Our body is composed of millions of cells. Our cells form unique cell types and function together to create biological machine. Our cells group together to form tissues which are specialized for different functions. Tissue can work together as an organ and supply the body with a particular function needed for survival. There are 10 different organ systems that make up the human body.
1. Muscular – The muscular system produces motion in body parts and our viscera (internal organs.)
2. Skeletal – Provides the structural support for the body, protection for internal organs, and generates all blood cells.
3. Circulatory / Immune System – Involved in the transport of nutrients, water, gases, hormones, blood, and cells; provides for protection from invading organisms.
4. Nervous – Allows the body to respond to both external and internal stimuli. Regulates and coordinates the body.
5. Integumentary – Prevents excess water loss and regulates the temperature
6. Digestive – Functions to break down food through release of enzymes to allow easy uptake of absorbable nutrients.
7. Respiratory – Allows for exchanges of gases.
8. Urinary – Removes bodily waste from bloodstream and regulates homeostasis.
9. Reproductive – Production of sex cells.
10. Endocrine – Regulates the growth of body via hormone secretion.
Not all ten organ systems are necessarily needed for a functioning human body. However each system was vital for human survival. Millions of years of evolution developed and finely tuned organ systems to increase our fitness.