Acetylcholine -
Acetylcholine is an organic chemical that functions in the brain and body of many types of animals as a neurotransmitter—a chemical message released by nerve cells to send signals to other cells, such as neurons, muscle cells and gland cells.
Neurohumoral transmission in CNS-
The term neurohumoral transmission designates the transfer of a nerve impulse from a presynaptic to a postsynaptic neuron by means of a humoral agent e.g. a biogenic amine, an amino acid or a peptide.
Acetylcholine (ACh):- is an organic chemical that functions in the brain
and body of many types of animals, including humans, as a
neurotransmitter—a chemical released by nerve cells to send signals
to other cells.Its name is derived from its chemical structure: it is an
ester of acetic acid and choline. Parts in the body that use or are
affected by acetylcholine are referred to as cholinergic.
Acetylcholine is the neurotransmitter used at the neuromuscular
junction—in other words, it is the chemical that motor neurons of
the nervous system release in order to activate muscles.
.Acetylcholine is also used as a neurotransmitter in the autonomic
nervous system, both as an internal transmitter for the sympathetic
nervous system and as the final product released by the
parasympathetic nervous system.
Acetylcholine -
Acetylcholine is an organic chemical that functions in the brain and body of many types of animals as a neurotransmitter—a chemical message released by nerve cells to send signals to other cells, such as neurons, muscle cells and gland cells.
Neurohumoral transmission in CNS-
The term neurohumoral transmission designates the transfer of a nerve impulse from a presynaptic to a postsynaptic neuron by means of a humoral agent e.g. a biogenic amine, an amino acid or a peptide.
Acetylcholine (ACh):- is an organic chemical that functions in the brain
and body of many types of animals, including humans, as a
neurotransmitter—a chemical released by nerve cells to send signals
to other cells.Its name is derived from its chemical structure: it is an
ester of acetic acid and choline. Parts in the body that use or are
affected by acetylcholine are referred to as cholinergic.
Acetylcholine is the neurotransmitter used at the neuromuscular
junction—in other words, it is the chemical that motor neurons of
the nervous system release in order to activate muscles.
.Acetylcholine is also used as a neurotransmitter in the autonomic
nervous system, both as an internal transmitter for the sympathetic
nervous system and as the final product released by the
parasympathetic nervous system.
depression ,symptoms, mechanism of depression ,classification of antidepressants , tri cyclic anti depressants and its pharmacological actions ,acute poisoning and treatment
Introduction to Physiological and pathological role of serotonin
Autocoids, Classification, synthesis ,Serotonergic receptors, Physiological actions, Pathophysiological role
Presented by
K.Firdous banu
Department of Pharmacology
cholinergic receptors definetion and classifcation to 1-nicotinic and 2-muscarinic ...and their subtybes ..... then the sites and the mechanism ... and last the drugs effect
pharmacology,clinical pharmacology,clinical,injections,pharmacological,what is pharmacology,lethal injection drugs,pharmacology definition,Plus review of anatomy of the ANS
depression ,symptoms, mechanism of depression ,classification of antidepressants , tri cyclic anti depressants and its pharmacological actions ,acute poisoning and treatment
Introduction to Physiological and pathological role of serotonin
Autocoids, Classification, synthesis ,Serotonergic receptors, Physiological actions, Pathophysiological role
Presented by
K.Firdous banu
Department of Pharmacology
cholinergic receptors definetion and classifcation to 1-nicotinic and 2-muscarinic ...and their subtybes ..... then the sites and the mechanism ... and last the drugs effect
pharmacology,clinical pharmacology,clinical,injections,pharmacological,what is pharmacology,lethal injection drugs,pharmacology definition,Plus review of anatomy of the ANS
clinical pharmacology,clinical,injections,pharmacological,what is pharmacology,lethal injection drugs,pharmacology definition,Plus review of anatomy of the ANS
The parasympathetic division typically acts in opposition to the sympathetic autonomic nervous system through negative feedback control.
This action is a complementary response, causing a balance of sympathetic and parasympathetic responses.
