Cardio 4

Question 1

What mechanisms increase venous return?

Answer 1

Increases in sympathetic activity, compression from skeletal muscles, and ventilation.

Question 2

How does norepinephrine affect blood vessels and the heart?

Answer 2

Norepinephrine causes vasoconstriction by acting on alpha-1 receptors and increases frequency and force of cardiac contraction by acting on beta-1 receptors.

Question 3

What effect does epinephrine have on blood vessels?

Answer 3

Epinephrine causes vasodilation in certain areas by acting on beta-2 receptors.

Question 4

How can acetylcholine affect blood vessels?

Answer 4

Acetylcholine can cause vasodilation by acting on M3 receptors in very few areas like the genitalia.

Question 5

How is blood flow redistributed during different physiological demands?

Answer 5

Through differential autonomic pharmacology: blood flow is directed to skeletal muscle and heart, while reduced to skin and GI tract.

Question 6

What are the key mechanisms regulating vascular tone?

Answer 6

Autonomic nervous system and renin-angiotensin system. Vasoconstriction via norepinephrine (alpha-1) or angiotensin II (AT1 receptors); vasodilation via epinephrine (beta-2) or ACh (M3).