1. Skin
![Skin © iStock Skin © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000072639415_Large-2d86972.jpg?webp=1&w=1200)
Average weight: 4,535g
Function: Protects against pathogens; provides insulation; synthesizes vitamin D; regulates temperature; provides sensation
2. Liver
![Liver © iStock Liver © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000070835515_Large-75d1ef0.jpg?webp=1&w=1200)
Average weight: 1,560g
Function: Breaks down toxins; produces hormones, proteins and digestive biochemicals; regulates glycogen storage
3. Brain
![Brain © iStock Brain © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000034826532_Large-f663c4d.jpg?webp=1&w=1200)
Average weight: 1,500g
Function: Drives executive functions such as reasoning; coordinates responses to changes in environment
4. Lungs
![Lung © iStock Lung © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000070835477_Large-e2b603a.jpg?webp=1&w=1200)
Average weight: 1,300g
Function: Supplies oxygen to be distributed around the body; expels carbon dioxide that is created around the body
5. Heart
![Heart © iStock Heart © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000016004558_Large-a5f8e54.jpg?webp=1&w=1200)
Average weight: 300g
Function: Pumps oxygenated blood from lungs around the body; pumps deoxygenated blood to the lungs
6. Kidneys
![Kidneys © iStock Kidneys © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000070835001_Large-133c21e.jpg?webp=1&w=1200)
Average weight: 260g (pair)
Function: Remove waste products; regulate sodium and water retention; filter blood; produce urine and hormones
7. Spleen
![Spleen © iStock Spleen © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000070836551_Large-87e12cb.jpg?webp=1&w=1200)
Average weight: 175g
Function: Filters blood; holds a reserve supply of blood; recycles iron; synthesizes antibodies; removes bacteria
8. Pancreas
![Pancreas © iStock Pancreas © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000015700703_Large-06adf31.jpg?webp=1&w=1200)
Average weight: 70g
Function: Produces insulin and glycogen; secretes enzymes that assist in the absorption of nutrients in the small intestine
9. Thyroid
![Thyroid © iStock Thyroid © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000035228418_Large-c7eec6d.jpg?webp=1&w=1200)
Average weight: 20g
Function: Controls body’s energy use; makes proteins; controls hormone sensitivity
10. Prostate gland
![Prostate gland © iStock Prostate gland © iStock](https://c02.purpledshub.com/uploads/sites/41/2018/07/iStock_000070834789_Large-1d4d825.jpg?webp=1&w=1200)
Average weight: 11g
Function: Secretes an alkaline fluid that constitutes 50-75 per cent of the volume of semen
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