11 Questions
Which division of the autonomic nervous system is responsible for the 'Rest and Digest' response?
Parasympathetic nervous system
Which neurotransmitter is predominantly involved in the sympathetic nervous system?
Norepinephrine
Which of the following organs receives ONLY sympathetic innervation?
Heart
What are the two main types of adrenergic receptors in the sympathetic nervous system?
Alpha and Beta receptors
Which muscle is NOT directly innervated by parasympathetic nerves?
Heart muscle
What are the 5 steps involved in cholinergic neurotransmission?
Synthesis, storage, release, binding, reuptake
Which of the following statements about the storage and synthesis of acetylcholine (ACh) is correct?
VAChT is an antiporter that actively transports synthesized ACh into the vesicles.
Which of the following correctly describes the release of ACh from the presynaptic neuron?
ACh is released by exocytosis triggered by $Ca^{2+}$ entry upon arrival of a nerve impulse.
Which of the following correctly identifies the site of action of the drug tubocurarine?
It blocks the nicotinic cholinergic receptors.
Which of the following statements about the termination of acetylcholine (ACh) activity is correct?
ACh activity is terminated by the enzyme acetylcholinesterase (AChE), which is blocked by neostigmine.
Which of the following correctly identifies the site of action of the drug hemicholinium?
It blocks the high-affinity choline transporter (HAChT).
Study Notes
Autonomic Pharmacology
- Study of how drugs interact with the Autonomic Nervous System (ANS)
Synthesis & Metabolism of Acetylcholine (ACh)
- ACh is synthesized from choline and acetyl-CoA by the enzyme choline acetyltransferase (ChAT)
- Synthesized ACh is actively transported into vesicles by vesicular acetylcholine transporter (VAChT), an antiporter
- ACh is released from vesicles by exocytosis triggered by Ca2+ entry upon arrival of nerve impulse
- Once released, ACh diffuses across the synaptic cleft to bind with cholinergic receptors on postsynaptic membrane (sometimes presynaptic)
Cholinergic Receptors
- Cholinergic receptors are bound by ACh, blocked by atropine (M) or tubocurarine (N)
Termination of ACh
- ACh is terminated by acetylcholinesterase (AChE), blocked by neostigmine
- High-affinity choline transporter (HAChT) is blocked by hemicholinium
Sites of Drug Action at Cholinergic Neuron
- ChAT is blocked by naphthylvinylpyridine (NVP)
- VAChT is blocked by vesamicol
- ACh release is blocked by botulinum toxin (involves SNAP and VAMP)
Autonomic Nervous System (ANS)
- Divided into two divisions: Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PNS)
- SNS: "Fight or Flight" response, neurotransmitter is norepinephrine (NA), receptors are α and β adrenoceptors
- PNS: "Rest and Digest" response, neurotransmitter is acetylcholine (ACh), receptors are muscarinic and nicotinic receptors
Thoracolumbar Outflow (Sympathetic)
- Organs receiving only sympathetic innervation:
- Radial muscle of iris
- Muller's muscle
- Heart
- Arrector pili muscles
- Sweat glands
- Bronchiole (gland and smooth muscle)
- Stomach
- Most blood vessels
- Spleen
- Adipose tissue
- Paravertebral ganglia
- Adrenal medulla
- Kidney
- Intestines
- Bladder
- Prevertebral ganglia
- Ejaculation muscle
Craniosacral Outflow (Parasympathetic)
- Organs receiving only parasympathetic innervation:
- Heart
- Bronchiole (smooth muscle and gland)
- Stomach
- Small intestine
- Lacrimal gland
- Sphincter (circular) muscle of iris
- Ciliary muscle
- Salivary gland
- Large intestine
- Bladder
- Genitalia
Test your knowledge on the synthesis and metabolism of acetylcholine in the Autonomic Pharmacology field. This quiz covers topics such as Cholinergic & Acetylcholinesterase, Anticholinergic & NMJ Blocker, and Sympathomimetic drugs. Get ready to challenge yourself with questions related to ANS interactions with drugs.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
