Tooth with cross-section of gum.

Pancreatic anatomy.

Fetal development.

Illustration of normal lungs.

Illustration of an adult's head and brain, showing the cerebral arteries.

Ovarian cysts.

Illustration of a developing fetus.

Anatomy of mouth and throat.

Illustration of the outline of a man, with his trachea, lungs, and heart visible.

Rod and cone retinal cells.

Illustration of the urinary system: kidneys, ureters, and urinary bladder.

Kidney glomerulus and renal tubules.

Renal artery disease.

Medical illustration highlighting sciatic nerve (yellow vertical line next to femur) and piriformis muscle (reddish line) connecting femur to pelvis.

Normal heart, anterior view.

Light rays passing through cornea, lens and focusing on retina.

Medical illustration showing normal bronchiole (left) versus bronchitis (right).

The brain: speech (red); complex, skilled movement (light blue); voluntary movement (dark blue); sensation (dark green); sensory interpretation (light green); speech interpretation (pink); visual interpretation (purple); vision (dark purple); hearing (yellow).

Illustration of the digestive system.

Human endocrine system showing major glands and related organs on female and male silhouettes.