ANS Overview Flashcards
Sympathetic nervous system response
fight or flight
parasympathetic nervous system response
rest and digest
Which nervous system contains peripheral ganglions (2 neuron path)?
sympathetic and parasympathetic (autonomic nervous system)
What is the primary neurotransmitter of all preganglionic neurons?
Acetylcholine
What is the neurotransmitter in all parasympathetic nervous system post ganglionic neurons?
Acetylcholine
What is the transmitter in most sympathetic postganglionic neurons?
norepinephrine
What target tissues are the exception for sympathetic postganglionic neurons?
Sweat glands, renal vasculature, adrenal medulla
What is the transmitter in the postganglionic neuron for sweat glands?
Acetylcholine
What is the transmitter in the postganglionic neuron for renal vascular smooth muscle?
Dopamine
What is the transmitter in the postganglionic neuron for the adrenal medulla?
Epinephrine and norepinephrine
What is the primary neurotransmitter for the somatic nervous system?
Acetylcholine
What type of receptor is located at the synapse between preganglionic and postganglionic neurons? (both sympathetic and parasympathetic)
nicotinic receptors
What type of receptor is activated on the target organ by parasympathetic neurons? What is the neurotransmitter?
muscarinic receptor; activated by acetylcholine
What neurotransmitter is released at the synapse between preganglionic neurons and postganglionic neurons? (both sympathetic and parasympathetic)
Acetylcholine
What type of receptor is activated on the target organ by most sympathetic neurons? What is the neurotransmitter?
adrenergic receptors (alpha and beta); activated by norepinephrine
What do post-ganglionic neurons involved with stress-related excretion release?
norepinephrine
What do post-ganglionic neurons involved with thermoregulation release?
Acetylcholine
Where do adrenal pre-ganglionic neurons synapse?
directly on the adrenal gland
What is the neurotransmitter released by preganglionic adrenal neurons? What is the receptor?
acetylcholine; nicotinic receptors.
What neurotransmitter do adrenal glands release into systemic circulation?
epinephrine
What neurotransmitter acts on the renal vascular smooth muscle? What receptor?
Dopamine; D1 dopamine receptor.
What is the neuron type for the parasympathetic nervous system?
Cholinergic
What is the neuron type for the sympathetic nervous system?
Adrenergic
What is the endogenous neurotransmitter for cholinergic receptors?
Acetylcholine
What are the exogenous neurotransmitters for the cholinergic receptors?
Nicotine and Muscarine
What are the endogenous neurotransmitters for the adrenergic receptors?
epinephrine (Epi) and norepinephrine (NE)
What are drugs that mimic neurotransmitters referred to as? What this their effect on receptors?
receptor agonists; they activate receptors
What are drugs that block neurotransmitters referred to as? What is their effect?
receptor antagonists; they block the endogenous neurotransmitters from activating receptors.
What are the two types of cholinoceptors? What are their subtypes? Which part of the ANS do they primarily affect?
Nicotinic: Nm, Nn
Muscarinic: M1, M2, M3
Parasympathetic
What are the two types of adrenoceptors? What are their subtypes? Which part of the ANS do they primarily affect?
Alpha: A1, A2
Beta: B1, B2, B3
Sympathetic
Where are the nicotinic receptors located?
ganglia, skeletal muscle, and the neuronal CNS
What type of receptor is the nicotinic receptor?
5 subunit ionotropic sodium ion channel
What is the primary neurotransmitter for the nicotinic receptor? exogenous neurotransmitter?
acetylcholine; nicotine (selective)
What type of receptor is the muscarinic receptor?
7 transmembrane domain G-protein coupled receptor
Which cholinergic receptors are associated with the Gq pathway ?
M1, M3, and M5
Which cholinergic receptors are associated with the Gi pathway?
M2 and M4
Describe the pathway for M1, M3, and M5 cholinergic receptors
Signal via Gq pathway; IP3 mobilizes Calcium from intercellular stores; DAG activates protein kinase C.
Describe the pathway for M2 and M4 cholinergic receptors
Signal via Gi pathway; inhibits adenylyl cyclase
Describe the pathway for a1 adrenergic receptors
Signal via Gq pathway; calcium mobilized from intercellular stores; DAG activates protein kinase C
Where are a1 adrenergic receptors found?
vascular smooth muscle; genitourinary smooth muscle; intestinal smooth muscle; heart; liver
What is the effect of activated a1 adrenergic receptor?
mediates vasoconstriction
Describe the pathway for a2 adrenergic receptors
Signals via Gi pathway; inhibits adenylyl cyclase; reduced CAMP-dependent protein kinase activity; activates certain K+ channels.
Where are a2 adrenergic receptors found?
found pre-synaptically; function as autoreceptors to inhibit sympathetic output
What is the function of a2 adrenergic receptors?
Autoreceptors to inhibit sympathetic output; results in decreased transmitter release
Describe the pathway for B1, B2, and B3 adrenergic receptors
Signal through Gs pathway; activates adenylyl cyclase; increased cAMP leading to protein kinase activation; results in phosphorylation of ion channels and other proteins.
M2&4 vs B1 receptor; what is the interaction?
