Human Anatomy & Physiology Notes Chapter 1

Levels of Organization

1. Atoms

2. Molecules

3. Cells

4. Tissues

5. Organs

6. Organ System

7. Organism

Integumentary

Skin ( Covering) Skin is the largest organ

Skeletal

Supports and protects the body

Muscular

Support and movement

Nervous

Relays electrochemical messages from one body part to another

Endocrine

Control of body functions and message relaying ( Chemical signals = hormones)

Cardiovascular

Circulates blood

Lymphatic

Immune system

Respiratory

Oxygenates blood

Digestive

Digests food, absorbs nutrients

Urinary

Nitrogen waste is removed. Kidney = blood filter

Reproductive

Reproduction

Homeostasis

-Stable internal environment

- Body depends on it

- Requires the working together of all organ systems

Homeostatic Regulation

1. A stimulus goes to the receptor

2. The receptor sends a message to the control center

3. The control center sends a message to the effector

4. The effector causes another change to balance or increase the stimulus

Negative Feedback

A mechanism where the effective opposes or eliminates the stimulus ( Most Common)

Positive Feedback

Mechanism where the effector enhances the stimulus ( Ex. Blood clotting, childbirth)