Circulatory System Blood 4e NOTES Fall 2022 (1)

Circulatory System

Network of blood vessels, the heart, and blood that sustains life by transporting oxygen, nutrients, and waste.

Heart

Muscular pump with four chambers (two atria, two ventricles) that facilitates blood circulation.

Blood Vessels

Include arteries, veins, and capillaries responsible for transporting blood to and from the heart.

Arteries

Thick-walled vessels carrying oxygenated blood away from the heart (except for pulmonary arteries).

Veins

Thinner-walled vessels returning deoxygenated blood to the heart (except for pulmonary veins).

Capillaries

Tiny vessels where gas, nutrient, and waste exchange occurs between blood and tissues.

Transportation Functions

Transport oxygen, carbon dioxide, nutrients, metabolic wastes, and hormones throughout the body.

Protection Functions

Offers immunity through white blood cells and antibodies, and prevents blood loss via clotting mechanisms.

Regulation Functions

Regulates fluid balance, pH, and body temperature through blood flow.

Blood Composition

Composed of plasma (55%) and formed elements (45%), including red and white blood cells, and platelets.

Erythrocytes

Red blood cells containing hemoglobin for oxygen transport; characterized by a biconcave shape.

Leukocytes

White blood cells less than 1% of blood, essential for the immune response, categorized as granulocytes and agranulocytes.

Platelets

Cell fragments involved in hemostasis, playing a key role in blood clotting.

Plasma Composition

Made up of 92% water and 7% proteins (albumin, globulins, fibrinogen), along with solutes like electrolytes and gases.

Hemostasis

Process of blood clotting involving vascular spasm, platelet plug formation, and coagulation.

Vascular Spasm

Immediate constriction of blood vessels post-injury to minimize blood loss.

Platelet Plug Formation

Adhesion of platelets to collagen at injury sites to form a temporary plug.

Coagulation

Conversion of fibrinogen to fibrin, creating a mesh to stabilize clots.

ABO Blood Groups

Blood type classification based on the presence of A and B antigens on red blood cells.

Type A Blood

Contains antigen A on red blood cells.

Type B Blood

Contains antigen B on red blood cells.

Type AB Blood

Contains both A and B antigens; universal recipient.

Type O Blood

Contains neither antigen; universal donor.

Rh Factor

Presence (Rh-positive) or absence (Rh-negative) of D antigen on red blood cells.