01 October 2015, 11:44 PM ET
Turtles, tortoises and terrapins are reptiles with protective shells. They live on land, in the ocean and in lakes and rivers. There are more than 300 species.
30 September 2015, 11:01 AM ET
Inflammation is the body's response to injury. It works to heal wounds, but it can also play a role in some chronic diseases.
30 September 2015, 01:08 AM ET
Rats are thin-tailed, medium-size rodents that are found all over the world.
30 September 2015, 12:20 AM ET
The nose is part of the respiratory system and also contributes to other important functions, such as hearing and tasting.
24 September 2015, 11:48 PM ET
Moles are small tunneling mammals that live all over the world.
24 September 2015, 12:07 AM ET
The ears are complex systems that not only provide the ability to hear, but also make it possible to maintain balance.
23 September 2015, 09:17 PM ET
Lithium is a metal used in manufacturing, electronics and mental health.
21 September 2015, 07:35 PM ET
Lungs are an important part of the respiratory system. Adults take 15 to 20 breaths a minute, which comes to around 20,000 breaths a day.
19 September 2015, 08:38 AM ET
Into each life, some fall must reign.
17 September 2015, 12:27 AM ET
The bladder is a round, sack-like organ that stores urine. It is typically the size of a large grapefruit but can stretch much larger as needed.
08 September 2015, 04:10 PM ET
The history of computers starts with industrial and governmental needs, which led to huge machines and eventually the Internet, mobile phones and gaming systems.
03 September 2015, 10:19 PM ET
Cyclobenzaprine is a prescription medication that is used as a muscle relaxant. It is intended for short-term use, and should be used with other medications.
03 September 2015, 03:34 PM ET
Denali, formerly known as Mount McKinley, rises more than 20,000 feet above sea level.
01 September 2015, 02:27 AM ET
The small intestine is about as big around as a middle finger, but it is about 22 feet (6.7 meters) long.
01 September 2015, 02:21 AM ET
Kidneys are bean-shaped organs located on both sides of the spine, behind the stomach. Their main purpose is to keep the composition of blood in the body balanced to maintain good health.
01 September 2015, 02:14 AM ET
The stomach is a bean-shaped sack located behind the lower ribs. It is the first stop in the digestive tract before food moves on to the small intestine.
01 September 2015, 02:08 AM ET
The esophagus is a tube that connects the throat (pharynx) and the stomach. Within it, muscles contract to move food to the stomach.
28 August 2015, 11:58 PM ET
The large intestine, also called the colon, is part of the final stages of digestion. It is a large tube that escorts waste from the body.
27 August 2015, 12:47 PM ET
Thousands died and millions were left homeless in the most destructive storm to hit the United States.
27 August 2015, 01:02 AM ET
Dietary fiber is a plant-based nutrient that is sometimes called roughage or bulk. Fiber is important to digestion and regularity, weight management, blood sugar regulation, cholesterol maintenance and more.
26 August 2015, 04:11 PM ET
The human circulatory system keeps blood, oxygen and nutrients flowing through the body.
25 August 2015, 07:34 PM ET
Carbohydrates — one of the basic food groups — are the sugars, starches and fibers found in fruits, grains, vegetables and milk products. They are important to a healthy life.
25 August 2015, 07:21 PM ET
Vitamin A is good for healthy vision, skin, bones and other tissues in the body. Vitamin A often works as an antioxidant, fighting cell damage, but it also has many other uses.
25 August 2015, 12:32 AM ET
Riboflavin is a B-complex vitamin that helps the body break down carbohydrates, proteins and fats to produce energy.
24 August 2015, 09:37 PM ET
The human skeleton has 206 bones and performs several vital functions.
22 August 2015, 06:37 AM ET
Zofran: Dosage, Side Effects & Pregnancy
21 August 2015, 03:23 PM ET
The corpse flower is a pungent plant that blooms rarely and only for a short time. While it is in bloom, the flower emits a strong odor similar to rotting meat or, aptly, a decaying corpse.
20 August 2015, 09:39 PM ET
El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns.
20 August 2015, 02:28 AM ET
Vitamin B6 is important to maintaining a healthy body and developing a healthy brain.
18 August 2015, 07:32 PM ET
Vitamin K is known as the “blood-clotting vitamin” for its important role in healing wounds.
12 August 2015, 01:17 AM ET
Vitamin C, also called ascorbic acid, is important to many functions in the body. Many fruits and vegetables are good sources of vitamin C. Research is mixed on whether it really helps treat the common cold.
12 August 2015, 12:47 AM ET
Niacin is an essential vitamin that helps the digestive system, skin and nervous system to function.