Neurite

Neurite is the term used to describe the cell extension of a nerve cell through which electrical impulses are transmitted to its environment. If the neurite is also surrounded by “glial cells” that isolate it, it is called an axon. Function and structure A neurite is the extension of a nerve cell, and directs its … Neurite

Dendrit

Definition Dendrites are the cytoplasmic extensions of a nerve cell, which usually branch off from the nerve cell body (soma) in a knot-like manner and become more and more finely branched in two parts. They serve to receive electrical stimuli from upstream nerve cells via synapses and transmit them to the soma. The dendrites also … Dendrit

Motor neuron

Motoneurons are the nerve cells responsible for the formation and coordination of movements. According to the location of the motoneurons, a distinction is made between the “upper motoneurons”, which are located in the cerebral cortex, and the “lower motoneurons”, which are located in the spinal cord. The lower motor neuron The lower motoneuron is located … Motor neuron

Nerve fiber

A nerve fiber is a portion of a nerve. A nerve is composed of several nerve fiber bundles. These nerve fiber bundles contain many nerve fibers. Each nerve fiber is surrounded by the so-called endoneurium, a kind of protective mantle around each nerve fiber. The endoneurium consists of connective tissue and elastic fibres and because … Nerve fiber

Action potential

Synonyms nerve impulse, excitation potential, spike, excitation wave, action potential, electrical excitation Definition The action potential is a short change of the membrane potential of a cell from its rest potential. It is used to transmit electrical excitation and is therefore elementary for the transmission of stimuli. Physiology To understand the action potential, one must … Action potential

Action potential at the heart | Action potential

Action potential at the heart The basis of electrical excitation of the heart is the so-called action potential. It represents the biologically temporally limited change of an electrical voltage across the cell membrane, which ends in a muscle action, in this case the heartbeat. With a duration of about 200 to 400 milliseconds depending on … Action potential at the heart | Action potential

Synaptic cleft

Definition The synaptic gap is a space between two communicating nerve cells that plays an important role in the transmission of action potentials (nerve impulses). In it a modulation of signal transmission takes place, which has a great pharmacological importance. Construction of a synaptic cleft A synapse is the transition between two nerve cells or … Synaptic cleft

Functionality of chemical synapses | Synaptic cleft

Functionality of chemical synapses Whenever a nerve cell sends a signal to a muscle, gland or other nerve cell, the transmission takes place via the synaptic gap, which is only about 20-30 nanometers wide. The long extensions of the nerve cells (also called “axons”) conduct the nerve impulse (i.e. the “action potential“) from the center … Functionality of chemical synapses | Synaptic cleft