Mitral valve regurgitation

Heart and circulatory system

Watch this video to see how a healthy heart works.

Hamstring curl with resistance tubing

The hamstring curl with resistance tubing targets the back of the thigh. See how it's done.

Knee extension with weight machine

The knee extension exercise targets the front of the thigh. See how it's done.

Intracytoplasmic sperm injection

This animation shows the process of Intracytoplasmic sperm injection (ICSI), a procedure used to fertilize an egg cell outside of the body.

• Birth Control

Psoriasis

Animation of the skin layers and normal function of skin cells showing the immune response and what goes wrong in the skin cells causing psoriasis.