| D008854 |
Microscopy, Electron |
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen. |
Electron Microscopy |
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| D009413 |
Nerve Fibers, Myelinated |
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves. |
A Fibers,B Fibers,Fiber, Myelinated Nerve,Fibers, Myelinated Nerve,Myelinated Nerve Fiber,Myelinated Nerve Fibers,Nerve Fiber, Myelinated |
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| D009435 |
Synaptic Transmission |
The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES. |
Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic |
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| D002540 |
Cerebral Cortex |
The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions. |
Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical |
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| D003712 |
Dendrites |
Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS. |
Dendrite |
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| D006801 |
Humans |
Members of the species Homo sapiens. |
Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man |
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| D000368 |
Aged |
A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available. |
Elderly |
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| D000375 |
Aging |
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time. |
Senescence,Aging, Biological,Biological Aging |
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| D001369 |
Axons |
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body. |
Axon |
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| D013569 |
Synapses |
Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions. |
Synapse |
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