Block 1 Exam Flashcards
(361 cards)
What is the difference between the motor neurons in the somatic NS vs the ANS?
-Somatic innervates skeletal muscles; voluntary
-ANS: innervates smooth muscle, cardiac muscle, and glands; involuntary
What neurotransmitter is always released by the preganglionic neurons in the ANS?
ACh
What neurotransmitter is released from postganglionic neurons in the sympathetic and parasympathetic NS? What is the exception to this?
-Sympathetic: norepineprhine
-Parasympathetic: ACh
-Sweat glands have sympathetic input but only use ACh as a neurotransmitter
What is another name for the sympathetic NS?
-“Fight or flight”
-Thoracolumbar system
What is another name for the parasympathetic NS?
-“Rest and digest”
-Craniosacral system
What is the role of the parasympathetic division?
-SLUD
-Salivation
-Lachrymation
-Urination
-Defecation
-BP, HR, and RR are low
-GI tract activity is high
-Pupils are constricted and lenses are accommodated for close vision
What is the role of the sympathetic division?
-Mobilizes the body during activity
-Promotes adjustments during exercise or when threatened
-Blood flow is shunted to skeletal muscles and heart
-Bronchioles dilated
-Liver releases glucose
What are the functional aspects of the parasympathetic NS?
-Constricts pupils
-Stimulates salivation
-Inhibits heart
-Constricts bronchi
-Stimulates GI tract
-Stimulates gallbladder
-Contracts bladder
-Relaxes rectum
What are the functional aspects of the sympathetic NS?
-Dilates pupils
-Inhibits salivation
-Relaxes bronchi
-Accelerates heart
-Inhibits digestive activity
-Stimulates glucose release by liver
-Secretion of epinephrine and norepinephrine from kidney
-Relaxes bladder
-Contracts rectum
What receptors are there in the sympathetic NS?
-⍺-1
-⍺-2
-β-1
-β-2
What receptors are there in the parasympathetic NS?
Muscarinic
What types of receptors do ACh bind to?
-Nictonic receptors
-Muscarinic receptors
Where are nicotinic receptors found?
-Motor end plates of skeletal muscles
-All ganglionic neurons (sympathetic and parasympathetic)
-Hormone-producing cells of the adrenal medulla
-Effect of ACh at nicotnic receptors is always stimulatory
Where are the muscarinic receptors found?
-Found on all effector cells stimulated by postganglionic cholinergic fibers
-The effect of ACh at muscarinic receptors can either be excitatory or inhibitory
What are the two types of adrenergic receptors?
-Alpha
-Beta
What is sympathetic tone?
-Sympathetic NS controls BP even at rest
-Keeps blood vessels in a continual state of partial constriction
-Sympathetic fibers fire more rapidly to constrict blood vessels and cause BP to rise
What is parasympathetic tone?
-Parasympathetic NS dominates the heart and smooth muscle of GI tract and urinary tract organs
-Slows the HR
-Dictates normal activity levels of the digestive and urinary tracts
What are unique roles of the sympathetic NS?
-The adrenal medulla, sweat glands, and blood vessels only receive sympathetic fibers
-Controls thermoregulatory responses to heat
-Release of renin from the kidneys
-Metabolic effects
Where are β-1 receptors located that are stimulated by the sympathetic NS? What are its effects?
-Heart (increase HR)
-Salivary glands (increases)
-Adipose tissue (lipolysis)
-Kidney (renin secretion)
Where are ⍺-1 receptors located that are stimulated by the sympathetic NS? What are its effects?
-Skin (constricts)
-Smooth muscle sphincters (contracts)
-Pupils (dilation-mydriasis)
Where are β-2 receptors located that are stimulated by the sympathetic NS? What are its effects?
-Bronchioles (dilates)
-Blood vessels to skeletal muscle (dilates)
-Smooth muscle walls (relaxes)
-Bladder wall muscle (relaxes)
-Liver (gluconeogenesis, glycogenolysis)
Where are ⍺-2 receptors located that are stimulated by the sympathetic NS? What are its effects?
Smooth muscle walls (relaxes)
What are cholinergic agonists? What is another name for them?
-Mimic the effects of acetylcholine
-Also referred to as “parasympathomimetics”
What are the two types of cholinergic agonists?
-Direct: mimic the activity of ACh at the cholinergic receptors
-Indirect: inhibit the actions of acetylcholinesterase