Microbiology

Human beings as well as other multicellular organisms consist of many cells that work together to sustain life. Tissues are groups of cells that are similar in structure and work together to perform a specific function. There are four types of tissues: epithelial, connective, muscle and nervous. All types of tissues are distinct and their functions keep us as humans alive.

Epithelial tissue consists of sheet of cells that line and cover various parts of the human body such as your skin, mouth, bladder, blood vessels, etc. Epithelial tissues not only line parts of the body but it also serves as a protector to the underlying tissues. Its smooth structure also reduces friction which allows for fluids to flow over the tissues easily. Epithelial tissues are classified according to the cell shape. Squamous epithelium consists of one or more layers of flat cells. This type forms the outer surface of the skin as well as the inner surfaces blood vessels, lungs, mouth, vagina and throat. Cuboidal epithelium is a cubed shaped cell that forms kidney tubules and also covers the ovaries. Columnar epithelium consists of tall rectangular shaped cells that lines parts of the digestive tract, the larynx and several reproductive organs. Epithelial tissue is also classified by the number of layers they are in. A simple epithelium us a single layer of cells but a stratified epithelium consists of multiple layers.

Connective tissue supports the body against gravity and connects parts of the body together. Connective tissues have very few actual living cells. The tissue consists of nonliving extracellular material called the matrix. The material is produced by connective tissue cells and released into the open space between them. The matrix is the portion of the tissue that provides its strength. Connective tissue can be divided into two types: fibrous or specialized. Fibrous connective tissue connects various body parts together providing them with strength, support and...