The autonomic nervous system

The autonomic nervous system, also called autonomous (systema nervosum autonomicum), controls vegetative functions of the body - such as eating, breathing, circulation of fluids, selection, reproduction. It mainly supplies the internal organs and consists of two main divisions: the sympathetic and parasympathetic. The joint work of both departments is regulated and controlled by the cerebral cortex, which is the highest department of the central nervous system. Centers of the autonomic nervous system located in the brain and spinal cord. Allocate as a peripheral part, which are the nerves, the nerves, plexus and components.

Centers sympathetic division (pars sympathica) are in the lateral horns of gray matter in the thoracic and lumbar spinal cord. In the anterior roots of spinal cord are preganglionic sympathetic fibers coming from the centers to prespinal and paravertebral sympathetic nodes department. Paravertebral nodes (ganglia trunci sympathici) extend along the entire spine, from the level of the skull base to the top of an oil bones, and connect with each other Cross-Site branches (rr. interganglionares), forming two sympathetic trunk (truncus sympathicus) - Left and right. Depending on the location of nodes in each of the sympathetic trunk have identified a number of departments.

Cervical sympathetic trunk (pars cervicalis trunci sympathici) includes an upper, middle and lower units, which are located on both sides of the spine. Postganglionic fibers coming from the nodes, directed along the arterial branches of the head, neck and chest and form a plexus. Postganglionic fibers also from each node are part of the upper, middle and lower sympathetic nerves which go to the heart and with parasympathetic and somatic nerves form the cardiac plexus.

Thoracic sympathetic trunk (pars thoracica trunci sympathici) formed 10.12 sympathetic nodes irregularly triangular in shape, located near the heads of the ribs. 1-5-th nodes give postganglionic fibers bound to the thoracic aorta and forming around the sympathetic plexus. From this plexus, following the branches of the thoracic aorta to the esophagus, bronchi and lungs are sent to separate plexus. Postganglionic fibers of the 6-9th units join together to form large splanchnic nerve (n. splanchnicus major). Fiber 10-12th nodes form a small splanchnic nerve (n. splanchnicus minor). Splanchnic nerve through a slit aperture penetrating into the abdominal cavity and are involved in the formation of the celiac plexus.

Abdominal, or lumbar, Department of the sympathetic trunk (pars abdominalis trunci sympathici) consists of the lumbar sympathetic ganglia, arranged four on each side. They lie on the anterior surface of bodies of lumbar vertebrae and are connected by transverse and longitudinal branches of the Cross-Site. Postganglionic fibers of the two upper lumbar nodes are involved in the formation of the celiac or solar, plexus (plexus coeliacus). In addition to these fibers in the solar plexus are splanchnic nerves, postganglionic fibers of 1-2nd lumbar sympathetic ganglia, and parasympathetic fibers nucleus of the vagus nerve. From the solar plexus along the branches of celiac and superior mesenteric arteries of the same name directed plexus that innervate the pancreas and intestine to the descending colon. A pair of branches along the abdominal artery plexus sent to the kidneys, adrenal glands and gonads.

Postganglionic fibers of the lumbar sympathetic ganglia form a plexus of the abdominal aorta (plexus aorticus abdominalis), from which the fibers diverge along the branches of inferior mesenteric artery and innervated organs, supplied it with blood. Plexus of the abdominal aorta divides into two iliac plexus (plexus iliacus) - left and right. Iliac plexus innervate the lower extremities, and abdominal aortic plexus goes to the upper hypogastric plexus (plexus hypogastricus superior). In the sacral promontory upper hypogastric plexus, in turn, splits into two lower hypogastric plexus (plexus hypogastricus inferior), which are sent along the branches of the internal hypogastric artery and innervate the pelvic organs.

Pelvic, or sacral, Department of the sympathetic trunk (pars pelvina trunci sympathici) formed four pairs of sacral sympathetic ganglia, which are located on the anterior surface of the sacrum, and interconnected by transverse and longitudinal branches of the Cross-Site. In this case the lower sacral nodes are connected with an unpaired coccygeal junction. In the pelvic postganglionic fibers of sacral sympathetic ganglia combined with the lower hypogastric plexus.

Parasympathetic centers (pars parasympathica) form two parts: the cranial, located in the brain and cerebrospinal occurring in the spinal cord.

Cranial part consists of several departments.

Department mesencephalic parasympathetic system provides an additional nucleus of the oculomotor nerve (nucleus accessorius), the so-called core Yakubovich. It is located in the midbrain and is the beginning of preganglionic fibers, which are involved in the formation of ciliary angle (ganglion ciliare). Site of the ciliary fibers to the ciliary muscle followed and muscle, which narrows the pupil.

Bulbar department parasympathetic system, which is also called a diamond-shaped, formed the upper salivary nucleus, lower salivary nucleus and posterior nucleus of the vagus nerve.

Superior salivary nucleus (nucleus salivatorius superior) is located in the lid of the bridge. The fibers of the cells form an intermediate nerve (n. intermedius), which is part of the facial nerve (n. facislis), and then gives the two branches of preganglionic fibers: a drum and a large string of rocky nerve. Preganglionic fibers the tympanic string (chorda tympani) are sent to the submandibular node (ganglion submandibulare), and from him already postganglionic fibers - to the submandibular and sublingual salivary glands. Preganglionic fibers of a large rocky nerve (n. petrosus major) are sent to the pterygopalatine node (ganglion pterygopalatinum), from which postganglionic fibers to the mucosa followed by palate and nasal cavity.

Lower salivary nucleus (nucleus salivatorius inferior) is located in the medulla oblongata. Its preganglionic fibers are part of the glossopharyngeal nerve (n. glossopharyngeus) and in the drum of the nerve (n. tympanicus), which is a branch of the glossopharyngeal and penetrate into the tympanic cavity, forming the tympanic plexus. Then follow the fibers in the form of small rocky nerve (n. petrosus minor), leaving the tympanic cavity and reach the ear node (ganglion ocitum). From the ear node postganglionic fibers are part of ushno-temporal nerve (n. auriculotemporalis) and sent to the parotid gland.

Rear nucleus of the vagus nerve (nucleus dorsalis n. vagi) is also located in the medulla oblongata. Its preganglionic fibers together with his own somatic fibers are sent to the organs in the head, neck, chest and abdominal cavity, forming a plexus, and end at predorgannyh, and in-wall okoloorgannyh nodes: the nodes of laryngeal, pharyngeal, cardiac, pulmonary plexus, and plexus of the gastrointestinal tract. Postganglionic parasympathetic fibers to follow the smooth muscle wall of the internal organs and glands, resulting in effectors.

Sacral parasympathetic division of the system contains an intermediate-lateral nucleus of the lateral horn of the spinal cord II-V sacral segments. One group of processes of its cells - preganglionic fibers - comes from the brain in the anterior roots, below the lower hypogastric plexus and ends at the end nodes. Postganglionic fibers form a plexus, whose branches are sent to the organs of the pelvis. Another part of the preganglionic fibers is directed upwards, reaching the upper hypogastric plexus, inferior mesenteric plexus and the plexus of the abdominal aorta, with branches from the lower mesenteric artery should be to the authorities, supplied it with blood.

List of Abbreviations

a., aa. — arteria, arteriae (artery, the artery)

lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)

m., mm. — musculus, musculi (muscle, the muscle)

n., nn. — nervus, nervi (nerve, the nerve)

r., rr. — ramus, rami (branch)

s. — seu (or)

v., vv. — vena, venae (vienna)