Molecular model of methanol (also called carbinol or methyl alcohol), one of the congener compounds (along with ethanol) produced in alcohol fermentation. Congeners contribute to the flavor and color of alcoholic beverages and are believed to increase hangover symptoms.

3D CT scan of the head, showing the bones and vessels in an elderly man.

3D CT scan of the head, showing the bones and vessels in an elderly man.

3D CT scan of the head, showing the bones and vessels in an elderly man, side view.

3D CT scan of the head, showing the bones and vessels in an elderly man, side view.

3D CT scan of the head, showing the bones and vessels in an elderly man, side view.

3D CT of the head, showing the bones and vessels within the skull of an elderly man, top view. The top of the skull has been removed so that the observer can view the arteries at the base of the skull that supply the brain.

3D CT scan of the head, showing the bones and vessels in an elderly man.

3D CT scan of the head, showing the bones and vessels in an elderly man.

3D CT scan of the head, showing the bones and vessels in an elderly man.

3D CT scan of the head, showing the bones and vessels in an elderly man. There are some degenerative changes of the cervical spine.

Arthritis montage. An x-ray of osteoarthritic changes in the shoulder joint of an elderly male has superimposed over it three-dimensional molecular models of glucosamine and chondroitin sulfate, popular over-the-counter dietary supplements used to treat arthritis. Also shown is an illustration of a man hunched over with arthritic back pain.

3D illustration of the kidneys from a lateral oblique view. Also shown are the inferior vena cava, abdominal aorta, adrenal glands, and ureters.

3D illustration of a transparent kidney. The renal artery, ureter, calyxes, and medullary pyramids (renal pyramids) are also shown.

3D illustration of a kidney nephron, with the collecting tubule alongside it, forming the basic structural and functional unit of the kidney. The nephron includes the spherical renal corpuscle containing the glomerular (Bowman's) capsule, proximal and distal convoluted tubules, and the hairpin loop of Henle. It drains urine into the collecting tubule.

3D illustration of a kidney nephron, with the collecting tubule alongside it, forming the basic structural and functional unit of the kidney. The nephron includes the spherical renal corpuscle containing the glomerular (Bowman's) capsule, proximal and distal convoluted tubules, and the hairpin loop of Henle. It drains urine into the collecting tubule.

3D illustration of urolithiasis, the disease associated with the formation or presence of a calculus, or stone, in the urinary tract, here a kidney stone. The stone is shown in the ureter, inset.

Illustration of the lymphatic system in a male figure, frontal view.

3D medical illustration of lower back pain in a female figure, posterior oblique view.

3D medical illustration of lower back pain in a female figure, posterior oblique view.