What is the path of blood through the human body (one full circuit)?
Right atrium → Right ventricle → Pulmonary artery → Lungs (gas exchange) → Pulmonary vein → Left atrium → Left ventricle → Aorta → Body capillaries → Vena Cava → Right atrium.
What chambers make up the heart?
Four chambers: Right atrium, Left atrium, Right ventricle, Left ventricle.
What is the role of atria?
Thin-walled chambers that receive blood returning to the heart.
What is the role of ventricles?
Powerful chambers that pump blood out of the heart.
What is the function of valves in the heart?
Valves prevent backflow and maintain one-way blood flow. Has thick muscle
What is the role of the aorta?
Largest artery; carries oxygen-rich blood from left ventricle to the body.
What is the role of pulmonary arteries?
Carry oxygen-poor blood from right ventricle to lungs.
What is the role of pulmonary veins?
Carry oxygen-rich blood from lungs to the left atrium.
What is the role of capillaries?
Thin walls allow rapid exchange of gases, nutrients, and wastes.
How do arteries differ structurally?
Thick smooth muscle and connective tissue walls.
How do veins differ structurally?
Thinner walls and contain valves to prevent backflow.
How do capillaries differ structurally?
Walls only one cell layer thick for rapid exchange.
What are the components of blood?
Plasma, Red blood cells, White blood cells, Platelets.
What is plasma?
Yellowish liquid with dissolved substances; makes up over half of blood volume.
What are red blood cells (erythrocytes)?
Cells that carry oxygen; lack a nucleus; contain hemoglobin.
What are white blood cells (leukocytes)?
Cells that fight infection.
What are platelets?
Cytoplasmic fragments that help with blood clotting.
What is hemoglobin?
An iron-containing protein in red blood cells that binds oxygen.
How many hemoglobin molecules are in each RBC?
About 250 million molecules per red blood cell.
What is the function of red blood cell shape?
Biconcave shape increases surface area for gas exchange.
Where does hemoglobin bind oxygen?
In pulmonary capillaries (lungs).
Where does hemoglobin release oxygen?
In systemic capillaries (body tissues).
What factors interfere with hemoglobin’s ability to transport oxygen?
Iron deficiency (anemia), carbon monoxide poisoning, genetic differences (e.g., sickle-cell).
What is the path of oxygen from environment to body tissues?
Inhaled into lungs → diffuses from alveoli into capillaries → transported via pulmonary vein to left atrium → left ventricle → aorta → systemic circulation → diffuses into body tissues.
