The main systems of the human body are:

1. Circulatory system:

- Circulates blood around the body via the heart, arteries, and veins, delivering oxygen and nutrients to organs and cells and carrying their waste products away.

- Keeps the body's temperature in a safe range.

2. Digestive system and Excretory system:

- System to absorb nutrients and remove waste via the gastrointestinal tract, including the mouth, esophagus, stomach, and intestines.

- Eliminates waste from the body.

3. Endocrine system:

-Influences the function of the body using hormones.

4. Integumentary system/Exocrine system:

- Skin, hair, nails, sweat and other exocrine glands

5. Immune system and lymphatic system:

- Defends the body against pathogens that may harm the body.

- The system comprising a network of lymphatic vessels that carry a clear fluid called lymph.

6. Muscular system:

- Enables the body to move using muscles.

7. Nervous system:

- Collects and processes information from the senses via nerves and the brain and tells the muscles to contract to cause physical actions.

8. Renal system and Urinary system

- The system where the kidneys filter blood to produce urine and get rid of waste.

9. Reproductive system:

The reproductive organs required for the production of offspring.

10. Respiratory system:

- Brings air into and out of the lungs to absorb oxygen and remove carbon dioxide.

11. Skeletal system:

- Bones maintain the structure of the body and its organs.