1. The Human Body: An Orientation
Anatomy
The study of the structures or parts of the body.
Physiology
The study of the function of the body. (How the parts work.)

2. Anatomy – Levels of Study
Gross Anatomy
Large structures
Easily observable

3. Anatomy – Levels of Study
Microscopic Anatomy
Very small structures
Viewed with a microscope

4. Levels of Structural Organization
Atoms form molecules
Molecules form cells (the smallest units of living things)
A tissue consists of cells working together to perform a common function

5. Levels of Structural Organization
An organ consists of 2 or more tissues working together
An organ system is a group of organs working together
An organism consists of organ systems working together

6. Organ Systems Integumentary System
Forms the external body covering and protects the internal organs from infection.
Includes skin, hair and nails.

7. Organ Systems Skeletal System Functions in Movement and Support
Includes bones, cartilage, ligaments

8. Organ Systems Muscular System
Functions in movement of the body and through the body
Includes three types of muscles
Skeletal, cardiac and smooth (visceral)

9. Organ Systems Nervous System Fast acting control system
Also functions in communication
Includes brain, spinal cord and nerves

10. Organ Systems Endocrine System
Slower acting control system of the body
Glands secrete hormones to regulate the body

11. Organ Systems Cardiovascular System
Transports materials through the body via the bloodstream
Includes heart and blood vessels

12. Organ Systems Lymphatic System Returns tissue fluid to blood vessels
Important in immunity

13. Organ Systems Respiratory System
Supplies oxygen and removes carbon dioxide
Includes lungs, trachea, etc.

14. Organ Systems Digestive System
Digestion of food for absorption of nutrients
Includes stomach, intestines, etc

15. Organ Systems Urinary System Filters toxins from the blood
Includes kidneys, bladder, etc.

16. Organ Systems Reproductive Systems Produces offspring
Includes male and female genitalia

17. Homeostasis Maintenance of a stable internal environment
Temperature, fluid levels, pH, etc.
Must be maintained for normal functioning and to sustain life
Homeostatic imbalance – can result in disease or death

18. Maintaining Homeostasis
The body communicates through nervous and endocrine systems consisting of 3 basic components
1) Receptor
Detects a stimulus
2) Control center
Analyzes information
Determines appropriate response
3) Effector (Muscles or glands)
Responds to the stimulus

19. Maintaining Homeostasis
Metabolism – all chemical reactions within the body
Production of energy
Making body structures

21. Feedback Mechanisms Negative feedback
Includes most homeostatic control mechanisms
The response shuts itself off when it reaches the setpoint.
Example: Household thermostat

22. Feedback Mechanisms Positive feedback
Increases the intensity of the original stimulus until ultimate goal is reached
In the body, this only occurs in blood clotting and birth of a baby