Blood Composition and Functions

Flashcards covering key terms and definitions related to blood composition and functions.

Blood

The fluid that transports oxygen, nutrients, and substances throughout the body, involved in clotting and fighting infections.

Erythrocytes

Red blood cells responsible for transporting oxygen; they contain hemoglobin.

Leukocytes

White blood cells that defend the body against infections and diseases.

Platelets

Cell fragments that play a key role in blood clotting.

Plasma

The liquid component of blood, consisting of water, proteins, and other substances.

Hematocrit

The percentage of blood volume that is occupied by red blood cells.

Hemoglobin

An iron-containing protein in red blood cells that binds to oxygen for transport.

Anemia

A condition characterized by a decrease in red blood cell count or hemoglobin, leading to reduced oxygen-carrying capacity.

Polycythemia

An excessive increase in red blood cell number, often leading to increased blood viscosity.

Hemostasis

The process of stopping bleeding, involving blood vessel constriction, platelet plug formation, and clotting.

Erythropoietin

A hormone produced by the kidneys that stimulates red blood cell production in response to low oxygen levels.

Diapedesis

The process by which white blood cells move out of blood vessels into tissues.

Chemotaxis

The movement of cells towards a chemical signal, often in response to infection or injury.

Homeostasis

The body's ability to maintain stable internal conditions, despite external changes.

Fibrin

A protein that forms a mesh-like structure to help in blood clotting.

Buffy coat

The thin layer of white blood cells and platelets between plasma and red blood cells after blood is centrifuged.

Composition of Whole Blood

Whole blood consists of formed elements and plasma, making up approximately 8% of body weight.

Plasma Composition

Plasma is the liquid component of blood, constituting about 55% of its volume, and contains water, proteins, hormones, and nutrients.

Formed Elements of Blood

The formed elements include erythrocytes (red blood cells), leukocytes (white blood cells), and platelets, each with specific functions.

Anemia

A condition characterized by a deficiency in red blood cells or hemoglobin, leading to decreased oxygen transport.

Polycythemia

An increase in red blood cells, which can increase blood viscosity and affect circulation.

Leukopenia

A condition marked by a low white blood cell count, which can impair the immune response.

Leukocytosis

An increase in white blood cell count, often indicative of infection or inflammation.

Hemocytoblast

A stem cell in the bone marrow that gives rise to all types of blood cells.

Hemostasis

The process of blood clotting, which involves vascular spasm, platelet plug formation, and coagulation.

ABO Blood Groups

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

Rh Blood Groups

A blood group system based on the presence or absence of the Rh antigen, important for blood transfusions.

Transfusion Reaction

A potentially serious immune response that occurs when a patient receives incompatible blood during a transfusion.

Heart Anatomy

The heart consists of four chambers (atria and ventricles) and valves that prevent backflow, crucial for blood circulation.

Pulmonary Circulation

The circuit of blood flow from the heart to the lungs and back, where gas exchange occurs.

Systemic Circulation

The movement of oxygen-rich blood from the heart to the body and oxygen-poor blood back to the heart.

Intrinsic Conduction System

The group of specialized heart cells (SA node, AV node, Purkinje fibers) that regulates heartbeat.

Electrocardiogram (ECG)

A test that measures the electrical activity of the heart, capturing heart rhythm and abnormalities.

Systole

The phase of the heart cycle during which the ventricles contract and pump blood.

Diastole

The phase of the heart cycle when the heart muscle relaxes and fills with blood.

Stroke Volume

The amount of blood pumped by each ventricle with each heartbeat.

Cardiac Cycle

The sequence of events in a single heartbeat, including both contraction and relaxation phases.

Blood Vessel Structure

Arteries have thick walls for high pressure; veins have valves to prevent backflow; capillaries are thin for exchange.

Pulse Points

Locations on the body where the pulse can be felt, indicating heart rate, such as at the wrist and neck.

Blood Pressure

The force exerted by circulating blood on the walls of blood vessels, typically measured in mm Hg.

Hypertension

A condition characterized by persistently high blood pressure, increasing the risk of heart disease and stroke.

Atherosclerosis

A condition where fatty deposits build up in artery walls, potentially leading to blocked blood flow.

Capillary Exchange

The process through which gases, nutrients, and wastes are exchanged between blood and tissues through capillary walls.

Cellular Respiration

The metabolic process by which cells use oxygen to produce energy from glucose and releases carbon dioxide.

Pulmonary Ventilation

The process of moving air into and out of the lungs during breathing.

Respiratory Volumes

Measurements of air volumes during breathing, such as tidal volume and vital capacity, important for assessing lung function.