Anatomical Terminology: An organism(an individual animal or plant) is made up of microscopic structures called cells,the basic structural units of living organisms. Some bacteria and parasitic microorganisms have only one cell. The human body, on the other hand, has trillions. Cells: Even microscopic cells vary in sizes. The human female’s ovum, or egg, is a single cell that’s hundreds of times bigger than a red blood cell. -Cells differ in shape; round and flat, thread shaped (trichoid), bricks, etc. The shape of a cell reflects on its specific function. Three main parts of a cell include; plasma membrane, cytoplasm and nucleus.
-Plasma membrane is the outer boundary of the cell. Holds strong and thin to allow substances in and out. Food and oxygen are beneficial and waste products are secreted. The movement of substances is called diffusion. Diffusion of water is called osmosis. ●Catabolism breaks down the metabolic phase; produces energy from food and oxygen. In the cytoplasm are structures called organelles, these cells perform vital functions. The nucleus is the cell's command and control center. It contains chromosomes of one or more nucleoli. A nucleolus is a rounded body that synthesizes cell protein. Chromosomes are structures containing a linear thread of DNA, the substance transmits genetic information and determines detailed appearance, structure and function. A maplike picture of the chromosomes within the nucleus is called a karyotype. Tissues: A tissue is a group or layer of similarly specialized cells that perform certain functions. Epithelial: This tissue is skin, but covers organs, lines body cavities and forms portions of ducts and glands. Also serves as protection of the body and absorbs, secretes and excretes substances. Muscle tissue: Three types of muscle tissue. Voluntary or striated muscle tissue is controlled by conscious effort, like the moving of an arm or leg. Striated means “streaked or scratched,” Involuntary or smooth muscle tissue works without conscious effort. It’s controlled by the nervous system and keeps automatic systems (like digestion) moving. Cardiac muscle tissue is a specialized form of involuntary muscle tissue found only in the