A chart compares the wing bones of a pterydon, bird, bat and human arm.

Illustration of the internal anatomy of the heart.

Illustration of the component layers of heart tissue.

Diagram showing the left ventricle of the heart.

Illustration of the respiratory system.

An illustration of the key component of the nervous system, the neuron. Neurons have a large number of extensions called dendrites; branches of the neuron cell body that can be long, or very short to act as chemical message receivers from other neurons. The main extension here is the axon, the purpose of which is to transmit electro-chemical signals from one neuron to another neuron. Long axons are covered by a myelin sheath, a fatty substance that covers the axon and insulates it. Shown here is the connection between one neuron (center) and a foreground neuron body. At the end of the axon ending, the bouton, a synapse with the dendrite of the foreground cell is taking place. Across this synapse, very small neurotransmitters (red) cross this gap into the next neuron, creating the nervous system message transferral system.

An illustration of the key component of the nervous system, the neuron; human brain in the background. Neurons have a large number of extensions called dendrites; branches of the neuron cell body that can be long, or very short to act as chemical message receivers from other neurons. The main extension here is the axon, the purpose of which is to transmit electro-chemical signals from one neuron to another neuron. Long axons are covered by a myelin sheath, a fatty substance that covers the axon and insulates it. Shown here is the connection between one neuron (center) and a foreground neuron body. At the end of the axon ending, the bouton, a synapse with the dendrite of the foreground cell is taking place. Across this synapse, very small neurotransmitters (red) cross this gap into the next neuron, creating the nervous system message transferral system.

Illustration depicting the human heart.

Illustration depicting a technique for treatment of vertebral compression fracture called balloon kyphoplasty. This minimally invasive treatment can relieve pain and improve quality of life in patients with these fractures.

This is an illustration of a vertebral compression fracture.

Illustration depicting the human heart.

Pancreas.

Pancreas.

Pancreas.

Human pancreas and gallbladder.

Human pancreas and gallbladder.

Human pancreas and gallbladder.

Human pancreas, gallbladder and stomach.

Human pancreas, gallbladder and stomach.

Human pancreas, gallbladder and stomach.