Pharm Flashcards
(27 cards)
What are components of Enteric Nervous system, their location, and Fx?
Myenteric / Auerbach’s plexus- between longitudinal and Circular muscle. Fx: Controls motility of SM
Submucosal/Meissner’s plexus- deep to muscularis mucosa. Controls secretion and flow rate.
Lcoation of PANS & SANS central roots of origin
Preganglionic fibers originate
PANS: Cranial nerve nuclei 3, 7, 9, 10 in sacral segments (S2-S4)
SANS: Thoracicolumbar
ACh is primary transmitter in what parts of ANS?
- All ANS ganglia (where Pre and Postsynaptic meet)
- PANS: Postganglionic neurons & effector tissues
- SANS sweat glands
- SANS Adrenal medulla
Not ANS: somatic; skeletal muscle
Major Fx of α1 receptor
↑vascular SM contraction ↑pupillary dilator (radial)muscle contraction = Mydriasis ↑intestinal and bladder contraction Apocrine sweat (stress) glands Pilomotor muscles Ejaculation
Major Fx of α2 receptor
↓sympathetic outflow ↓insulin release (beta cells of pancreatic islets) ↓lipolysis ↑PLT aggregation ↑GI secretion
Some presynaptic terminals, pancreatic islets
(beta cells), platelets, ciliary epithelium, smooth
muscle, CNS neurons.
Major function of Beta1 receptor?
↑HR (SA node, ectopic pacemaker)
↑contractility
↑renin release
↑lipolysis
Myocardium, JG cells, some
presynaptic terminals, adipocytes, CNS neurons.
Major Fx of Beta2 receptors?
Vasodilation Bronchodilation ↑HR ↑Contractility ↑Lipolysis ↑Insulin ↓uterine tone Ciliary muscle relaxation ↑Aqueous humor production
Describe receptors for ACh
Nicotinic: Na/K ligand gated
Nn- autonomic ganglia
Nm- NMJ
Muscarinic- Gprotein coupled, 2nd messenger action
M1,2,3,4,5
What part of SANS has cholinergic innervation?
Sweat glands
Adrenal medulla
Fx of M1 receptors?
CNS & ENS
Fx of M2 receptors?
↓HR
↓atrial contractility & nodal activity
Fx of M3 receptors
↑exocrine gland secretion(lacrimal, gastric)
↑GI peristalsis
↑bladder contraction
↑bronchoconstriction
↑pupillary spinchter contraction = Miosis
Ciliary muscle contraction = accommodation (see closer; lens thickens)
SM, exocrine glands, vascular
endothelium, CNS neurons.
Fx of D1 & D2 receptors?
D1: relaxes Renal SM vasculature
D2: modulates transmitter release, mostly Brain
Fx of H2 receptor?
↑stomach acid release (parietal cells)
Fx of H1 receptors?
↑nasal and bronchial mucus production
↑bronchiole contraction
Pruiritis and pain
Fx of V1 & V2 receptors?
V1: vascular SM contraction
V2: ↑H2O permeability and reabsorbtion in CTs of kidney
“V2 found in 2 kidneys”
What are Gproteins for ANS receptors?
"QISS and QIQ till you're SIQ of SQS" α1,α2,ß1, ß2 M1, M2,M3 D1,D2,H1 H2, V1, V2
Gq 2nd messenger pathway? Which ANS receptors apply>
Gq→ Phospholipase C, leads to Lipids→PIP2→IP3 and DAG →↑[Ca] and Protein Kinase C →SM contraction
PKC P’s proteins
“HAVe 1 MandM2”
Gs pathway.
ANS receptors for Gs and Gi
Gs→Adenylyl cyclase→ cAMP→PKA→↑[Ca]in (heart), and PKA inhibits Myosin light chain kinase (SM)
ß1, ß2,D1,H2,V2
Gi inhibits Adenylyl cyclase
M2,α2,D2
“MAD 2’s”
MOA of PDE3 inhibitor(Milrinone)?
Stops PDE3, which breaks up cAMP.
Therefore, ↑cAMP activity
Milrinone allows stimulation of cardiac function independently of β-adrenergic receptors which appear to be down-regulated in those with heart failure.
List drugs that effect Cholinergic terminal directly and how (3 drugs)
Hemicholinium- blocks uptake of choline
Vesamicol- Prevents storage of ACh
Botulinum- prevents transmitter release by cleaving v-SNARE protein synaptobrevin
Which receptors modulate at the Noradrenergic nerve terminal?
M2
Angiotensin II
Alpha-2: autoregulation by NE (negative feedback)
MOA of Reserpine?
irreversibly blocks VMAT, which transports free intracellular norepinephrine, serotonin, and dopamine in the presynaptic nerve terminal into presynaptic vesicles for subsequent release into the synaptic cleft (“exocytosis”).
MOA of Metyrosine?
Prevent Tyrosine conversion to DOPA, thus, preventing NE formation down same pathway
