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Harrison, Ross Granville

(Encyclopedia)Harrison, Ross Granville, 1870–1959, American biologist and anatomist, b. Germantown, Pa., Ph.D. Johns Hopkins, 1894. He went to Yale as professor of comparative anatomy in 1907 and held various hon...

herpes zoster

(Encyclopedia)herpes zoster, infection of a ganglion (nerve center) with severe pain and a blisterlike eruption in the area of the nerve distribution, a condition called shingles. The causative organism is varicell...

sciatica

(Encyclopedia)sciatica sīătˈĭkə [key], severe pain in the leg along the sciatic nerve and its branches. It may be caused by injury or pressure to the base of the nerve in the lower back, or by metabolic, toxic...

neurotransmitter

(Encyclopedia)neurotransmitter, chemical that transmits information across the junction (synapse) that separates one nerve cell (neuron) from another nerve cell or a muscle. Neurotransmitters are stored in the nerv...

nervous system

(Encyclopedia)CE5 Nerve cell CE5 Nervous system nervous system, network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment. Virtually all members of ...

acetylcholine

(Encyclopedia)acetylcholine əsētˌəlkōˈlēn [key], a small organic molecule liberated at nerve endings as a neurotransmitter. It is particularly important in the stimulation of muscle tissue. The transmission ...

brain stem

(Encyclopedia)brain stem, lower part of the brain, adjoining and structurally continuous with the spinal cord. The upper segment of the human brain stem, the pons, contains nerve fibers that connect the two halves ...

synapse

(Encyclopedia)synapse sĭnˈăps [key], junction between various signal-transmitter cells, either between two neurons or between a neuron and a muscle or gland. A nerve impulse reaches the synapse through the axon,...

Hubel, David Hunter

(Encyclopedia)Hubel, David Hunter hyo͞oˈbəl [key], 1926–2013, American neurobiologist, b. Ontario, Canada, to American parents. In 1958, Hubel joined Torsten Wiesel at Johns Hopkins; the two relocated to Harva...

solar plexus

(Encyclopedia)solar plexus, dense cluster of nerve cells and supporting tissue, located behind the stomach in the region of the celiac artery just below the diaphragm. It is also known as the celiac plexus. Rich in...