1. Organization and Homeostasis
Human Body
Organization and Homeostasis

2. Determined to be different
Cells do not begin their life as a heart, liver, skin, or stomach cell (etc.)
In the beginning, cells have the potential to become any of the 200 different cell types after going through the processes of determination and differentiation
After these processes the cell becomes specialized in a specific function, specialized cells are the first level of organization.
determination occurs within the first few weeks of zygote division where most stem cells become committed to develop into only one type of cell, still have the info just lose the ability to express it
Differentiation-committed cells acquire the structures and functions of highly specialized cells, occurs because specific genes are turned on

3. Cell Differentiation

4. Specialization
Each type of specialized cell has a particular structure to perform a specific task
The specialization of cells leads to the 11 major organ systems within your body

5. Levels of organization
28.1

7. Homeostasis
28.2
It is important for the systems in your body to maintain balance
The body can do so by sending feedback between systems
You have sensors in your skin, blood vessels, and of course the brain that allow signals to be sent and read to aid in processes such as thermoregulation

8. Feed back mechanisms Positive feedback Negative Feedback
a response that causes a change to continue in the same direction, does not result in homeostasis
Examples: childbirth, blood clotting
Negative Feedback
a response that reverses the change in order to restore homeostasis
Examples: thermoregulation, blood sugar regulation

9. Disrupting Homeostasis
28.3
Each system can affect the others through feedback
If drastic changes occur in one system such as
Failure to detect changes
Wrong messages sent
Serious injuries
Viruses or bacteria
Then what starts in one system can trigger a domino affect and cause both short and long term effects

11. Exit ticket
1) Name one fact you know about the human body.
2) What would you like to learn more about?