|
|
Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.
Intradermal injections are somewhat difficult to correctly administer because the skin layers are so thin that it is easy to accidentally punch through to the deeper subcutaneous layer.
Adolescents often feel clumsy during puberty because during this time of development, their hands and feet grow faster than their arms and legs do. The body is therefore out of proportion. One out of five adolescents actually experiences growing pains during this period.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
![This 11-month old girl demonstrates one of the abilites of a child of this age group - creating a to](https://biology-forums.com/gallery/47/medium_2137_17_05_12_2_24_21.jpeg)
![Does this child have legs of different lengths or scoliosis? Look at the level of the iliac crests a](https://biology-forums.com/gallery/47/medium_14755_24_09_12_7_49_31_8985943.jpeg)