1. Human Organ Systems

2. Circulatory System
Major Role in the Body: Transports oxygen, nutrients, and other needed materials to cells; transports wastes away from cells
Major Organs: Heart, blood vessels, blood

3. Digestive System
Major Role in the Body: Breaks down food into nutrients the body can use; disposes of solid wastes
Major Organs: Mouth (tongue, teeth, salivary glands), pharynx, esophagus, stomach, small intestine, large intestine, rectum, liver, pancreas, gall bladder

4. Endocrine System
Major Role in the Body: Secretes hormones to regulate body functions; coordinates other organ systems
Major Organs: Endocrine glands, pituitary, hypothalamus, pineal, thymus, thyroid, parathyroid, adrenals, pancreatic islets, testes (males), ovaries (females)

5. Immune system Major Role in the Body: Protects against disease
Major Organs: Lymph nodes, lymph vessels, white blood cells

6. Integumentary System
Major Role in the Body: Provides a barrier between the body and the external environment
Major Organs: Skin, hair, nails

7. Muscular System
Major Role in the Body: Moves the body; moves materials through the body
Major Organs: Skeletal muscles, tendons, smooth muscles

8. Nervous System
Major Role in the Body: Detects and responds to changes in the environment; transmits information as electrochemical impulses throughout the entire body
Major Organs: Brain, spinal cord, nerves

9. Reproductive System Major Role in the Body: Can produce offspring
Major Organs: Males: Testes, prostate gland, penis, vas deferens Females: ovaries, fallopian tubes, vagina, uterus

10. Respiratory System
Major Role in the Body: Exchanges oxygen and carbon dioxide between the body and the external environment
Major Organs: Nose, pharynx, larynx, trachea, bronchi, lungs

11. Skeletal System
Major Role in the Body: Moves and supports body; protects internal organs
Major Organs: Bones, cartilage, ligaments

12. Urinary System Major Role in the Body: Removes wastes
Major Organs: Kidneys, bladder, ureters, urethra