References
15 March 2016, 04:33 PM ET
Numerous fossils make this one of the most-studied dinosaurs.
15 March 2016, 04:05 PM ET
Dinosaurs ruled the Earth for 135 million years. There were many types of dinosaurs, in all shapes and sizes.
14 March 2016, 05:35 PM ET
The large carnivorous dinosaur reigned during the late Cretaceous Period, 65 million years ago.
11 March 2016, 08:01 PM ET
The integumentary system consists of the skin, hair and nails.
11 March 2016, 07:49 PM ET
The urinary system — also known as the renal system — produces, stores and eliminates urine, the fluid waste excreted by the kidneys
11 March 2016, 07:43 PM ET
The lymphatic system helps rid the body of toxins.
11 March 2016, 07:35 PM ET
The 650 muscles in the human body control movement and help to maintain posture, circulate blood and move substances throughout the body.
11 March 2016, 06:54 PM ET
This may be the most important system in the body. Without the ability to reproduce, a species dies.
11 March 2016, 06:32 PM ET
The job of the immune system is to protect against disease.
11 March 2016, 06:20 PM ET
The endocrine system is a collection of glands that secrete hormones.
11 March 2016, 06:05 PM ET
The network of nerves is the body's electrical wiring.
11 March 2016, 05:55 PM ET
Good air in, bad air out.
11 March 2016, 05:37 PM ET
The human skeleton has 206 bones and performs several vital functions.
11 March 2016, 05:30 PM ET
The human circulatory system keeps blood, oxygen and nutrients flowing through the body.
11 March 2016, 05:15 PM ET
The human digestive system converts food into nutrients that the body needs.
11 March 2016, 01:06 AM ET
Vipers are found all over the world. This family of snakes include rattlesnakes, copperheads, adders and cottonmouths.
11 March 2016, 12:55 AM ET
Sepsis is the body's overreaction to infection. It can cause tissue damage, organ failure and death.
10 March 2016, 01:45 PM ET
Many complex processes go on inside the human body every day.
09 March 2016, 01:50 PM ET
A concussion is a traumatic brain injury (TBI) caused by the brain violently bouncing or twisting inside of the skull.
09 March 2016, 12:02 AM ET
Traumatic brain injury (TBI) is a very common brain condition marked by damage to the brain caused by an outside force.
07 March 2016, 03:25 PM ET
Multiple Sclerosis (MS) is a potentially incapacitating disease that poses unpredictable challenges, but does not signal a shorter lifespan.
02 March 2016, 06:18 PM ET
Kangaroos are marsupials native to Australia. Their babies are called joeys and they live in groups called mobs.
01 March 2016, 05:16 PM ET
Jaguars are large cats that can be found in North, Central and South America. They are identified by their yellow or orange coats, dark spots and short legs.
29 February 2016, 11:27 PM ET
Kingsnakes are medium-size nonvenomous snakes that kill by constriction. They are one of the most common snakes in North America.
29 February 2016, 11:14 PM ET
Electric current is electric charge in motion, such as the flow of electrons through a wire.
26 February 2016, 09:00 PM ET
Resistors, inductors and capacitors are basic electrical components that make modern electronics possible.
26 February 2016, 08:45 PM ET
Research has found that exposure to blue light suppresses the production of the sleep hormone melatonin more than any other type of light.
26 February 2016, 12:11 AM ET
Opioids are powerful painkillers but they can be dangerous with misuse.
25 February 2016, 11:56 PM ET
Rat snakes are medium-to-large, nonvenomous snakes that kill by constriction. Recent research has complicated the taxonomic classification of rat snakes.
24 February 2016, 10:19 PM ET
Mercury is a naturally occurring chemical, but it can become harmful when it enters the food chain.
22 February 2016, 07:56 PM ET
Human papillomavirus (HPV) infections are the most common sexually transmitted infection in the United States.
19 February 2016, 04:57 PM ET
Pythons are large constricting snakes native to Asia, Africa and Australia, although some have invaded Florida.