U4 lecture 33 Flashcards
what does the vagus nerve do (X)
mixed cranial nerve; carries 80% of parasympathetic outflow to heart, airways, liver, gallbladder, stomach, small intestine and part of large intestine
what happens in the cranial portion in the PNS
80% of PSNS info carried by vagus (X)
what happens in the sacral portion in the PNS
preganglionic neurons in sacral region exit via pelvic nerves
where are nicotinic receptors found and what do they do
found on sympathetic and parasympathetic cell bodies and dendrites of postganglionic neurons (within the ganglion)- can only generate excitatory post synaptic potentials
where are the muscarinic receptors found and what do they do
found on membrane of target tissues innervated by parasympathetic postganglionic axons- can generate both EPSP and inhibitory post synaptic potentials (IPSP)
what is the general function and goal of the PSNS
rest and digest
goal- promote digestion of food and the absorption of nutrients
what does SLUD stand for
Salivation, Lacrimation, Urination, Defecation
what are the specific responses to PSNS
- increased digestive enzyme/hormone secretion
- increased smooth muscle activity of the GI tract
- constriction of pupils for near vision
- decreased heart rate, contractility, blood pressure
- contraction of muscular wall of bladder and intestine; promotes urination/ defecation
- increased secretion of lacrimal glands
what does a transient loss of consciousness result from
an insufficient supply of oxygen to the brain
what causes an insufficient cerebral perfusion from hypertension
failure of ANS to maintain blood pressure
how can syncope be avoided
by laying down in supine position elevating feet contracting leg and arm muscles to bring more blood back to the heart and increase circulation of blood to the brain
