How Body is Organized
Levels of Organization Cells Tissues Organs Organ Systems
Cells A cell is the basic unit of structure and function in a living thing. The cell membrane forms the outside boundary of the cell. Inside the cell membrane is a large structure called the nucleus.
Tissues A group of similar cells that perform the same function. The human body contains four basic types of tissue. Muscle Tissue-Contracts Nerve Tissue-Transmits Messages Connective Tissue-Support and Connects Epithelial Tissue-Lines Organs
Organs An organ is a structure that is composed of different kinds of tissue. The job of an organ is more complex than that of a tissue. The heart is an example and contains all four kinds of tissue.
Organ Systems Circulatory-Transports substances, fights disease Digestive-Breaks down food and absorbs materials. Endocrine-Controls body processes by chemicals (hormones) Excretory-Removes wastes Immune-Fights Disease Muscular-Enables the body to move Nervous-Detects & Interprets information Reproductive-Create Offspring Respiratory-Takes in O2 and eliminates CO2 Skeletal-Supports and Protects the Body. Allows Movement Skin-Keeps the water in the body/Regulates Body Temp.