IASM 84: Drugs on Sympathetic Nervous System Flashcards
Sympathetic Nervous System
Preganglionic Neuron releases _____ as neurotransmitter
Postganglionic Neuron releases _____ as the MAJOR neurotransmitter
Sympathetic Nervous System
Preganglionic Neuron releases Ach as neurotransmitter
Postganglionic Neuron releases NE as the MAJOR neurotransmitter
What are the functions of the following receptors Alpha-1 Alpha-2 Beta-1 Beta-2
What are the functions of the following receptors
Alpha-1: Vasoconstriction, Constriction of smooth muscle
Alpha-2: Decrease presynaptic NE release
Beta-1: Increase contractility of heart and Increase Heart Rate
Beta-2: Vasodilation, Relaxation of Smooth Muscle
Blood Pressure Calculation
Resistance
Stroke Volume
Heart Rate
Heart Rate x Stroke Volume x Peripheral Resistance
What receptors control the following?
Resistance
Stroke Volume
Heart Rate
Resistance- A1, B2
Stroke Volume- B1
Heart Rate- B1 and also reflex
Reflex: When vessels are over constricted, baroreceptors send signal to brain. Brain will activate the parasympathetic system, leads to bradycardia
Adrenaline is a non-selective agonist
- Affinity of Adrenaline is stronger to A1 or B2?
- So overall, is there vasodilation or constriction?
- Overall, is there increase in blood pressure? How much?
- Name 2 clinical uses
Adrenaline is a non-selective agonist
- Affinity of Adrenaline is stronger to A1 or B2? B2
- So overall, is there vasodilation or constriction? Vasodilation
- Slight increase in BP
- Name 2 clinical uses: Anaphylactic shock + Cardiac Arrest
Compare the A1 and B2 receptors in
- Smooth muscles
- Blood vessels
- Does adrenaline has higher affinity to A1 or B2
Compare the A1 and B2 receptors in
- Smooth muscles: B2 > A1
- Blood vessels: A1 > B2
- Adrenaline affinity: B2 > A1
Compare the A1 and B2 receptors in
- Smooth muscles
- Blood vessels
- Does noradrenaline has higher affinity to A1 or B2
Compare the A1 and B2 receptors in
- Smooth muscles: B2 > A1
- Blood vessels: A1 > B2
- Noradrenaline affinity: A1 > B2
Rmb Noradrenaline will cause upupup in BP
Noradrenaline is a non-selective agonist
- Affinity of noradrenaline is stronger to A1 or B2?
- So overall, is there vasodilation or constriction?
- Overall, is there increase in blood pressure? How much?
- What will happen afterwards
- Name 1 clinical use
noradrenaline is a non-selective agonist
- Affinity of Noradrenaline is stronger to A1 or B2? A1
- So overall, is there vasodilation or constriction? Vasoconstriction
- Large increase in BP
- What will happen afterwards: Reflex Bradycardia
- Name 1 clinical use: Hypotension
Name 2 Selective A1 Agonists
Overall influence on BP
Name 1 clinical use
Phenylephrine, Oxymetazoline
Increase BP
Decongestant to reduce mucosal swelling
Name 1 Selective A2 Agonist
Overall influence on BP
Name 1 clinical use
Clonidine
Decrease BP
Migraine
Name 1 non Selective B Agonist
Overall influence on BP
Why is it not used for asthma anymore?
Isoproterenol
Decrease BP (Need to memorize, Stimulate B2 to greater extent)
Side effect of increasing heart rate for asthma patients
Note: Both Non-selective B agonist and Non-selective B antagonist decrease the blood pressure
Name 1 Selective B1 Agonist
Overall influence on BP
Name 1 clinical use
Dobutamine
Increase BP
Hypotension/ Heart failure
Name 2 Selective B2 Agonists
Overall influence on BP
Name 1 clinical use
Terbutaline, Salbutamol
Decrease BP
Asthma
Name 1 Selective B3 Agonist
Where are B3 receptors
Name 1 clinical use
Mirabegron
B3 receptors are found in urinary bladder and fat cells
Overactive bladder
Name 1 non Selective A Antagonists
What will it result
Name 1 clinical use
Phenoxybenzamine
Reflex tachycardia
Phaeochromocytoma
