Term
| Explain the autonomic control that causes the bladder to fill |
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Definition
Sympathetic innervation using beta 2 receptors causes the detrusor muscle (bladder wall) to relax
Sympathetic innervation using alpha 1 receptors causes the internal sphincter (trigone) to contract
Also voluntary control causes the external sphincter to contract |
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Term
| Explain the autonomic control that causes the bladder to empty |
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Definition
Parasympathetic innervation causes
-the detrusor muscle (bladder wall) to contract
-the internal sphincter (trigone) to relax
Also voluntary control causes the external sphincter to relax |
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Term
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Definition
Nicotine is a nicotinic receptor agonist.
It stimulates nicotinic receptors on the postganglionic cell bodies of neurons |
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Term
| What do diisopropyl fluorophosphate (DFP), physostigimine, and neostigimine do? |
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Definition
They are all inhibitors of acetylcholinesterase at postganglionic cell bodies
They prevent the breakdown of Ach which leads to increased Ach activity
Note - DFP is nerve gas |
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Term
| What does hexamethonium do? |
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Definition
It blocks conduction at the nicotinic receptors of the postganglionic cell bodies
It causes relaxation and vasodilation
Remember it only blocks nicotinic receptors at the ganglion and not ones on skeletal muscle |
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Term
| What do ephedrine, amphetamine, and cocaine do? |
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Definition
| They act at the endings of postganglionic noradrenergic nuerons and augment the release of norepinephrine. |
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Term
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Definition
It interferes with NE storage
By inhibiting NE storage it leads to less NE being released and depressed sympathetic activity |
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Term
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Definition
It is an agonist of muscarinic receptors
It increases PNS activity |
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Term
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Definition
It is an antagonist of muscarinic receptors
It blocks PNS effects
Used as a pre-surgery drug - blocks salivation and respiratory system secretions
Also used to cause pupil dilation |
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Term
| What does phenylephrine do? |
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Definition
It stimulates alpha 1 receptors
It is an OTC drug used for colds, allergies, and nasal congestion |
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Term
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Definition
It is an agonist of alpha 2 receptors
It prevents NE release
It is used as an anti-hypertension drug because it leads to vessel relaxation and decreased BP |
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Term
| What do phenoxybenzamine (dibenzyline) and phentolamine (regitine) do? |
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Definition
| They are antagonists of alpha 1 receptors |
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Term
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Definition
| It is an antagonist of alpha 2 receptors |
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Term
| What does propranolol do? |
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Definition
It is a beta blocker
It attaches to beta 1 receptors and reduces HR and prevents arrhythmias |
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Term
| What does isoproterenol (isuprel) do? |
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Definition
| It stimulates beta receptors |
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Term
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Definition
| It stimulates nicotinic receptors |
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Term
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Definition
It competitively inhibits ACh activity at nicotinic receptors
It competes with ACh for the nicotinic receptor |
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Term
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Definition
Pheochromocytoma is a tumor of the adrenal medulla
It causes excessive amounts of NE and EPI to be secreted
This leads to excessive SNS activity and symptoms such as extremely high HR and BP and cold hands and feet (vasoconstriction of the vascular smooth muscle of the skin)
Treatment consists of excising the tumor and getting rid of the source. If the tumor cannot be removed then alpha 1 and beta 1 antagonists are used |
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Term
| What is adrenal neuroblastoma? |
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Definition
Adrenal tumor common in infants that can displace other organs
It causes excessive catecholamine release |
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Term
| What can cause tachycardia, mydriasis, dry mouth, and difficulty voiding urine? |
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Definition
A muscarinic antagonist
PNS innervation of the heart would be inhibited causing increased HR - tachycardia
Constriction of the pupil would be blocked causing pupil dilation - mydriasis
Saliva production would be inhibited causing dry mouth
Contraction of the detrusor muscle and relaxation of the internal sphincter would be blocked causing the difficulty of emptying the bladder |
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Term
| What is neostigmine used for? |
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Definition
| Because it inhibits acetylcholinesterase, it is used in the treatment of myasthenia gravis |
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Term
| What is the function of tricyclic antidepressants? |
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Definition
| They prolong NE activity on postsynaptic membranes |
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