Lec 12 - Autonomic NS Flashcards
what does autonomic mean
-not under voluntary ctrl but at a subconscious lvl
what are the two branches of the ANS
-sympathetic and parasympathetic
what is dual innervation
-the fact that both divisions of the ANS innervate most effector organ
what is the primary fxn of the ANS
regulate organs to maintain homeostasis
which ANS division is active during “rest and digest” and “fight or flight”
-rest: parasympathetic
-fight: sympathetic
what two neurons run from the CNS to effector organs
-preganglionic neuron
-postganglionic neuron
what are the autonomic ganglia
-cluster of synapses b/w the preganglionic and postganglionic neurons
-called intrinsic (intermediary) neurons
what are the effector organs of the ANS
-cardiac muscle, smooth muscle, glands, adipose tissue
where do preganglionic neurons of the SNS stem from
-thoracolumbar spinal cord (in the lateral horn which consists of grey matter)
what do short preganglionic and long postganglionic of the sympathetic NS connect to, how are they linked, what are the exceptions to this anatomy
-short go to the sympathetic chain
-long go from the chain to effector organs
-ganglia are linked tgt in a sympathetic chain
-exceptions: adrenal medulla, collateral ganglia outside the chain
where do preganglionic neurons enter and exit the sympathetic chain, which neurons do they communicate w
-exits via ventral root of spinal cord
-enter spinal nerve
-axons leave spinal nerve as white ramus and enter sympathetic ganglia
-communicate w ganglia in postganglionic neurons
where do postganglionic neurons exit the sympathetic chain, through what nerve do they travel to effector organs
-leave ganglia as grey ramus and re enter in the spinal nerve
-spinal nerve
what are the hormones of the adrenal medulla
-epinephrine, norepinephrine, sm amt of dopamine
what are the collateral ganglia
-the third type of anatomical arrangement of sympathetic fibres
-includes: celiac ganglia, superior mesenteric ganglia, inferior mesenteric ganglia
where are the celiac ganglia, superior mesenteric ganglia, inferior mesenteric ganglia
-celiac: innervate stomach, liver, spleen
-sup: innervate SI, upper LI, kidneys
-inf: innervate LI, bladder, repro organs
what is the diff b/w the thoracolumbar and craniosacral division of the ANS
-thoraco = sympathetic, spends energy
-cranio = parasympathetic, produces energy
where do the preganglionic neurons of the para NS originate from
-brainstem and sacral spinal cord
what do the long preganglionic and short postganglionic neurons of the para NS do
-long pre: go to ganglia near effector organ, communicate w postganglionic neuron in ganglia
-short post: go from ganglia to effector organs
what is the oculomotor nerve
cranial nerve III that innervates smooth muscle of the eye, makes lens globe shape and improves near vision
what is the facial nerve
cranial nerve VII in the face to innervate salivary glands to increase secretions
what is the glossopharyngeal nerve
cranial nerve IX that innervates smooth muscle of throat (incl middle ear and eust tube)
what is the vagus nerve
cranial nerve X that innervates heart, lungs, stomach, SI, liver
do the sacral nerves of the para NS join the spinal nerve, what do they innervate
-no
-innervate colon, bladder, repro organs to increase activity
what do the afferent and efferent fibres of the autonomic nerves do
-aff: send info from visceral receptors to CNS, provide feedback ab internal enviro for maintaining homeostasis
-eff: form autonomic NS
