Overview of the Circulatory System

Red Blood Cells

• Red blood cells, also known as erythrocytes, are the primary carriers of oxygen throughout the body.
• They contain hemoglobin, a protein that binds to oxygen in the lungs and releases it in the tissues.

Cardiovascular Conditions

• A heart attack, or myocardial infarction, occurs when blood flow to the heart is blocked, often due to a clot in a coronary artery.

Lymphatic System

• The lymphatic system plays a crucial role in regulating fluid balance by collecting excess fluid from tissues and returning it to the bloodstream.

Blood Vessel Diameter

• While factors like hormones, nervous system signals, and local tissue conditions influence blood vessel diameter, the color of blood does not directly impact it.

Blood Transfusions

• Matching donor and recipient blood types is crucial during transfusions to prevent immune reactions, such as agglutination (clumping of red blood cells), which can be life-threatening.

Circulatory System

• The primary function of the circulatory system is to transport oxygen, nutrients, and hormones throughout the body, while also removing waste products like carbon dioxide.

Capillaries

• Capillaries are the smallest blood vessels, forming a network that connects arteries and veins.
• They are responsible for the exchange of gases, nutrients, and waste products between the blood and tissues.

Blood Pressure

• Blood pressure is the force exerted by blood against the walls of arteries.
• It is typically measured as systolic pressure (during contraction of the heart) and diastolic pressure (during relaxation of the heart).

Pulmonary Circulation

• In pulmonary circulation, deoxygenated blood from the heart travels to the lungs to pick up oxygen and release carbon dioxide. This oxygenated blood then returns to the heart.

Oxygen Carrying Component

• Red blood cells are primarily responsible for carrying oxygen throughout the body due to their high concentration of hemoglobin.

Heart Valves

• Heart valves ensure unidirectional blood flow through the heart by opening and closing to prevent backflow.

Pacemaker

• The sinoatrial node (SA node), located in the right atrium, is known as the heart's pacemaker as it generates electrical impulses that regulate the heart's rhythm.

Plasma Composition

• Blood plasma, the liquid component of blood, is primarily composed of water, but also contains proteins, electrolytes, nutrients, and waste products.