The respiratory system is responsible for taking in oxygen and expelling carbon dioxide. The main organs are the lungs, which work in concert with the cardiovascular system.
The heart, lungs and about 60,000 miles of blood vessels work together to keep blood pumping through our bodies.
Sometimes, at sunset, the sun appears to suddenly and briefly change color. Blink, and you'll miss it.
People who experience generalized anxiety disorder (GAD) exhibit excessive anxiety and worry about multiple events or activities most days of the week.
This may be the most important system in the body. Without the ability to reproduce, a species dies.
The urinary system — also known as the renal system — produces, stores and eliminates urine, the fluid waste excreted by the kidneys
The lymphatic system helps rid the body of toxins. Diseases of this system include lymphadenopathy, lymphoma and other disorders.
Chinese culture reflects the customs and traditions of one of the largest countries in the world, with 1.34 billion people.
Italian culture, steeped in the arts, architecture, music and food, has flourished for centuries. Here is a brief overview of Italian customs and traditions.
The history of computers starts with industrial and governmental needs, which led to huge machines and eventually the Internet, mobile phones and gaming systems.
India is one of the world's oldest and most diverse cultures. Here is an overview of Indian customs and traditions.
Culture is the characteristics of a particular group of people, defined by everything from language, religion, cuisine, social habits, music and arts.