« previous next »
« previous next »
 

Did you know?

All adults should have their cholesterol levels checked once every 5 years. During 2009–2010, 69.4% of Americans age 20 and older reported having their cholesterol checked within the last five years.

Did you know?

Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.

Did you know?

Cyanide works by making the human body unable to use oxygen.

Did you know?

Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.

Did you know?

In 1844, Charles Goodyear obtained the first patent for a rubber condom.

The Structure of an Old High-Mass Star The Structure of an Old High-Mass Star
In some species, dominant females have more surviving offspring that mature earlier indicating an ad In some species, dominant females have more surviving offspring that mature earlier indicating an ad
The high-voltage shut-off switch on a Ford Escape hybrid. The switch is located under the carpet at ... The high-voltage shut-off switch on a Ford Escape hybrid. The switch is located under the carpet at ...
The pH scale is logarithmic. A low pH indicates acidic conditions, whereas a high pH indicates ... The pH scale is logarithmic. A low pH indicates acidic conditions, whereas a high pH indicates ...
Close-up of a flat-disc amplifier (left) and a bell amplifier (right) Close-up of a flat-disc amplifier (left) and a bell amplifier (right)
High school students shopping at the mall High school students shopping at the mall
Video: Phases of the ovarian cycle

For a complete list of videos, visit our video library