Medical illustration of neurons and neuroglia, showing the basic design of nerve cells and myelinated nerve fibers. Labels identify the neuronal cell body, dendrites, axon, myelin, and glial cell bodies.

Medical illustration of neurons and neuroglia, showing the basic design of nerve cells and myelinated nerve fibers. Structures shown include the neuronal cell body, dendrites, axon, myelin, and glial cell bodies.

Medical illustration of the spinothalamic tract, labeled. The spinothalamic tract on each side carries pain and temperature information from the contralateral half of the body. Labeled structures include the cingulate gyrus, amygdala, hypothalamus, and the neospinothalamic, spinoreticular, paleospinothalamic, and spinomesencephalic tracts.

Medical illustration of the spinothalamic tract. The spinothalamic tract on each side carries pain and temperature information from the contralateral half of the body. Structures shown include the cingulate gyrus, amygdala, hypothalamus, and the neospinothalamic, spinoreticular, paleospinothalamic, and spinomesencephalic tracts.

Medical illustration of the brain and spinal cord illustrating the basic design of a tract, coronal section. Labeled structures include the brain, spinal cord, nucleus, and tract.

Medical illustration of the brain and spinal cord illustrating the basic design of a tract, coronal section. Structures shown include the brain, spinal cord, nucleus, and tract.

Medical illustration showing the human nervous system subdivided into the peripheral (left) and central (right) nervous systems, frontal view.

Medical illustration of dopamine pathways in the brain. The brain and spinal cord, lateral view, show the origin and distribution of dopamine. Labeled structures include the frontal and temporal lobes, midbrain, substantia nigra, ventral tegmental area, septal and diagonal band nuclei, amygdala, hippocampus, cerebellum, pons, medulla, and spinal cord.

Medical illustration of dopamine pathways in the brain. The brain and spinal cord, lateral view, show the origin and distribution of dopamine. Structures shown include the frontal and temporal lobes, midbrain, substantia nigra, ventral tegmental area, septal and diagonal band nuclei, amygdala, hippocampus, cerebellum, pons, medulla, and spinal cord.

Medical illustration of norepinephrine pathways in the brain. The brain and spinal cord, lateral view, show the origin and distribution of norepinephrine. Labeled structures include the frontal and temporal lobes, midbrain, locus ceruleus, hypothalamus, thalamus, septal and diagonal band nuclei, amygdala, hippocampus, cerebellum, pons, and medulla.

Medical illustration of norepinephrine pathways in the brain. The brain and spinal cord, lateral view, show the origin and distribution of norepinephrine. Structures shown include the frontal and temporal lobes, midbrain, locus ceruleus, hypothalamus, thalamus, septal and diagonal band nuclei, amygdala, hippocampus, cerebellum, pons, and medulla.

3D illustration of a typical hippocampal neuron, showing its connectivity and its multiple cell structures.

Medical illustration of Meissner's corpuscles (or tactile corpuscles), a type of mechanoreceptor responsible for sensitivity to light touch.

Medical illustration of Meissner's corpuscles (or tactile corpuscles), a type of mechanoreceptor responsible for sensitivity to light touch.

Medical illustration of the Pacinian corpuscle, an encapsulated receptor found in deep layers of the skin, that senses vibratory pressure and touch. Labels identify the sensory axon terminal, capsule, and myelinated axon.

Medical illustration of the Pacinian corpuscle, an encapsulated receptor found in deep layers of the skin, that senses vibratory pressure and touch. Shown are the sensory axon terminal, capsule, and myelinated axon.

Medical illustration showing the structure of a synapse with the presynaptic and postsynaptic neurons and oligodendroglia forming the myelin sheath. Labels identify structures including dendrites, axons, presynaptic and postsynaptic membranes, presynaptic and postsynaptic neurons, myelin, synapse, synaptic cleft, synaptic vesicle, and oligodendroglia.

Medical illustration of the structure of a synapse, with the presynaptic and postsynaptic neurons and oligodendroglia forming the myelin sheath. Structures shown include dendrites, axons, presynaptic and postsynaptic membranes, presynaptic and postsynaptic neurons, myelin, synapse, synaptic cleft, synaptic vesicle, and oligodendroglia.

Medical illustration of the major structures of the spinal cord, anterior view and cross section. Structures labeled include the anterior median fissure, spinal nerve, central gray columns, dorsal root ganglion, dorsal and ventral root filaments, funicular white matter, and ventrolateral, posterior median, and dorsolateral sulci.

Medical illustration of the major structures of the spinal cord, anterior view and cross section. Structures shown include the anterior median fissure, spinal nerve, central gray columns, dorsal root ganglion, dorsal and ventral root filaments, funicular white matter, and ventrolateral, posterior median, and dorsolateral sulci.