anatomy honors heart and blood

Blood

A fluid connective tissue made of plasma, red blood cells, white blood cells, and platelets. Purpose: Transports oxygen, nutrients, hormones, and wastes; protects against infection and regulates temperature. Found: Inside blood vessels and the heart.

Plasma

The liquid portion of blood, made mostly of water (about 90%), proteins, nutrients, hormones, electrolytes, and wastes. Purpose: Transports blood cells and dissolved substances. Found: In blood.

Water

A molecule made of hydrogen and oxygen (H2O). Purpose: Dissolves and transports nutrients, hormones, gases, and wastes; regulates temperature. Found: Throughout the body, especially in plasma and cells.

Albumins

Proteins produced by the liver. Purpose: Maintain blood osmotic pressure and transport substances. Found: Blood plasma.

Globulins

A group of plasma proteins, including transport proteins and antibodies. Purpose: Transport substances and help defend against infection. Found: Blood plasma.

Antibodies

Proteins produced by plasma cells (activated B lymphocytes). Purpose: Recognize and bind to specific antigens to help fight pathogens. Found: Blood plasma, lymph, and other body fluids.

Hemoglobin

An iron-containing protein made of four protein chains with heme groups. Purpose: Carries oxygen and helps transport some carbon dioxide. Found: Inside red blood cells.

Biconcave Disc

The flattened, indented shape of a red blood cell. Purpose: Increases surface area for gas exchange and allows cells to squeeze through tiny capillaries. Found: Red blood cells.

Oxygen

An element (O) carried mostly by hemoglobin. Purpose: Needed for cellular respiration to produce ATP. Found: Lungs, blood, and body tissues.

Nucleus

A cell structure containing DNA. Purpose: Controls cell activities and stores genetic information. Found: Most human cells; mature red blood cells do not have one.

Leukocytes

White blood cells produced through hematopoiesis. Purpose: Protect the body against pathogens and infections. Found: Blood, lymph, and body tissues.

Monocytes

A type of white blood cell produced in bone marrow. Purpose: Engulf pathogens and dead cells; can develop into macrophages or dendritic cells. Found: Blood and body tissues.

Eosinophils

A type of white blood cell. Purpose: Help fight parasitic infections and participate in allergic reactions. Found: Blood and tissues.

Phagocytes

Immune cells such as neutrophils and macrophages. Purpose: Engulf and digest pathogens, foreign particles, and dead cells through phagocytosis. Found: Blood and body tissues.

Spleen

An organ containing immune cells and blood-filtering tissue. Purpose: Filters blood, removes old red blood cells, stores some platelets, and helps fight infections. Found: Upper left abdomen, behind the stomach.

Platelets

Small cell fragments formed from megakaryocytes in bone marrow. Purpose: Form platelet plugs and help blood clot. Found: Circulating in blood.

Hemostasis

The process of stopping bleeding. Includes vascular spasm, platelet plug formation, and coagulation. Purpose: Prevents excessive blood loss. Found: At the site of a damaged blood vessel.

Bone Marrow

Soft, spongy tissue inside bones. Purpose: Produces red blood cells, white blood cells, and platelets. Found: Inside bones, especially the pelvis, sternum, ribs, and vertebrae.

Hematopoiesis

The process of making new blood cells from hematopoietic stem cells. Purpose: Replaces old or damaged blood cells and maintains blood cell levels. Found: Primarily in red bone marrow in adults.

Cardiac Cycle

One complete heartbeat consisting of relaxation and contraction. Purpose: Pumps blood through the lungs and body. Main stages: Diastole (filling), atrial systole (atria contract), and ventricular systole (ventricles contract). Found: Heart.

SA Node (Sinoatrial Node)

Specialized cardiac muscle cells that start the electrical impulse and act as the heart's natural pacemaker. Found: Upper wall of the right atrium.

AV Node (Atrioventricular Node)

Specialized cardiac muscle cells that briefly delay the electrical impulse so ventricles can fill. Found: Lower right atrium near the septum.

Bundle of His (AV Bundle)

Specialized conducting cardiac muscle fibers that carry impulses from the AV node toward the ventricles. Found: Upper interventricular septum.

Bundle Branches

Specialized conducting fibers that carry electrical impulses down the right and left sides of the interventricular septum. Found: Interventricular septum.

Purkinje Fibers

Specialized cardiac conducting fibers that spread electrical impulses through the ventricular walls, causing contraction. Found: Walls of the ventricles.