Pharmacology of the Autonomic Nervous System Flashcards
What are the two branches of the ANS? What is the major role of each?
- sympathetic: energy output; “fight or flight”
- parasympathetic: energy conservation; “rest and digest”
How many times does a fiber from the somatic nervous system synapse once it leaves the CNS? How about a fiber from the autonomic nervous system?
- somatic: no synpase!
- autonomic: one synapse, creating a pre and post-ganglion
The sympathetic branch of the ANS involves the _________ regions; the parasympathetic branch involves the __________ regions.
- sympathetic: thoracicolumbar
- parasympathetic: craniosacral
T or F: the CNS uses ACh to communicate to ALL branches of the PNS.
- true!
- ACh is used to send signals to the somatic branches (no synapse), as well as to the autonomic branches (one synapse, once it reaches the synapse, the communication method can change)
What organ of the autonomic nervous system does NOT have a synapse?
- the adrenal medulla
- all other fibers of the ANS do have a synapse
What are the two types of cholinergic receptors?
- muscarinic and nicotinic
What role does Ca2+ play in signaling?
- Ca2+ influx results in the release of ACh via exocytosis
Acetylcholine Esterase (ACh-E)
- breaks down ACh to cut off the signal transduction
- opposite function of choline acetyltransferase
Skeletal muscles are innervated by the ________ NS and have ________ receptors.
- somatic nervous system; nicotinic receptors
Choline Acetyltransferase
- makes ACh from choline and acetyl CoA
- opposite function of ACh esterase
Nicotinic receptors are _________, while muscarinic receptors are ___________.
- nicotinic = ligand-activated cation channels
- muscarinic = G-protein coupled receptors
There are five types of muscarinic receptors (M1 –> M5), which are stimulatory and which are inhibitory?
- stimulatory: M1, M3, and M5
- inhibitory: M2 and M4
What are the effects of parasympathetic innervation?
- S.L.U.D.G.E. - B.B.B.
- salivation, lacrimation, urination, defecation, gastro-emesis, bronchorrhea, bronchospasm, bradycardia
In general terms, the parasympathetic NS is associated with ________ receptors and the sympathetic NS is associated with ________ receptors; both have _________ receptors at their ganglionic synapse.
- parasympathetic: muscarinic
- sympathetic: adrenergic
- ganglionic synapse: nicotinic
What are the four types of adrenergic receptors? What is the function of each?
- alpha-1: smooth muscle contraction
- alpha-2: inhibits release of norepinephrine (negative feedback)
- beta-1: cardiac muscle contraction
- beta-2: smooth muscle relaxation
Given that we use Beta Blockers to treat HTN, what is a common side effect of these drugs? What can we do in these situations?
- beta-blockers will block beta-1 and beta-2 adrenergic receptors; blocking beta-1 will result in cardiac relaxation, while blocking beta-2 will result in smooth muscle contraction –> therefore, a common side effect is difficulty breathing
- to avoid this, we can give the patient a beta-1 specific blocker
Which effectors use muscarinic receptors?
- all effectors of the parasympathetic NS
- sweat glands of the sympathetic NS
Which effetors use adrenergic receptors?
- all effectors of the sympathetic NS, EXCEPT for the sweat glands
