Lecture 3 (Quiz 1)

Question 1

The Sympathetic Nervous System has 4 receptors, what are they?

Answer 1

• Alpha-1, Alpha-2, Beta-1 and Beta-2.

Question 2

What are the Agonists of the Sympathetic Alpha-1, Alpha-2 Receptors? What effect does this cause? What are the Antagonists that have these opposite effects?

Answer 2

• A-1, A-2: Epinephrine (higher affinity), Norepinephrine (lower affinity).
  A-1: Phenylephrine
  A-2: Clonidine and Guanfacine.
• A-1 Effect: Contract iris, constrict GI sphincters, constrict vasculature. Increase TPR, Decrease HR.
  A-2 Effect: Decrease NE release in terminals and brainstem, constrict vasculature. Bradycardia (slow heart beat), and dry mouth.
• A-1 Antagonist: Prazosin
• A-2 Antagonist: Yohimbine

Question 3

What are the Agonists of the Sympathetic Beta-1, Beta-2 Receptors? What effect does this cause? What are the Antagonists that have these opposite effects?

Answer 3

• B-1, B-2: Epinephrine (Much higher affinity in B-2 than NE), Norepinephrine, Isoproterenol.
  B-2: Albuterol and Terbutaline.
• B-1 Effect: Increased: HR, Heart conduction and contractility, and velocity of His-Purkinje and Ventricles. (Good for Asthma, and relaxing smooth muscles.)
  B-2 Effect: Relaxed/Dilated vision, vasculature, lungs and bladder.
• Propranolol and Atenolol

Question 4

What is the difference between Eccrine and Apocrine?

Answer 4

• Eccrine: Sweat (temp. regulation)

- Apocrine: Smell/Odor

Question 5

Where is Dopamine (DA) released from? It has two receptors found on different organs/systems (D1, D2), what is the Agonist for both these receptors? What effect does DA have on each of these receptors? There is no Antagonist for the D1 receptor, but what is the Antagonist for the D2 receptor?

Answer 5

• Kidney
• Dopamine (DA)
• D1 Effect: Increased: Blood flow, filtration rate, sodium excretion, vasodilation of the heart and vasculature.
  D2 Effect: Decreased Neurotransmitter release, and Increased nausea and vomiting.
• D2 Antagonist: Haloperidol

Question 6

What receptors are involved with Epinephrine (Adrenaline)? Which receptor distinguishes between EPI and NE? What affect does Epinephrine (Adrenaline) have? What changes does EPI have when given at a low dose, and what does it have when given at a higher dose?

Answer 6

• Alpha 1 and 2, Beta 1 and 2.
• Beta receptors
• Increased HR, ventricular contraction strength and aqueous humor production. Dilates bronchioles and eyes. Relaxes uterus and contracts bladder sphincter.
• Low: Decrease in Total Peripheral Resistance (TPR) and BP.
  High: Increase in Total Peripheral Resistance (TPR) and BP.

Question 7

What are some examples when you would use EPI (5)? What are some side-effects of EPI (3)?

Answer 7

• Bronchospasms, Anaphylaxis, Restore function in Cardiac Arrest, Treat Glaucoma, Prolonged action of local anesthetics.
• Increased HR, Arrhythmias and Anginal pain. Increased TPR and BP. Can lead to pulmonary edema (fluid filled lungs).

Question 8

What receptors does Norepinephrine use? What effects does it cause?

Answer 8

• Alpha 1 and 2, Beta 1 and 2 (however, has a much greater affinity for B1 receptors).
• Vasoconstriction, Increased TPR, Increased BP, Decreased Pulse.

Question 9

What receptors does Dopamine (DA) use? What effect does it have?

Answer 9

• Both Beta and Alpha (higher affinity for Beta than Alpha).

- At high doses, causes an increased BP, TPR, HR and increased organ perfusion. Good to treat shock and heart failure.

Question 10

Mixed Agonists between receptors release NE and are used as a Decongestant, Dietary Supplements, Increase HR, Vasoconstrict and Dilate airways. What are some examples of these mixed Agonists?

Answer 10

• Ephedrine
• Ephedra
• Pseudoephedrine