17 Organs
The organ level of organization in the body may be the most familiar to us from our everyday experiences. Many of the common ailments we hear about—an upset stomach, a broken bone, lung disease, skin cancer—are named for the organs they affect.
An organ is made up of tissues that work together to perform a specific function for the body as a whole. Groups of organs that perform related functions are organized into organ systems, which perform more general functions. The table below describes the structures and functions of some common organs.
| Organ | Primary function(s) | Tissues it contains | Organ system(s) it is a part of |
|---|---|---|---|
| brain | control of body systems and behavior; cognition | nervous, connective, epithelial | nervous system; endocrine system |
| skin | protection; support and containment; temperature and fluid regulation | epithelial, nervous, connective, muscular | integumentary system |
| stomach | chemical and mechanical digestion of food | epithelial, connective, muscular, nervous | digestive system |
| sternum (breastbone) | support; protection; blood cell production | epithelial, connective, nervous | skeletal system; immune system; cardiovascular system |
| kidney | waste removal; fluid regulation | epithelial, connective, nervous | urinary system |
