An asthma attack

Ovulation Animation

This animation shows the process of ovulation (the release a single egg cell from an ovary). Ovulation occurs though a sequence of hormonal responses. Located deep within the brain, the pituitary gland releases the hormones FSH and LH, which travel through the blood stream to the ovaries. These hormones signal the development and release a single egg cell from one of the ovaries. The sweeping motion of the fimbriae draws the egg cell through a very small space in the open body cavity into the uterine, or fallopian, tube. The egg cell will either be fertilized by sperm or will dissolve if fertilization does not take place.

• Women's Health

Diabetes mellitus - retinal conditions

This animation depicts changes to the retina resulting from diabetes mellitus.

• Diabetes
• Vision

Seated hamstring curl with weight machine

The seated hamstring curl with weight machine exercise targets the back of the thigh. See how it's done.

Ambien (zolpidem): Dosing and Common Side Effects

A brief discussion of Ambien dosing, dose limits, and common side effects

• Ambien

Cornea transplant

Video shows how full-thickness and partial-thickness cornea transplants are performed.