Cancer A tumor that is malignant, that is, it has the ability to metastasize or invade into surrounding tissues. Carbohydrates Organic compounds that serve as sources of energy for the body.  They are converted to glucose, which in turn is used by the cells in cell respiration. Carcinogenesis A general term for production of any type of tumor. Carcinoma A malignant tumor arising in epithelium.  It is the most common form of cancer and usually spreads via the lymphatic system. Cardiovascular System The organ system that transports oxygen and nutrients to tissues and removes waste products.  The main components are the heart, blood, and blood vessels. Cell Membrane A phospholipid bilayer which also contains cholesterol and proteins.  It functions to provide support and controls passage of all materials into or out of the cell. Cell The smallest living unit in the body. Cell Proliferation The process by which cells undergo mitosis and divide into similar cells. Cellular Swelling A pathologic condition of a cell that is associated with hypertrophy.  It is due to cellular hypoxia, which damages the sodium-potassium membrane pump.  This in turn changes the intracellular electrolyte balance causing an influx of fluids into the cell and resultant swelling. Central Nervous System (CNS) The part of the nervous system that consists of the brain and spinal cord. Centrioles Organelles composed of nine microtubule triplets that organize specific fibers of chromosomes and move the chromosomes during cell division.  There are two centrioles, aligned at right angles to each other. Cerebellum A posterior portion of the brain that is responsible for voluntary and involuntary motor activities based on memory and sensory input. Cerebrum The largest portion of the brain that controls thought processes, intelligence, memory, sensations, and complex motor functions. Chemicals Atoms or molecules that are the building blocks of all matter. Cilia Thread-like projections of the outer layer of the cell membrane, which serve to move substances over the cell, surface. Cirrhosis A specific condition of the liver in which the liver cells (hepatocytes) have been replaced by bands of fibrous tissue, which can not carry out the metabolic functions of the liver. CNS The part of the nervous system that consists of the brain and spinal cord. Connective Tissue One of the four tissues of the body.  It is specialized to provide support and hold the body tissues together (i.e., they connect). It contains more intercellular substances than the other tissues.  Bones, cartilage, and fat are types of connective tissue.  The blood and lymph vessels are immersed in the connective tissue media of the body. Cytoplasm A watery solution of minerals, organic molecules, and gases found between the cell membrane and nucleus. Cytosol The liquid part of the cytoplasm which distributes materials by diffusion throughout the cell.