Week 9: Ch. 13-16 ANS [Cholinergic & Adrenergic Agonists & Antagonists]

Question 1

Cholinergic receptors located throughout peripheral
nervous system

– At ___________ junctions in parasympathetic
division
– At _________ in both parasympathetic and sympathetic
divisions

Answer 1

– At neuroeffector junctions in parasympathetic
division
– At ganglia in both parasympathetic and sympathetic
divisions

Question 2

Cholinergic receptors located in somatic nervous system
– At ___________ _________

Answer 2

neuromuscular junctions

Question 3

• Cholinergic agonists (aka Parasympathomimetics)
  – Drugs that increase action of ______________________, promoting rest-and-digest responses

Answer 3

– Drugs that increase action of ACh at cholinergic
receptors, promoting rest-and-digest responses

Question 4

• Cholinergic agonists (aka Parasympathomimetics)
  – Primary types : [2]

Answer 4

▪Muscarinic agonist
▪Nicotinic agonist

Question 5

• Direct cholinergic agonists
  – Produce _____________ responses
  – Activate cholinergic synapses by releasing ACh into the synaptic cleft
  – Drug binds to ACh receptors, enhancing _______________
  – Drug inactivated by AChE

Answer 5

– Produce rest-and-digest responses
– Activate cholinergic synapses by releasing ACh into the synaptic cleft
– Drug binds to ACh receptors, enhancing action potential
– Drug inactivated by AChE

Question 6

• Indirect-acting drugs
  – Inhibit acetylcholinesterase _________ (cholinesterase)
  – Neurotransmitter accumulates and remains in synaptic cleft for ________2_________

Answer 6

(AChE)

2- longer time.

Question 7

▪Physiologically it does not matter whether cholinergic synapse activated directly or indirectly.
▪Parasympathetic responses:

Answer 7

the same.

Question 8

• Indirect-acting cholinergic agonists – Acetylcholinesterase (AChE) inhibitors

▪_____________and affect ACh synapses located at autonomic ganglia, muscarinic receptors neuromuscular junctions, and ACh synapses in the
CNS

Answer 8

Nonselective

Question 9

• Indirect-acting cholinergic agonists – Acetylcholinesterase (AChE) inhibitors

Medications
▪Increase __________ in GI, urinary tracts
▪Some can _______ intraocular pressure

Answer 9

Medications
▪Increase peristalsis in GI, urinary tracts
▪Some can decrease intraocular pressure

Question 10

____________ ________
– Can be caused by overdose of medications, toxic gases, or insecticides
– Causes intense miosis, nausea, vomiting, urinary incontinence, increased exocrine secretions, abdominal cramping, and diarrhea
– Can also cause tachycardia, hyperglycemia, muscle weakness, flaccid paralysis
– Treated with atropine or pralidoxime to reverse muscarinic effects

Answer 10

• Cholinergic crisis

Question 11

• Myasthenia gravis
  – Literally “__________________ weakness”
  – Considered a _________ disease
  – Causes muscle weakness, difficulty in chewing, swallowing, speech, and vision

Answer 11

– Literally “grave muscular weakness”
– Considered a progressive disease
– Causes muscle weakness, difficulty in chewing,
swallowing, speech, and vision

Question 12

• Myasthenic crisis
  – May occur if patient with MG abruptly ___________________
  – Extreme muscular weakness and symptoms similar to ____________
  – Rapid, correct diagnosis essential

Answer 12

– May occur if patient with MG abruptly discontinues medication
– Extreme muscular weakness and symptoms similar to cholinergic crisis
– Rapid, correct diagnosis essential

Question 13

Nicotinic Agonists
* Nicotine only drug used widely to activate:

Answer 13

ganglionic receptors

Question 14

Nicotinic Agonists
Used primarily in nicotine replacement therapy (NRT) for ______________________
– Goal to gradually reduce patient’s _______________________

Answer 14

Used primarily in nicotine replacement therapy (NRT) for tobacco cessation
– Goal to gradually reduce patient’s physical dependence on nicotine

Question 15

• Cholinergic antagonists
  – Inhibit the action of ACh at _________________
  – Drug action dependent on site of action

– Two types
??
??

Answer 15

– Inhibit the action of ACh at cholinergic synapses
– Drug action dependent on site of action

– Two types
▪Muscarinic
▪Nicotinic

Question 16

Muscarinic antagonists
– Primarily block receptors in _______________________
– May also be known as anticholinergics, cholinergic blockers, muscarinic antagonists, or parasympatholytics
– Work by competing with ____ for binding at muscarinic receptors, allowing sympathetic activation to predominate

Answer 16

– Primarily block receptors in parasympathetic nervous system
– May also be known as anticholinergics, cholinergic blockers, muscarinic antagonists, or parasympatholytics
– Work by competing with ACh for binding at muscarinic receptors, allowing sympathetic activation to predominate

Question 17

Nicotinic Antagonists: Ganglionic Blockers

• Interrupt transmission of nerve impulses at _______________
• Nonselectively inhibit ______
• Affect parasympathetic system more than sympathetic
• Work to lower blood pressure in emergency situations
• ___________ is only therapeutic use.
• Only one ganglionic blocker, mecamylamine (Vecamyl), is approved for use.

Answer 17

• Interrupt transmission of nerve impulses at nicotinic receptors
• Nonselectively inhibit ANS
• Affect parasympathetic system more than sympathetic
• Work to lower blood pressure in emergency situations
• Vasodilation is only therapeutic use.
• Only one ganglionic blocker, mecamylamine (Vecamyl), is approved for use.

Question 18

Adrenergic Agonists

• Induce _________________ response
  – May be therapeutic or adverse depending on
  patient’s condition
• Two receptor types
  ??
  ??
• Wider therapeutic applications due to lower incidence of adverse effects

Answer 18

• Induce fight-or-flight response
  – May be therapeutic or adverse depending on
  patient’s condition
• Two receptor types
  – Alpha
  – Beta
• Wider therapeutic applications due to lower incidence of adverse effects

Question 19

• Catecholamines
  – _______ duration of action
  – Destroyed rapidly by monoamine oxidase (MAO) and COMT
  – Cannot be given __________
  – Must be given parenterally or by inhalation
  – Do not cross _____________ barrier

Answer 19

– Short duration of action
– Destroyed rapidly by monoamine oxidase (MAO) and COMT
– Cannot be given orally (PO)
– Must be given parenterally or by inhalation
– Do not cross blood-brain barrier

Question 20

• Noncatecholamines
  – May be taken _____________
  – Not destroyed as readily by MAO or COMT
  – Better able to enter ________ and affect CNS

Answer 20

– May be taken orally (PO)
– Not destroyed as readily by MAO or COMT
– Better able to enter brain and affect CNS

Question 21

Alpha-Adrenergic Agonists
* Used to treat ____________ associated with shock
* Treatment of patient susceptible to orthostatic hypotension
* Treatment of nasal congestion
* Topical instillation of alpha1 agonists to eye
– Examining interior structures
– Relieving conjunctival congestion, redness

Answer 21

• Used to treat hypotension associated with shock
• Treatment of patient susceptible to orthostatic hypotension
• Treatment of nasal congestion
• Topical instillation of alpha1 agonists to eye
  – Examining interior structures
  – Relieving conjunctival congestion, redness