7. Actions of Ach
Characteristics M1
(neuronal)
M2
(cardiac)
M3
(glandular)
Location &
Function
⢠Ganglia â
impulse
transmission
⢠SA node
-Decreased rate
of impulse
generation
⢠AV node â
decreased
conduction
velocity
⢠Atrium,
ventricle-
decreased
contractility
⢠Exocrine
glands-
secretion
⢠Visceral
smooth Muscle
â contraction
8. Actions of Ach
Characteristics M1
(neuronal)
M2
(cardiac)
M3
(glandular)
Location &
Function
⢠Ganglia â
impulse
transmission
⢠SA node
-Decreased rate
of impulse
generation
⢠AV node â
decreased
conduction
velocity
⢠Atrium,
ventricle-
decreased
contractility
⢠Exocrine
glands-
secretion
⢠Visceral
smooth Muscle
â contraction
9. Actions of Ach
Characteristics M1
(neuronal)
M2
(cardiac)
M3
(glandular)
Location &
Function
⢠Ganglia â
impulse
transmission
⢠SA node
-Decreased rate
of impulse
generation
⢠AV node â
decreased
conduction
velocity
⢠Atrium,
ventricle-
decreased
contractility
⢠Exocrine
glands-
secretion
⢠Visceral
smooth Muscle
â contraction
10. Actions of Ach
Characteristics M1
(neuronal)
M2
(cardiac)
M3
(glandular)
Location &
Function
⢠Ganglia â
impulse
transmission
⢠SA node
-Decreased rate
of impulse
generation
⢠AV node â
decreased
conduction
velocity
⢠Atrium,
ventricle-
decreased
contractility
⢠Exocrine
glands (salivary,
sweat)
-secretion
⢠Visceral
smooth Muscle
(bronchus,
bladder, GIT) â
contraction
11. Actions of Ach
Characteristics NM
(muscle type)
NN
(neuronal type)
Location &
Function
Skeletal
neuromuscular
junction (NMJ) â
contraction
⢠Autonomic
gangliaâ impulse
transmission
12. Actions of ACh on eye
Muscarinic:
ďEye:
-Circular muscle of iris (M3)- contraction-
miosis
-Ciliary muscle (M3) â contraction- eyeâs
focus is accomodated for near vision â
spasm of accomodation
-Better drainage of aqueous humor â reduced
intraocular pressure
-Lacrimal glands (M3) - lacrimation
16. 2. Indirectly acting (Anticholinesterases)
A. Reversible :
Physostigmine, neostigmine,
pyridostigmine, edrophonium
B. Irreversible:
Organophosphates: Parathion, Malathion
17. Mechanism of action of
Anticholinesterases
ďInhibit acetylcholinesterase (AChE) enzyme
ďAch -----------ď Choline + acetate
AChE
ďAccumulation of Ach ď Action
Neostigmine
___
_
18. Therapeutic uses
ďOphthalmic use :
i) Glaucoma
ii)To counteract the effects of mydriatics
iii) To break adhesions between the iris and
lens or iris and cornea
ďMyasthenia gravis : neostigmine
ďBelladona (Atropine) poisoning :
Physostigmine â specific antidote
28. ďGenitourinary tract :
Relaxation of ureter and urinary bladder â
urinary retention
ďGlands :
Decreases sweat, salivary, tracheobronchial
and lacrimal secretion
ďBody temperature :
Rise in body temperature
âAtropine feverâ
29. Uses of atropineUses of atropine
ďPreanaesthetic medication: to decrease
secretion
ďOraganophosphorous poisoning
30. Therapeutic usesTherapeutic uses
ďMotion sickness : Scopolamine
ďParkinsonâs disease :benzhexol,
benztropine etc.
ďBronchial asthma : ipratropium and
tiotropium bromide
ďPreanaesthetic medication :
glycopyrrolate ,
ďAs mydriatic during fundoscopy and
testing of refractive error â Tropicamide,
cyclopentolate
31. Side effects of atropine :
ďDry mouth
ďBlurred vision and photophobia
ďUrinary retention
ďConstipation
ďDry, hot skin
ďPrecipitation of glaucoma
ďDecreased sweating