Ganglion of the nervous system
anatomy
A ganglion of the nervous system is a collection of many nerve cell bodies in certain places in the body. The ganglion appears in the form of a thickening of the nerve cord. Depending on the position of the ganglion, it can be divided into different shapes.
If they are categorized according to body regions, one can find head ganglia, neck ganglia (cervical ganglia) or thoracic ganglia (thoracic ganglia). They can also be classified according to the different types of nervous systems found in the human body. There are two large groups, namely the so-called spinal ganglia and the autonomic ganglia.
The spinal ganglia belong to the so-called somatic nervous system on. This is also called the voluntary nervous system. It includes nerve fibers for that Motor skills, but also for them sensitivity. The spinal ganglia are found mainly in the area of the spine, shortly after the nerve fibers leave the spinal cord. Autonomous ganglia, on the other hand, as the name suggests, contain autonomic nerve fibers. These are not controllable at will. They contain so-called sympathetic and parasympathetic fibers (please refer: Sympathetic and Parasympathetic nervous system).
function
The function of the ganglia of the nervous system lies primarily in the Processing and forwarding of signals. The nerve nodes act as Control centers. Due to the accumulation of nerve cell bodies, information can be switched and linked from one nerve fiber to the next. In them, however, there is not just a pure switching of signals. Simple processing processes can also take place in the ganglia. The signals do not have to be passed on to the brain to be processed there. The signal processing can therefore take place relatively “close to the organs” and is therefore faster in terms of time. Some of the Reflexes in the body.
Ganglion oticum
The Ganglion oticum is a collection of cell bodies in the area of the skull base. It represents a so-called parasympathetic ganglion represent.
The ganglion thus contains autonomous nerve fibers. The ganglion oticum also contains other qualities of nerve fibers. There are both motor and sympathetic and parasympathetic nerve fibers. It functions as a switching station for some of the fibers. Above all, the parasympathetic fibers should be mentioned here. The other fiber qualities run through the ganglion without switching.
The nerve fibers that pass through the otic ganglion supply certain areas in the face, head and neck area. The motor fibers belong to the so-called Mandibular nerve and supply small muscles of the ear and muscles of the soft palate. They aid the hearing process and protect the inner ear from excessive volume. The innervated muscles of the soft palate support the process of swallowing. The parasympathetic fibers of the otic ganglion pull both to the Parotid gland (also called parotid gland) and the many small salivary glands in the cheek mucosa. There they lead to an increased secretion of saliva.
Stellate ganglion
The stellate ganglion also belongs to the autonomous nerve cell aggregations. In contrast to the otic ganglion, however, it contains sympathetic nerve fibers only. The stellate ganglion is located at the level of the lower cervical spine at the transition to the thoracic spine. The stellate ganglion arose from the fusion of two adjacent sympathetic nerve nodes, namely the lowest cervical ganglion and the uppermost thoracic ganglion.
Another term for the stellate ganglion is therefore also the cervicothoracic ganglion. As in the otic ganglion, some of the nerve fibers are connected directly in the ganglion, while other fibers simply pull through without switching. The stellate ganglion supplies various areas with its sympathetic nerve fibers. Here are above all the Innervation of the heart and lungs by calling sympathetic fibers. But also the thyroid and the Parathyroid are supplied by fibers from the stellate ganglion. The ganglion also gives off some sympathetic nerve fibers that supply certain areas of the head and neck.
What is also worth knowing about the stellate ganglion is that it is can switch off specifically. By a local anesthesia (see also: Local anesthesia) and a related blockage, one can reduce the effect of the sympathetic nervous system. The reduced effect leads to vasodilation in the corresponding area and to reduced sweat secretion. Also a so-called Horner syndrome can occur on the affected side. It is characterized by a drooping eyelid, a significantly narrowed pupil and an apparent sinking back of the eyeball into the eye socket.
For more information, see: Stellate ganglion
