Functions and Characteristics of Blood

These flashcards cover the various functions, components, and characteristics of blood, including descriptions of blood cells, plasma, and related disorders.

Functions of Blood

Blood transports oxygen and carbon dioxide, delivers nutrients, hormones, and removes metabolic wastes. It protects the body through immune responses and prevents excessive blood loss through clotting.

Components of Blood

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

Hematocrit

The percentage of whole blood that is made up of red blood cells; normal levels range from 42–56% in males and 38–46% in females.

Physical Characteristics of Whole Blood

Whole blood appears bright red when oxygenated, darker when deoxygenated, has a higher temperature than the body, is viscous, and has a pH of 7.35 to 7.45.

Plasma

The liquid portion of blood, comprising about 55% of blood volume; it is mainly water and contains proteins, electrolytes, nutrients and waste products.

Formed Elements

Cellular components of blood, including red blood cells, white blood cells, and platelets; only white blood cells are complete cells.

Erythrocytes

Another term for red blood cells, which are biconcave discs that transport oxygen and carbon dioxide.

Erythropoiesis

The production of red blood cells, mainly regulated by oxygen levels in the blood and the hormone erythropoietin (EPO).

Destruction of Red Blood Cells

Red blood cells last about 120 days and are removed by macrophages; hemoglobin is broken down, recycled, or converted to bilirubin.

ABO Blood Group

A classification of blood based on the presence of A and B antigens on red blood cells; mixing incompatible types can cause clumping.

Anemia

A condition with too few red blood cells or not enough hemoglobin, leading to decreased oxygen transport, fatigue, and weakness.

Polycythemia

A condition of having too many red blood cells, increasing blood viscosity and clot risk; can be caused by low oxygen levels or bone marrow disorders.

Types of Leukocytes

White blood cells including neutrophils, eosinophils, basophils, lymphocytes, and monocytes, each with specific immune functions.

Phagocytosis

The process by which phagocytic cells engulf and destroy pathogens, enclosing them in vesicles.

Leukopenia

A low white blood cell count that weakens the immune system, increasing infection risk.

Leukemia

A cancer of white blood cells that crowds out normal cells, causing anemia and bleeding risks.

Platelets

Cell fragments from megakaryocytes, important for clot formation and preventing blood loss.

Hemostasis

The process to prevent blood loss from damaged vessels, involving vascular spasm, platelet plug formation, and coagulation.

Thrombosis

The formation of an abnormal blood clot within a blood vessel; a thrombus is an attached clot, while an embolus is a clot that travels.

Hemophilia

A genetic disorder causing deficiencies in clotting factors, leading to impaired clotting and prolonged bleeding.