Illustration of a lymph node needle biopsy, showing the axillary (armpit) lymph nodes in a female patient, with a detail of the biopsy needle and tissue sample. This procedure is used to diagnose lymphoma and the spread of cancer.

Illustration of a needle biopsy, showing the axillary (armpit) lymph nodes in a female patient, with a detail of the biopsy needle and tissue sample. This procedure is used to diagnose lymphoma and the spread of cancer.

Illustration of the thoracic lymph nodes and the lungs, showing lung cancer and lymph nodes affected by the tumor. Labeled lymph nodes include the supraclavicular, contralateral, ipsilateral, mediastinal, and hylar lymph nodes.

Illustration of a neuron being stimulated by an electrode in a culture and the rise of calcium (Ca+).

Illustration showing common hematomas (hemorrhagic disorders) of the head.

Illustration showing an algorithmic organization of the central nervous system.

Illustration of the cervical vertebrae afflicted with spondylosis, anterolateral view. Spondylosis is a degenerative disease that leads to stiffening and ankylosing (bone fusion) of the vertebrae.

Illustration of a continuous suture pattern.

Medical illustration of the contraction of intrafusal muscle fibers. Shown are gamma (fusimotor) fiber, group Ia afferent fiber, and nuclear bag intrafusal fiber.

Medical illustration depicting sudden infant death syndrome (SIDS). There is uncertainty about the possible causes of SIDS, but an inadequate amount of oxygen in the blood may cause conditions including alterations of respiratory control, cardiac rhythm, and brain activity, followed by hyperventilation and tissue hypoxia, leading to sudden death.

Medical illustration of traumatic injuries to the chest, abdomen, and pelvic cavity. Guns, knives, and accidents can cause numerous injuries to internal organs. Shown here are lacerated, punctured, and transected organs, and fractured and separated ribs.

Medical illustration of the organs involved in traumatic shock, which involves organs and systems in a cascade of events that can lead to unconciousness and death. These events can include hemorrhage, blood pooling, and a drop in blood pressure.

Medical illustration of primary and secondary head trauma injuries. Primary head injuries (lacerations, contusions, and fractures) can be accompanied by swelling and hemorrhage, leading to loss of conciousness, low blood pressure, and shock.

Illustration of the apparatus used in trauma management. The patient is immobilized on a spine board with a cervical collar, blood pressure cuff, shock trousers, and arm bandage. Also shown are an accessory resuscitation breathing apparatus (left) and a venturi oxygen breathing mask (right).

Special effects of a red human heart showing arteries on a black background and a star on the surface.

Computer graphics showing blood cells flowing through a blood vessel.

Computer graphics of EKG superimposed on heart.

Cocaine, razor, money and straw with man's face in the background, a symbolic illustration of addiction.

Symbolic illustration of alcohol abuse.

Implant of fetal tissue in brain with Parkinson's disease. Parkinson's disease is a condition linked to a deficiency of the brain chemical, dopamine. Studies have shown that implanting fetal tissue relieves Parkinson's tremors and rigidity.