Conceptual photocomposite of a healthy heart, showing a silhouetted man standing before a graph with a regular heartbeat pattern.

Illustration showing the concept of anorexia: a young woman seeing herself as fat.

Illustration showing the concept of anorexia: a young woman seeing herself as fat.

Photo illustration showing the concept of anorexia: a young woman seeing herself as fat.

Photo illustration showing the concept of anorexia: a young woman seeing herself as fat.

Illustration showing the concept of anorexia: a young woman seeing herself as fat.

Photo illustration of a sphygmomanometer with a hand squeezing the bulb to inflate the blood pressure cuff and a scale showing the normal blood pressure range.

Photo illustration of a sphygmomanometer with a hand squeezing the bulb to inflate the blood pressure cuff and a scale showing the normal blood pressure range.

Illustration of a man executing a flying kick in phase with his skeleton.

Illustration of a child running through space and time.

Illustration of a child running through space and time.

Illustration of a female figure looking straight ahead.

Illustration of a hand holding a glowing test tube, the concept of a scientific breakthrough.

Illustration of a hand holding a glowing test tube, the concept of a scientific breakthrough.

Photo illustration of an atom model pictured with laboratory glassware. Red spheres represent protons, blue spheres represent neutrons, and yellow spheres represent electrons.

Photo illustration of the inside of a human heart and a normal EKG on a flat screen computer monitor.

Photo illustration of the inside of a human heart and a normal EKG on a flat screen computer monitor.

Illustration of a woman sleepwalking through a dream.

Illustration of a woman sleepwalking through a dream.

Lyme disease cycle. Tick eggs become larvae and feed on small mammals or birds infected with the Lyme disease bacterium, Borrelia burgdorferi. Infected tick larvae then molt into nymphs, emerging aggressively in spring to infect new hosts, including humans. The nymphs molt to become adult ticks, which seek new hosts, mate, and produce eggs.