Overview Rash from poison ivy. Many people develop an itchy rash that causes lines or streaks that look like this. Poison ivy, oak and sumac: Overview Many people get a rash from poison ivy, poison oak, and poison sumac. This rash is caused by an oil found in the plants. This oil is called urushiol (you-ROO-shee-all).
Cells in heart muscle process a lot of energy, so they have a large number of mitochondrion, the part of the cells where energy is made. Like all living things, cells die. The number of cells that an adult male loses per minute is roughly 96 million.
An adult human, for example, has about 10 or even 100 trillion cells. The cell divisions are mitosis. By development we mean that as the embryo grows cells become different, a process that is called, logically enough, differentiation.