Types of smooth muscle
vasculature
bladder
reproductive tracts
GI tract
respiratory tract
skin
eye
Types of Muscarinic receptors
M1, M2, M3
QIQ
Location and function of M1
multiple functions in Nerve endings
Location and function of M2
decelerates the heart rate
Location and function of M3
contracts smooth muscle including bladder wall and bronchi
relaxes sphincters (increases GI motility)
increases secretions in glands
vasodilates
contracts the circular and ciliary muscle for near vision accommodation
Location and function of alpha1
constricts smooth muscle and sphincters
Location and function of alpha2
decreases transmitter release at nerve endings
Location and function of beta1
increases heart rate and contractibility in cardiac muscle
Increases renin secretion in kidney
, Location and function of beta2
relaxes smooth muscle including bronchi and bladder wall,
increases glucose availability in liver and skeletal muscle
Location and function of beta3
increases lipolysis in adipose
Tone at rest
most organs are controlled by PNS but cardiac ventricle and vascular smooth muscle
are controlled by SNS
Different effects on receptors for epinephrine and norepinephrine
Epinephrine can act on B2 receptors along with alpha and beta1
But norepinephrine cannot act on B2
SLUD-BBAM
Salivation
Lacrimation
Urination
Diarrhea
Bradycardia
Bronchoconstriction
Abdominal Cramps
Miosis
Direct Acting Muscarinic Agonists effect
Induce PNS like control (SLUD-BBAM)
Direct Acting Muscarinic Agonists
Bethanechol- ileus and urinary rentention
Methacholine- challenge test for asthma
Pilocarpine- dry mouth, glaucoma, sjogren's syndrome
Antimuscarinic effects
They inhibit Parasympathetic action so activity of drug will mimic sympathetic effects
(opposite of SLUD-BBAM)
Antimuscarninics (muscarinic antagonists)