Cardiovascular System Quiz

Cardiovascular System

• The cardiovascular system includes the heart and blood vessels, bringing nutrients to cells and removing wastes.
• Blood is refreshed in the lungs, kidneys, intestine, and liver, with lymphatic vessels collecting excess fluid and returning it to the cardiovascular system.

Heart and Blood Vessels

• The heart is a large, muscular organ consisting of mostly cardiac tissue (myocardium) surrounded by a sac (pericardium).
• It has two sides (right and left) separated by a septum, with four chambers: two atria and two ventricles.
• The heart has two sets of valves: semilunar valves and atrioventricular valves (AV valves), which produce the "lub" and "dup" sounds when closing and opening.

Blood Vessels

• Arteries carry oxygenated blood away from the heart (except pulmonary artery), with three layers: endothelium, smooth muscle, and outer connective tissue.
• Arterioles are smaller blood vessels that branch off from arteries.
• Veins carry deoxygenated blood toward the heart (except pulmonary vein), with three layers: epithelium, smooth muscle, and outer connective tissue.
• Venules are smaller blood vessels that branch off from veins.
• Veins that carry blood against gravity have valves to keep blood flowing toward the heart.

Capillaries

• Capillaries are microscopic vessels between arterioles and venules, made of one layer of epithelial tissue (endothelium).
• They form beds of vessels where exchange with body cells occurs, with a large surface area surrounding different tissues.

Blood Composition

• Erythrocytes (RBC) contain hemoglobin, an iron-containing protein that transports oxygen.
• Leukocytes (WBC) include:
  • Neutrophils: phagocytosis, bacterial infection
  • Lymphocytes: kill viruses, antibody production
  • Eosinophils: allergy, kill parasites
  • Monocytes: phagocytic function
  • Basophils: release chemicals that trigger inflammation
• All blood cells develop from a common source of stem cells in the red bone marrow.

Cardiovascular Pathways

• Pulmonary circulation: a short loop from the heart to the lungs and back again.
• Systemic circulation: carries blood from the heart to all other parts of the body and back again.

Cardiovascular Diseases

• Atherosclerosis: thickening or hardening of the arteries due to a buildup of plaque (fatty substances, cholesterol, cellular waste products, calcium, and fibrin).
• Heart attack (myocardial infarction): part of the heart dies due to lack of oxygen, often beginning with angina pectoris (pain radiating down the left arm due to a blockage of a coronary artery).

Test your knowledge of the cardiovascular system, including the anatomy of the heart and blood vessels, blood composition and functions, blood flow and pathways, and common cardiovascular diseases.