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
A Ranvier lacing ring is a ring-shaped interruption of the fat or myelin sheath surrounding nerve fibers. In the course of “saltatoric excitation conduction” it serves to increase the speed of nerve conduction. Saltatoric, from Latin: saltare = to jump refers to the “jump” of an action potential that takes place when it encounters a … Ranvier lacing ring
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
Spinous processes Dendrites that do not have a spinous process are called “smooth” dendrites. They pick up nerve impulses directly. While the dendrites have the spines, the nerve impulses can be absorbed through the spines as well as through the dendrite trunk. The thorns emerge from the dendrites like little mushroom heads. They can increase … Spinous processes | Dendrit
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
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
Markless nerve fibers Markless nerve fibers can be found mainly where information does not have to be passed on so quickly. For example, pain nerve fibers that transmit information about pain sensation to the brain are partially markless. This is important because, for example, there is pain that has to last a long time. In … Markless nerve fibers | Nerve fiber
Nerve fiber quality Nerve fiber quality is used to describe from which part of the body information is passed on. On the one hand, there are the somatosensory nerve fibers, which are also called somatoafferent. Somato refers here to the body, sensitive or afferent, refers to the fact that the information is transmitted from the … Nerve fiber quality | Nerve fiber
Synonyms Cerebrospinal fluid Medical: Cerebrospinal fluid Definition The cerebrospinal fluid (liquor cerebrospinalis), also known as cerebrospinal fluid, is an endogenous fluid that is largely formed in the chambers (ventricles) of the brain by specialized vascular plexuses, the so-called plexus choroidei. It is formed by filtering the blood. The human body has about 100-150 ml of … Spinal fluid
Composition Normally the CSF/spinal fluid is clear and colorless, so that it resembles water in appearance. It contains very few cells, about 0-3 or 4 per μl. In the newborn, this number can be about twice as high. Mainly leukocytes are found in the cerebrospinal fluid, among them mainly lymphocytes, i.e. immune cells. Less frequently, … Composition | Spinal fluid
Increased cerebral pressure An increase in intracranial pressure may be congenital or acquired. The causes can also be different, either the drainage of the nerve water is disturbed or increased production occurs. Due to the excess of nerve water, there is not enough space in the so-called ventricles of the brain and the brain mass … Increased cerebral pressure | Spinal fluid
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