Overall, the parasympathetic outflow results in the conservation and restoration of energy, reduction in heart rate and blood pressure, facilitation of digestion and absorption of nutrients, and excretion of waste products.
These are drugs that produce actions similar to that of Acetylcholine hence known as parasympathomimetics.
They act either by directly interacting with cholinergic receptors or by increasing the availability of Acetylcholine at these sites.
Neurohumoral Transmission of Acetylcholine.pptxShraddhaRaut43
This presentation will provide you an insight into the Neurohumoral Transmission of Acetylcholine in Autonomic Nervous System. Acetylcholine is a chemical messenger and principle neurotransmitter of Parasympathetic Nervous system. It will help you to cover this topic from syllabus and from exam point of view. Check out the ppt to boost your knowledge on this topic as it gives you a detailed knowledge of acetylcholine transmission.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
2. 1. Introduction
Acetylcholine is a chief neurotransmitter of
parasympathetic nervous system which is a part of
autonomic nervous system.
Neurotransmitters-
• Chemical messengers
• Transmit a message (impulse) from one nerve to another,
finally to target cell.
• Target cell can be nerve cell/ muscle cell/ gland cell
Nervous system can be broadly classified into two parts:
CNS(central nervous system) and PNS(peripheral nervous
system)
3. PNS- Connects CNS to various
organs
Efferent(Motor) neurons-
Carry impulses away from CNS
Afferent (sensory) neurons-
Carry impulses towards the CNS
Parasympathetic- Aka as Digest
or rest system
Sympathetic- Aka Fight or flight
system
Ach
4. Chemically Ach is an ester of acetic acid and choline.
First time Ach was found or discovered in the vagus nerve
hence previously it was known as “vagustoff”
It was the first neurotransmitter to be identified.
Two receptors are identified on which Ach acts- Nicotinic
and Mucarinic
6. Biosynthesis
Choline (an amino acid) enters presynaptic neuron along
with Na+ ion through a symporter choline
transporter(CHT).
Mitochondria inside the neuron synthesizes and releases
acetyl coenzyme A (Acetyl coA).
Acetyl CoA combines with choline in the presence of
enzyme ChAT (choline acetyl transferase).
ChAT makes an ester bond between Acetyl CoA and
Choline thus forming Aetylcholine
7. Storage
Synthesized Ach is stored in a vesicle.
VAT (vesicle associated transporter), an antiporter transports Ach into
the vesicle. As Ach goes in, the H+ ion already present in the vesicle
moves outside into the neuron.
Each vesicle contains about 1000 to 50,000 molecules of Ach.
Vesicles are provided with certain proteins- VAMPs (Vesicle associated
membrane proteins)
Nerve terminal ending contains SNAPs (synaptosomal nerve associated
proteins)
SNAPs interact with VAMPs
SNAPs + VAMPs collectively- Fusion protein
Main role of both the proteins are in the release of Ach
8.
9. Release
Physiologic release of Ach depends on Ca++ levels.
Due to action potential- Ca++ influx into the neuron-
increase level of Ca++ in the neuron.
Ca++ attaches to VAMPs.
VAMPs helps the vesicle to take certain shapes
Thus vesicles fuses with the membrane.
Membrane ruptures. And Ach is released into the synapse.
(Exocytosis)
10. Metabolism
Ach released from presynaptic neuron goes to postsynaptic neuron
where there are cholinoceptors.
Ach interacts with the receptors, generates action, then dissociates
from receptors.
Dissociated Ach undergoes metabolism with the help of enzyme
Cholinesterase.
Two types of cholinesterase available
• Acetylcholinesterase (AchE): True cholinesterase, Located at all
cholinergic sites, fast in action, terminates action of Ach
• Butyrylcholinesterase(BuchE): Pseudocholinesterase, located in the
plasma, liver and intestine, slow in action, hydrolyses the ingested
ester.
Ach is broken down to Acetyl CoA and Choline
Acetate and choline both have no any transmitter activity.
11. Reuptake
After metabolism, Acetyl CoA is left outside.
