Pharm Week 3 Flashcards
(20 cards)
Where are sympathetic preganglionic fibers located?
Paravertebral chains on either side of spinal column and prevertebral ganglia on the ventral surface of the aorta
Where are parasympathetic preganglionic fibers located?
In or near the wall of the organ they innervate.
How do the lengths of sympathetic preganglionic fibers compare to lengths of parasympathetic preganglionic? What about post-ganglionic?
Preganglionic sympathetic fibers are short while preganglionic parasympathetic are long. The opposite is true for Post. Post ganglionic sympathetic are long, while parasympathetic are very short.
Where are nicotinic receptors located?
Post-synaptic neurons in ganglia of Parasymp. and symp, adrenal medulla, NMJ, and CNS
Where are muscarinic receptors?
Organs innervated by the PNS, thermoregulatory sweat glands innervated by somatic nervous system.
What enzyme catalyzes the reaction between choline and acetyl-CoA to form ACh?
ChAT: choline acetyltransferase
The neuronal release of ACh into the synapse is inhibited by what toxin?
Botulinum
What organism produced botulinum toxin?
Clostridium Botulinum
The venom of which spiders result in the release of stored ACh into the synpase?
Spiders of the genus Latrodectus - the widow release alpha latrotoxin causes release of Ach into the synaptic cleft.
What are the breakdown products of acteylcholine and what enzyme breaks it down?
Acetylcholine Esterase breaks ACh into choline and acetate.
Mucarine is what?
Muscarine comes from poisonous mushrooms and mimics the effect of acetylcholine.
Where is M1 in the body and name the second messenger system it uses
M1 is found in nerves and gastric parietal cells. It is Gq-coupled, uses IP3 and DAG cascade. Increases intracellular calcium.
Where are M2 receptors found in the body and what is their G-protein system.
M2 receptors are found in nerves, cardiac cells, smooth muscle. Gi inhibits cAMP and opens potassium channels
Where is the M3 receptor in the body and what G protein system does it use?
Smooth muscle, exocrine glands, lungs, GI tract, eye, bladder. Gq coupled system, uses IP3 and DAG cascade, increases intracellular calcium.
Does the PNS directly innervate vasculature.
No, vascular tone is determined by degree of stimulation of adrenergic receptors of sympathetic nervous system. However, there are muscarinic receptors on vasculature.
How does ACh lower blood pressure?
It binds to ACh receptors in the vasculature, leaded to synthesis of Nitric Oxide via a second messenger. This leads to vasodilation and lowering of blood pressure.
What is another name for NO (Nitric oxide)
EDRF = Endothelial-derived relaxation factor
What amino acid is a precursor to NO?
Arginine
Does ACh increase or decrease the following - and which receptors are activated?
- Blood pressure
- Heart Rate
- Salivation
- Lacrimation
- Sweating
- GI secretions
- GI motility
- Miosis
- Bladder detrusor tone
- Bladder sphincter tone
- Bronchodilation
- Blood pressure. ACh causes release of NO, vasodilating and decreasing blood pressure.
- Heart Rate. Decreases heart rate via M2 receptors.
- Salivation. Increases salivation via M3 receptors.
- Lacrimation. Increases via M3 reeptors.
- Sweating. Increases via sympathetic stimulation of muscarinic cholinergic receptors.
- GI secretions. Increases via M3 receptors.
- GI motility. increases via M3 receptors.
- Miosis. Constriction of the pupil due to M3 receptors.
- Bladder detrusor tone. Increases due to M3 receptors.
- Bladder sphinctor tone. Decreases due to M3 receptors.
- Bronchodilation. Decreases via M3 receptors
