Resources and Glossary

Alveoli - Air cells of the lungs, formed by the terminal dilation of tiny air passageways.

Antibody - A protein that is made by certain white blood cells (lymphocytes), in the body, in response to foreign substance.

Aorta - The main trunk of the arterial system, carrying blood from the left ventricle of the heart to all of the lungs.

Arteries - Blood vessels that carry blood from the heart to any part of the body.

Bacteria - one-celled organisms, spherical, spiral, or rod-shaped and appearing singly, in chains, or in clusters.

Blood - The fluid that circulates in the principal vascular system of human being and other vertebrates: consisting of plasma in which the red blood cells, white blood cells, and platelets are suspended.

Bronchi - The main branches f the trachea.

Capillaries - The tiny blood vessels between the terminations of the arteries and the beginnings of the veins.

Chemotaxis - Movement of a cell toward of away from a chemical stimulus.

Cytoplasm - A jellylike material that surrounds the nucleus of a cell and contains most of the cell's organelles.

Differentiation - (of cells or tissues) to change from relatively generalized to specialized kinds, during development.

Erythrocyte - A red blood cell.

Fibrin - The insoluble protein end product of blood coagulation.

Germs - Any micro-organisms that cause disease.

Granulocyte - A circulating white blood cell having prominent granules in the cytoplasm and a nucleus lobes.

Hemoglobin - The oxygen-carrying protein of red blood cells that gives them their red color and serves to carry oxygen to the tissues.

Immunity - The condition that permits either natural or acquired resistance to disease.

Leukocyte - A white blood cell.

Lymphocyte - A type of white blood cell having a spherical nucleus surrounded by a thin layer of nongranular cytoplasm.

B Lymphocyte - A lymphocyte that is involved in the production of antibodies.

T Lymphocyte - A lymphocyte that helps in the priming of B lymphocytes to make antibody or is directly involved in attacking foreign cells, such as tumor cells.

Marrow - A soft, fatty, vascular tissue in the interior cavities of bones that is a major site of blood cell production.

Megakaryocyte - A large bone marrow cell having a lobulate nucleus (one with lobes); the source of blood platelets.

Mitosis - The usual method of cell division.

Monocyte - A large, circulating white blood cell, formed in bone marrow and in the spleen, that ingests large foreign particles and debris.

Nucleus - The part of the cell that holds genetic information as DNA.  Bacterial cells have no nucleus.

Nutrients - Substances that give sustenance to an organism.

Organelle - A specialized part of a cell having some specific function.

Phagocyte - Any cell that ingests and destroys foreign particles.

Phagocytosis - The ingestion of a smaller cell or fragment.

Plasma - The liquid part of blood or lymph, as distinguished from suspended elements.

Platelets - Small non-nucleated (having no nucleus) cells which form the first plug to stop bleeding.

Red Blood Cells - One of the cells of the blood, which form the first plug to stop bleeding.

Spleen - A highly vascular, glandular, ductless organ, situated in humans at the cardiac end of the stomach, serving chiefly in the formation of mature lymphocytes, in the destruction on worn-out red cells, and as a reservoir for blood.

Stem Cells - Cells that upon division replace their own numbers and give rise to cells that differentiate further into more specialized types, such as various B cells and T lymphocytes.

Transfusion - The direct transferring of blood, plasma, or the like into a blood vessel.

Veins - Branching vessels or tubes carrying blood from various parts of the body to the heart.

Vessel - A tube or duct such as an artery or vein, which contains or conveys blood or some other body fluid.

Virus - A tiny object that is composed of RNA or DNA and is surrounded by a protein cap or capsid.

White Blood Cells - Any of various nearly colorless cells of the immune system that circulate mainly in the blood an lymph.