Cardiovascular System Overview

Study Notes

A closed system of blood vessels responsible for delivering oxygenated blood to tissues and removing waste products.
Blood flow occurs from higher pressure to lower pressure areas.
Moves blood throughout the body.

Controlled by areas of the brain and various hormones.
High blood pressure = Hypertensive.
Low blood pressure = Hypotensive.
Severe low blood pressure is called Hypovolemic Shock and is life-threatening.
Drug therapy aims to maintain blood pressure within normal limits.
Determined by:
- Amount of blood the heart pumps.
- Amount of resistance to blood flow in arteries.
Higher blood pressure is related to increased blood pumped by the heart and narrower arteries.

Renin: An enzyme secreted by the juxtaglomerular cells in response to low blood pressure, sodium levels, or stimulation from the sympathetic nervous system.
Angiotensin: A protein produced by the liver, converted into angiotensin I by renin.
Angiotensin I: An inactive precursor converted into angiotensin II by angiotensin-converting enzyme (ACE) in the lungs.
Angiotensin II: A potent vasoconstrictor, increasing blood pressure and stimulating aldosterone release from the adrenal glands.
Aldosterone: A hormone promoting sodium and water retention by the kidneys, ultimately increasing blood pressure.
Antidiuretic Hormone (ADH): Released from the pituitary gland, also helps the kidneys retain water.

Block the action of angiotensin-converting enzyme (ACE), preventing angiotensin II formation.
Lower blood pressure by reducing vasoconstriction and aldosterone release.

Block the action of angiotensin II by preventing it from binding to its receptors.
Lower blood pressure by reducing vasoconstriction and aldosterone release.

Block alpha-1 receptors in the blood vessels, causing vasodilation (relaxation of blood vessels).
Reduce blood pressure by decreasing peripheral resistance.

Lower blood pressure primarily by blocking the sympathetic activation of beta-1 receptors in the heart.
Block beta-1 receptors in the heart, preventing sympathetic catecholamines (norepinephrine and epinephrine) from binding.
Result in decreased heart rate, stroke volume, cardiac output, and blood pressure.

A long-term force of blood against arterial walls.
Can cause problems like heart disease (coronary artery and cardiovascular disease).

A condition where arteries become narrowed and hardened due to plaque buildup (fats) in the artery wall.

A pattern of arteriosclerosis characterized by the development of lesions in the walls of arteries.
Involves the gradual buildup of plaque in the walls of arteries.
Plaque is composed of fats, cholesterol, calcium, and other substances.