Gi (M2&4) vs Gs (B1) the M receptors counteract B1 receptors, reducing cAMP-dependent protein kinase activity
Which neurotransmitters are involved in sympathetic mechanisms? What are the receptors called?
norepinephrine and epinephrine; adrenergic receptors
Which neurotransmitters are involved in parasympathetic mechanisms; what are the receptors called?
acetylcholine; cholinergic receptors
Which adrenergic receptor mediates the rate of contraction in the heart? What is the response?
B1>B2; rate of contraction increases
Which adrenergic receptor mediates the force of contraction in the heart? what is the response?
B1>B2; force of contraction increases
Which cholinergic receptor mediates the rate of contraction in the heart? What is the response?
M2; rate of contraction decreases
Which cholinergic receptor mediates the force of contraction in the heart? What is the response?
M2; force of contraction decreases
Which adrenergic receptor mediates the contraction in most arteries? What is the response?
a1; vasoconstriction
Which adrenergic receptor mediates the contraction in most veins? What is the response?
a1&2; vasoconstriction
Which adrenergic receptor mediates the contraction of vasculature in most skeletal muscle? What is the response?
B2; vasodilation
What cholinergic receptor mediates contraction in endothelium? What is the response?
M3; Releases EDRF (strong vasodilator)
predominant tone (symp vs parasymp) of arterioles
sympathetic
predominant tone (symp vs parasymp) of veins
sympathetic
Predominant tone (symp vs parasymp) of sweat glands
sympathetic
Predominant tone (symp vs parasymp) of heart
parasympathetic
Predominant tone (symp vs parasymp) of eye (iris)
parasympathetic
Predominant tone (symp vs parasymp) of eye (ciliary body)
parasympathetic
Predominant tone (symp vs parasymp) of GI tract
parasympathetic
Predominant tone (symp vs parasymp) of bladder
parasympathetic
Predominant tone (symp vs parasymp) of salivary gland
parasympathetic
Which adrenergic receptor mediates the bronchiolar smooth muscle in the lung? What is the response?
B2; bronchodilation
Which cholinergic receptor mediates the bronchiolar smooth muscle in the lung? What is the response?
M2&3; bronchoconstriction
What adrenergic receptor mediates the bladder wall? What is the response?
B3; relaxation
What adrenergic receptor mediates the ureter? What is the response?
a1; contraction
Which adrenergic receptor mediates the sphincter? What is the response?
a1; contraction
Which adrenergic receptor mediates the pregnant uterus? What is the response?
B2; relaxation
a1; contraction
Which adrenergic receptor mediates the penis/ vas deferens? What is the response?
a1; ejaculation
Which cholinergic receptor mediates the bladder wall? What is the response?
M3; contraction
Which cholinergic receptor mediates the ureter? What is the response?
M3; relaxation
Which cholinergic receptor mediates the sphincter? what is the response?
M3; relaxation
Which cholinergic receptor mediates the pregnant uterus? What is the response?
M3; variable response
Which cholinergic receptor mediates the penis/ vas deferens?
M3; erection
Which adrenergic and cholinergic receptors mediate the salivary glands? What is the response?
a1; increases secretion
M3; increases secretion
Which adrenergic and cholinergic receptors mediate the smooth muscle walls in the GI tract?
a2 and B2; relaxation
M3; contraction
Which adrenergic and cholinergic receptors mediate the smooth muscle sphincters in the GI tract?
a1; contraction
M3; relaxation
Which adrenergic and cholinergic receptors mediate secretion in the GI tract?
a2; inhibit secretion
M3; increase secretion
Which part of the ANS is the skin controlled by?
The sympathetic nervous system only
Which adrenergic receptor mediates the hair follicles and smooth muscle in the skin? Response?
a1; contraction and piloerection
Which receptor mediates thermoregulation in the skin? Response?
M3; increase secretion
Which receptor mediates stress in the skin? What is the response?
a1; increase secretion
Which receptors regulate glycogenolysis and gluconeogenesis in the liver?
a1;B2 adrenergic
Which receptors regulate the metabolic function of fat cells? What is the response?
a1; B1,2,3; lipolysis
Which receptors regulate the metabolic function of the kidney? What is the response?
B1; increase renin secretion
Which receptors regulate the metabolic function of the pancreas? What is the response?
a2; decrease insulin release
What receptor regulates the radial muscle in the eye? What is the response?
a1; contraction
What receptor regulates the circular muscle in the iris? what is the response?
M3; contraction
What receptor regulates the ciliary muscle in the eye? What is the response? Symp/parasymp?
Sympathetic: B2; relaxation
Parasympathetic; contraction; M3
What receptor regulates the ciliary epithelium in the eye? What is the response?
b2; increase secretion of aqueous humor
What receptor regulates the lacrimal glands? What is the response? Sympathetic vs parasympathetic?
Sympathetic: a1; mucus and enzymes
Parasymp: M3; tears (watery)
Which part of the nervous system controls the arteries and veins?
Sympathetic only; a1 and B2; constriction and dilation
Which muscle and receptor control pupillary constriction?
Circular muscle; constricted by parasympathetic nerves and M3
Which muscle and receptor control pupillary dilation?
Radial muscle; sympathetic nerves and a1
Which receptors and muscles are targeted in treatment of glaucoma?
M3 agonist- ciliary muscle
a2 agonist- ciliary body
B antagonist- ciliary epithelium
