1 dic 2023 · Nerve, in anatomy, a glistening white cordlike bundle of fibers, surrounded by a sheath, that connects the nervous system with other parts of the body. The nerves conduct impulses toward or away from the central nervous mechanism. In humans 12 pairs are attached to the brain and 31 pairs to the spinal cord.
3 giorni fa · As an action potential (nerve impulse) travels down an axon there is a change in electric polarity across the membrane of the axon. In response to a signal from another neuron, sodium- (Na +) and potassium- (K +)–gated ion channels open and close as the membrane reaches its threshold potential.
21 nov 2023 · axon, portion of a nerve cell ( neuron) that carries nerve impulses away from the cell body. A neuron typically has one axon that connects it with other neurons or with muscle or gland cells. Some axons may be quite long, reaching, for example, from the spinal cord down to a toe.
7 dic 2023 · neuron, basic cell of the nervous system in vertebrates and most invertebrates from the level of the cnidarians (e.g., corals, jellyfish) upward. A typical neuron has a cell body containing a nucleus and two or more long fibres. Impulses are carried along one or more of these fibres, called dendrites, to the cell body; in higher nervous systems ...
27 nov 2023 · Summary. Peripheral nerve injuries result from systemic diseases (e.g., diabetes, autoimmune disease) or localized damage (e.g., trauma, compression, tumors) and manifest with neurological deficits distal to the level of the lesion. They occur as isolated neurological conditions or, more commonly, in association with soft tissue ...
23 nov 2023 · synapse, the site of transmission of electric nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell (effector). A synaptic connection between a neuron and a muscle cell is called a neuromuscular junction .
21 nov 2023 · Two studies show how messages can pass between cells over longer distances, through a ‘wireless’ nerve network in the worm Caenorhabditis elegans. Gigantic map of fly brain is a first for a ...