Blood Anatomy and Physiology

Front

What are the main functions of blood?

Back

Transports dissolved gases, nutrients, hormones, and metabolic wastes; regulates interstitial fluid pH and ion composition; restricts fluid loss at injury sites; defends against toxins and pathogens; stabilizes body temperature.

Front

What is the composition of whole blood?

Back

Whole blood is a liquid connective tissue containing cells (formed elements) suspended in a fluid matrix (plasma).

Front

What are the three major types of plasma proteins?

Back

1. Albumins: Most abundant (about 60% of all plasma proteins), maintain osmotic pressure of plasma. 2. Globulins: About 35% of plasma proteins, act as transport proteins and antibodies. 3. Fibrinogen: About 4% of plasma proteins, functions in blood clotting as insoluble strands of fibrin.

Front

What are erythrocytes and their main functions?

Back

Erythrocytes, or red blood cells, account for 99.9% of formed elements, contain hemoglobin, transport oxygen and carbon dioxide, have a unique biconcave shape for increased diffusion and flexibility, and are formed through erythropoiesis in red bone marrow.

Front

What is hemoglobin and its role in red blood cells?

Back

Hemoglobin accounts for over 95% of all RBC intracellular proteins, composed of two pairs of globular proteins (subunits), each containing a heme with an iron atom, and is responsible for transporting oxygen and carbon dioxide.

Front

What are leukocytes and their primary functions?

Back

Leukocytes, or white blood cells, are larger than RBCs, help defend the body against pathogens, remove toxins, wastes, and abnormal or damaged cells, and lack hemoglobin.

Front

What are the types of white blood cells?

Back

1. Neutrophils: First WBC to arrive at injury site, active phagocytes. 2. Eosinophils: Phagocytic, attack through exocytosis, increase during parasitic infections. 3. Basophils: Release heparin and histamine. 4. Monocytes: Migrate into tissues and become macrophages. 5. Lymphocytes: Migrate in and out of tissues, some attack foreign cells, others secrete antibodies.

Front

What is the role of platelets in the blood?

Back

Platelets initiate the clotting process and help close injured blood vessels, playing a major role in the clotting system.

Front

What are the three phases of hemostasis?

Back

1. Vascular phase: Contraction in smooth muscle fibers decreases vessel diameter. 2. Platelet phase: Platelets attach to endothelium and form a platelet plug. 3. Coagulation phase: Conversion of fibrinogen to insoluble fibrin forms a blood clot.

Front

What is leukopenia?

Back

Leukopenia is a condition characterized by reduced numbers of white blood cells (WBCs).