Choline is transported back to neuron through choline
transporter.
Certain toxins believed to affect cholinergic transmission:
Hemicholinium: Blocks choline transporter.
Vesamicol: Inhibit VAT transporter.
Botulinum toxin: Inhibit release of Ach
12. 3. Cholinergic receptors
(Cholinoceptors),their locations and
functions
Two classes of receptors of Ach are recognized:
Muscarinic and Nicotinic
Muscarinic- G protein coupled receptors
Nicotinic- Ligand gated ion channels
13. Muscarinic receptors
Stimulated by muscarine, blocked by atropine
Primary locations-
• Heart, blood vessels, eye, smooth muscles and glands of
GI, respiratory and urinary tract, sweat glands, CNS
Muscarinic receptors are classified into 5 sub types (M1-
M5)
First 3 are major subtypes.
M4 and M5 are mainly present on the nerve endings and
few regions of brain, regulating the release of
neurotransmitters.
Functionally- M1, M3, M5 make one class and M2 and M4 a
different class.
15. Nicotinic receptors
These receptors are selectively activated by nicotine and
blocked by tubocurarine or hexamethonium.
They are rosette-like pentameric structures which enclose
a ligand gated cation channel: their activation causes
opening of the channel and rapid flow of cations resulting
in depolarization and an action potential.
On the basis of location and selective agonists and
antagonists two subtypes NM and NN are recognized
17. 4. Drugs acting on cholinergic receptors
i. Cholinergic agonists/ Parasympathomimetics/
Cholinomimetics- These produces their action similar to
that of Ach.
ii. Anticholinesterase- These also produce their action
similar to that of acetylcholine but they increase
availability of Ach.
iii. Anticholinergics/ Parasympatholytics/ Muscarinic
receptor antagonist/ Atropinic- Blocks actions of Ach.
iv. Ganglion blockers- Nicotinic receptor antagonists
18. i. Cholinergic agonists/ Parasympathomimetics/
Cholinomimetics.
Heart- Hyperpolarization of SA node thus, bradycardia
(reduced heart rate) or cardiac arrest
Blood vessels- Dilation
Smooth muscle- contraction, increased in peristalsis,
constriction of bronchial muscles.
Glands- Increased secretion of glands(sweat, salivation, lacrimation).
Eye- Constriction of circular muscles (miosis)
CNS- IV injection of Ach does not cross BBB, hence no central effect
seen.
19. ii Anticholinesterase
Anticholinesterases (anti-
ChEs) are agents which
inhibit ChE.
These protect ACh from
hydrolysis—produce
cholinergic effects.
Some anti ChEs have
additional direct action on
nicotinic cholinoceptors.
Cognitive functions have
been seen to improved in
case of patients suffering
from Alzheimers
administered with AChEs.
21. These are atropine like drugs hence also atropinic.
Actions are opposite to that of cholinomimetic drugs.
CNS- An overall stimulant action seen by atropine. But
Hyoscine produces depressant action even at low doses.
Heart- Tachycardia (increased heart rate) (blockade of M2
receptor)
Eye- Mydriatic effects seen (dilation of pupil)
Smooth muscles- Relaxed, bronchodilation
Glands- Decreased secretion of glands
Body temperature- Rise in body temperature due to
inhibition of sweating.
Local anaesthetic- Mild
23. These were used as an antihypertensive and as anti ulcer
drugs in in the 1950s but now totally replaced due to
number of side effects.
Mecamylamine- Either alone or in combination with
nicotine patch, it has been tried for smoking cessation
There is at present no clinical relevance of ganglion
blockers.
24. References
Essentials of Medical Pharmacology, K.D.Tripathi, 8 Edition
Essentials of Medical Pharmacology, K.D.Tripathi, 7 Edition
Acetylcholinesterase Inhibitors: Pharmacology and
Toxicology, Mirjana B., Aleksandra M. Bondi and Vesna M.
Vasi
Cholinergic Medications, Ramya S. Pakala; Kristen N.
Brown; Charles V. Preuss.
