This document provides an overview of the 11 major organ systems in the human body. It describes the function and main components of each system, including the nervous, lymphatic, cardiovascular, respiratory, skeletal, muscular, digestive, excretory, and reproductive systems. The levels of organization in living things are also outlined, from atoms and molecules up to the whole organism. Homeostasis, the maintenance of internal stability, is introduced as an important involuntary process regulated by these organ systems.

1. BIOLOGY
Unit 7 Notes:
Living
Organization

2. (1) Living Organization
• All living things are made of cells and
atoms/molecules.
• Levels of Organization:
– Atoms and Molecules
– Organelles and Cells
– Tissues
– Organs
– Organ Systems
– Organism

4. (2) Homeostasis
• Involuntary processes and reactions are in place to
maintain Homeostasis within cells.
• Homeostasis = Internal stability / balance.

5. (3) Nervous System
• Function:
– Controls all other organ systems + homeostasis.
– Allows you to respond to changes/stimuli.
• Made Up Of:
– Brain
– Spinal Cord
– Nerves

7. (4) Lymphatic System
• (A.K.A. The Immune System)
• Function:
– Protect body against harmful infectious agents +
compounds.
• Made Up Of:
– White Blood Cells
– Lymph Vessels, Nodes, and Fluid

9. (5) Cardiovascular System
• Function:
– Work with the respiratory system to circulate gases.
– Pump nutrients throughout the body to working
tissues.
• Made Up Of:
– Heart
– Blood Vessels
– Blood + Blood Cells

11. (6) Respiratory System
• Function:
– Work with the cardiovascular system to circulate gases.
– Bring oxygen into body + expel carbon dioxide.
• Made Up Of:
– Nasal Cavity
– Lungs
– Diaphragm

13. (7) Skeletal System
• Function:
– Provide body support and mobility.
– Protect organs.
• Made Up Of:
– Bones
– Joints
– Cartilage

14. (8) Muscular System
• Function:
– Body + Organ mobility.
– Produce body heat.
• Made Up Of:
– Muscle
– Ligaments + Tendons

16. (9) Digestive System
• Function:
– Break food into smaller pieces.
– Metabolize biomolecules within food.
– Absorb useful nutrients + expel waste.
• Made Up Of:
– Oral Cavity + Esophagus
– Stomach
– Small + Large Intestine
– Rectum + Anus

17. (10) Excretory System
• (A.K.A. The Urinary System)
• Function:
– Filter Blood.
• Made Up Of:
– Kidneys
– Ureters
– Bladder
– Urethra

19. (11) Reproductive System
• Function:
– Pass genes on to produced offspring.
• Made Up Of:
– Male  Sperm, Testes, Penis
– Female  Eggs, Ovaries + Uterus, Vagina