Med Term Cells terms & defintions (pt. 1 body organization)

Cell terms from textbook

Cell

Basic unit of all living things. The human body is composed of trillions of cells, which vary in size and shape according to function.

Cell Membrane

Froms the boundary of the cell.

Cytoplasm

Gel-like fluid inside the cell

Nucleus

Largest structure within the cell, usually spherical and centrally located. It contains chromosomes for cellular reproduction and is the control center for cellular activity.

Chromosomes

threadlike structures located in the nucleus of the cell. There are 46 chromosomes in all normal human cells, with the exception of mature sex cells, which have 23.

Genes

Regions within the chromosome containing sequences of DNA. Each chromosome has several thousand genes that determine hereditary characteristics.

DNA

long, complex molecule containing genetic material that regulates the activities of the cell. DNA is the abbreviation for deoxyribonucleic acid.

Tissue

group of similar cells that performs a specific function

Muscle tissue

group of similar cells that has a special ability to contract, usually producing movement

Nerve tissue

group of similar cells that receives and transmits electrochemical signals; found in the nerves, spinal cord, and brain. It is responsible for coordinating and controlling body activities.

Connective tissue

group of similar cells that attaches, supports, penetrates, and encases various body structures. Adipose (fat), osseous (bone) tissues, and blood are types of connective tissue. Fibrous tissue is a type of connective tissue that provides strength and stability, such as in ligaments and tendons.

Epithelial tissue

group of similar cells that covers the external surface of the body, forms membranes that line body cavities and organs, and is the primary tissue in glands. Glandular tissue is designed to secrete substances such as digestive enzymes.

Organ

two or more types of tissues that together perform special body functions. For example, the skin is an organ composed of epithelial, connective, muscle, and nervous tissue.

Viscera

large internal organs contained in the body cavities, especially in the abdominal cavity

System

group of organs that works together to perform complex body functions. For example, the cardiovascular system consists of the heart, blood vessels, and blood. Its function is to transport nutrients and oxygen to the cells and remove carbon dioxide and other waste products