic axons pass to peripheral ganglia within target organs, preganglionic neurons are long and myelinated while postganglionic neurons are short and typically unmyelinated
What is the physiology of “fight or flight”?
increased heart rate, sweating, constrict blood flow in GI and urinary system, dilate blood flow around skeletal muscle, increased respiration rate, dilation of airways
How is the sympathetic division able to be systemic?
able to activate lots of neurons because the Adrenal medulla is activated since lot of epinephrine is released into the bloodstream to activate all those regions
What is the physiology of “rest and relax”?
decreased heart rate, increased GI activity, dilate blood blow around GI, decrease respiration rate, always constricted
How is the parasympathetic division able to be systemic?
it is like a reset button, does not rely on the endocrine system, not organized for mass discharge
Cholinergic neurons
acetylcholine is released, all preganglionic neurons in both divisions are this, postganglionic neurons of parasympathetic division are this too