C14 9-11 Flashcards
Splanchnic nerve?
formed by symp preganglionic nerves that pass thru the sympathetic trunk without terminating in it.
What do splanchnic nerves contribute to?
The abdominal aortic plexus.
It contains the celiac, superior mesenteric and inferior mesenteric ganglia (named for the arteries the are closest to.)
Greater splanchnic nerve ganglion/innervates?
Adrenal medulla (directly), intestines, spleen, stomach, liver, gallbladder.
Connects to cell bodies in CELIAC ganglion and Sup. Mesenteric ganglion.
Lesser splanchnic nerve ganglion/innervates?
small intestine, ganglion unknown.
Lumbar splanchnic nerve ganglion/innervates?
Large intestine, rectum.
Inferior mesenteric ganglion
Sacral splanchnic nerve ganglion/innervates?
Genitalia, urinary bladder. Chain ganglia?
Sympathetic/trunk ganglia pathway to the head?
T1-T4 ascend to superior cervical ganglion in sym trunk and synapse.
Dilate Eye, inhibit nasal and salivary glands, innervated tarsal muscle that lifts eyelid.
Sympathetic/trunk ganglia pathway to the thorax?
T1-T6 Axons synapse in the cervical trunk and form cervical nerves. Innervate heart via cardiac plexus, thyroid, mostly skin.
OR
synapse with nearest trunk ganglia, then run through plexuses.
Innervate the Heart, aorta, lungs, esophagus.
What are the sympathetic splanchnic nerves coming off T5 and down?
Greater and lesser (thoracic), lumbar and sacral.
What does the abdominal aortic plexus include?
Celiac, superior and inferior mesenteric ganglion.
Cholerginic fiber?
Nerve fibers that release acetylcholine. (all ANS preganglionic axons, all parasympathetic postganglionic axons)
Adrenergic fiber?
Nerve fibers that release norepinephrine (most sympathetic postganglionic axons)
Cholerginic receptor types?
muscarinic, nicotinic
Adrenergic receptor types?
alpha (1-2), beta (1-2-3)
Where are nicotinic receptors found? What is the effect of Ach binding?
Neuromuscular junctions,
All postganglionic neurons - sym and para, Hormone producing cells of the adrenal medulla.
Always stimulatory, opens ion channels, depolarizes.
Where are muscarinic receptors found? What is the effect of Ach binding?
All effector cells stimulated by postganglionic cholinergic fibers (all parasympathetic target organs!!)
(also on a couple symp targets - eccrine sweat glands)
Inhibitory or stimulatory (binding to cardiac muscle slows heart, binding to gastro increases m
Where are adrenergic receptors found? What is the effect of NE binding?
Any organs that respond to NE.
Inhibitory or stimulatory depending on subclass that dominates in organ.
(i.e. NE binding to b1 of cardiac increases heart activity. NE binding to b2 in bronchiole causes it to relax.)
ionotropic?
channel-linked, open ion channels directly, cholinergic/nicotinic receptors
metabotropic?
G-linked protein, open ion channels indirectly. (Changes metabolism)
Includes: second messengers/cAMP, cholerginic/muscarinic receptors, adrenergic receptors (alpha/beta)
Ca+ influx is most common
B1
Heart - increase hr, strength of contraction
B2
Lungs - bronchodilation
B3
Adipose - release lipids/lipolysis
Alpha 1
Blood vessels serving skin - vasoconstriction
Alpha 2
Membrane of adregenic axon terminals - Inhibits NE release from adregenic terminals
- Describe the clinical importance of drugs that mimic or inhibit adrenergic or cholinergic effects.
Knowing the locations of cholerginic and adreginic receptor subtypes allows clinicians to prescribe specific drugs to stimulate or inhibit selected target organs. Better living through chemistry.
Agonist?
Substance that binds to and activates a receptor (mimicks) i.e phenylephrine mimics adregenic at alpha 1 and constricts blood vessels in nasal mucosa.
Antagonist?
Binds or blocks a receptor preventing a natural neuro or hormone from exerting its effect. i.e. atropine blocks muscarinic Ach receptors - pupils dilate.
Is cocaine a agonist or antagonist?
Antagonist - blocks reuptake of NE
