Artery		The process in which the lining of the uterus breaks up and is discharged from the body through the vagina
Capillary		Protection against a disease or condition; the person will not get or be affected by the disease
Cell		A group of cells with similar functions
Digestion		The substance in red blood cells that carries oxygen and gives blood its color
Hemoglobin		Organs that work together to perform special functions
Hormone		The burning of food for heat and energy by the cells
Immunity		The basic unit of body structure
Menstruation		The process of physically and chemically breaking down food so that it can be absorbed for use by the cells
Metabolism		A blood vessel that carries blood away from the heart
Organ		Groups of tissues with the same function
Peristalsis		A tiny blood vessel; food, oxygen, and other substances pass from the capillaries into the cells
Respiration		Involuntary muscle contractions in the digestive system that moves food down the esophagus through the alimentary canal
System		A chemical substance secreted by the endocrine glands into the bloodstream
Tissue		A blood vessel that returns blood to the heart
Vein		The process of supplying the cells with oxygen and removing carbon dioxide form them