1. Organization and Homeostasis
Animal Systems
Organization and Homeostasis

2. Organization in Living Things
Cells are organized into tissues
Tissues are organized into organs
Organs are organized into systems
Systems form an organism

4. Four tissue types
Epithelial
Connective
Nervous
Muscular

5. Epithelial tissue
Epithelial cells form the outer covering, line the internal cavities, and make up the glands.
Examples: Skin, mucous membranes.

7. Connective tissue Consists of living cells in a secreted matrix.
Examples: bone, cartilage, blood.

8. Muscular tissue
Specialized protein fibers allow these cells to contract.
Examples: skeletal muscle, smooth muscle, cardiac muscle.

9. Nervous tissue
Neurons have the ability to pass an “electrical” signal from one cell to another, or to target cells (muscles, glands, organs).

10. Tissues form organs
The skin is an example of an organ made up of multiple tissues: epithelial, muscular, nervous, and connective tissues.

11. Homeostasis
Homeostasis is the act of keeping the internal environment of a living organism within an acceptable range of conditions.
Homeostasis controls temperature, pH, blood volume, oxygen levels, blood sugar levels, and other conditions.
Negative feedback maintains homeostasis.

12. Negative Feedback
Negative feedback keeps conditions within an ideal range.
As conditions exceed the limits of the ideal range, chemical signals (hormones) regulate conditions. Most often this is controlled by the hypothalamus in the brain.

13. Positive Feedback
Positive feedback takes a condition out of the normal range, often to some end point.
During labor, oxytocin increases contractions, which stimulate more oxytocin production, until birth occurs.

14. Maintaining Temperature
Ectotherms are animals that derive body heat from the environment. Their body temperature may vary widely.
Endotherms rely on metabolic reactions and physiological systems to maintain a steady body temperature.

15. Maintaining Temperature

16. Blood Glucose Regulation