Patella knee. These fractures usually cause swelling and pain in the region, bleeding into the joint (hemarthrosis), and an inability to extend the knee. Patella fractures are usually treated with surgery, unless the damage is minimal and the extensor mechanism is intact. An exostosis is the formation of new bone onto a bone, as a result of excess calcium formation. This can be the cause of chronic pain when formed on the patella. The patella is found in placental mammals and birds; most marsupials have only rudimentary, non-ossified patellae although a few species possess a bony patella. A patella is also
Composition of the human body are averages of different numbers reported by different references. The adult human body averages ~53% water. This varies substantially by age, sex, and adiposity. In a large sample of adults of all ages and both sexes, the figure for water fraction by weight was found to be 48 ±6% for females and 58 ±8% water for males. Water is ~11% hydrogen by mass but ~67% hydrogen by atomic percent, and these numbers along with the complementary % numbers for oxygen in water, are the largest contributors to overall mass and atomic composition figures. Because of water content, the human body