Human Anatomy - Kotsan I. Ya. 2009

Autonomic Nervous System
Autonomic plexuses of the thoracic and abdominal cavities

In the thoracic cavity, major Autonomic plexuses are located along the descending aorta, in the region of The Heart, the pulmonary hila, and around the Esophagus.

1. The thoracic aortic plexus (plexus aorticus thoracicus) lies on the wall of the Thoracic Aorta and is formed by branches from the five upper thoracic ganglia of the Sympathetic trunk, Branches of the greater splanchnic nerve, and sensory fibers of the Vagus nerve. This plexus contains both sympathetic and parasympathetic nerve fibers. Branches of the thoracic aortic plexus extend along the Branches of the thoracic aorta.

2. The cardiac plexus (plexus cardiacus) is an extra-organ nerve plexus of the heart. It is formed by sympathetic and parasympathetic nerves. The sympathetic nerve branches originate from the three cervical and four to five upper thoracic sympathetic ganglia: the superior, middle, and inferior cervical cardiac nerves. Parasympathetic cardiac branches separate from the vagus nerve. These include the superior cardiac branches, which arise from the cervical portion of the vagus nerve, and the inferior cardiac branches, arising from the recurrent laryngeal nerve (a branch of the vagus nerve). These branches form two cardiac nerve plexuses: the superficial cardiac plexus (plexus cardiacus superficialis) and the deep cardiac plexus (plexus cardiacus profundus). The former is situated between the aortic arch and the bifurcation of the pulmonary trunk, while the latter is more prominent and located between the aortic arch and the bifurcation of the Trachea.

Branches of the cardiac plexuses accompany the arterial Vessels of the heart down to their terminal ramifications. The cardiac nerves and plexuses contain sympathetic, parasympathetic, and afferent fibers. Numerous sympathetic and parasympathetic Nerve Cells and small ganglia are found within the cardiac plexuses.

3. The pulmonary plexus (plexus pulmonalis) is located in the region of the roots of the Lungs. It is formed by mediastinal branches from the five upper thoracic sympathetic ganglia, as well as 5–6 branches originating from the thoracic part of the vagus nerves just dorsal to the main Bronchi. The ganglia of the pulmonary plexus contain A large number of sympathetic and parasympathetic nerve cells and small ganglia. From the pulmonary plexus, nerves extend along the vessels and bronchi into the lobes, segments, and lobules. Within the bronchovascular bundles, the pulmonary nerves form plexuses containing small nerve ganglia.

4. The esophageal plexus (plexus oesophagealis) surrounds the wall of the esophagus and is formed by esophageal branches of the thoracic sympathetic trunk and branches of the anterior and posterior vagal trunks.

The Abdominal cavity contains the largest number of autonomic plexuses and ganglia. Topographically, the following main plexuses are distinguished.

1. The celiac plexus, or solar plexus (plexus coeliacus seu plexus solaris), is one of the largest autonomic plexuses (sometimes referred to as the abdominal Brain). It is shaped like a horseshoe or ring around the celiac trunk at the level of the twelfth thoracic vertebra. Its superior parts are connected with the thoracic aortic plexus, and its inferior parts with the superior mesenteric plexus.

The greater and lesser splanchnic nerves, the vagus nerve, the lumbar (right and left) ganglia of the sympathetic trunk, the thoracic aortic plexus, and the phrenic nerve all send branches to the celiac plexus.

Among the ganglia of the celiac plexus, the largest are typically the celiac ganglia (ganglia coeliaca) and the aortorenal ganglia (ganglia aortorenalia). The celiac ganglia (right and left) are located on either side of the Base of the celiac trunk, whereas the aortorenal ganglia (right and left) lie near the Water/144.html">Origin of the renal artery from the aorta.

These ganglia are interconnected by nerve branches, which also harbor small clusters of nerve Cell bodies belonging to the second neuron chain of the sympathetic Nervous system. Postganglionic sympathetic and preganglionic parasympathetic fibers emerge from the ganglia to participate in The formation of periarterial (vascular) and organ plexuses. Among them, the following can be distinguished:

a) the hepatic plexus (plexus hepaticus), which extends from the celiac plexus to the porta hepatis, surrounding the hepatic Arteries; it is formed by fibers from the celiac plexus and the anterior vagal trunk;

b) the splenic plexus (plexus lienalis), which accompanies the splenic artery to the hilum of the Spleen; it is formed by branches of the celiac plexus and the common posterior trunk of both vagus nerves;

c) the gastric plexuses (plexus gastrici), which extend from the celiac plexus to The Stomach, surrounding the left gastric artery. They are formed by branches of the celiac plexus and the anterior vagal trunk. Branches of the gastric plexuses supply the anterior and posterior walls of the stomach, accompanying arterial ramifications;

d) the pancreatic plexus (plexus pancreaticus), formed by branches of the celiac, hepatic, superior mesenteric, and splenic plexuses, as well as branches of the left renal plexus;

e) the suprarenal plexus (plexus suprarenalis), which is paired and consists of 20–30 fine nerve branches that pass from the celiac plexus into the substance of the Adrenal gland from its posterior aspect;

f) the phrenic plexus (plexus phrenicus), which is paired and represents a continuation of interwoven branches of the celiac plexus running along the inferior phrenic artery.

2. The superior mesenteric plexus (plexus mesentericus superior) is closely linked to the celiac plexus and appears as its direct continuation. Topographically, it is located at THE ORIGIN OF the superior mesenteric artery at the level of the first lumbar vertebra and extends along the course of the corresponding artery to its terminal branches. The superior mesenteric plexus is formed by preganglionic fibers of the splanchnic nerves, which either bypass the celiac ganglia or pass in transit through their substance to reach the Neurons of the superior mesenteric plexus ganglia. Additionally, postganglionic sympathetic and afferent nerve fibers run within the superior mesenteric plexus. The latter form receptor endings in the abdominal Organs, primarily in the intestinal wall. The Formation of the superior mesenteric plexus also involves the posterior vagal trunk and the Visceral branches of the upper four lumbar sympathetic ganglia. It includes the large superior mesenteric ganglion (ganglion mesentericum superius) as well as smaller ganglia of varying size, shape, and Location. The superior mesenteric plexus innervates the abdominal organs supplied by branches of the artery of the same name (the Pancreas, Small Intestine, and Large Intestine up to the left colic flexure).

3. The abdominal aortic plexus (plexus aorticus abdominalis) is a direct continuation of the celiac and superior mesenteric plexuses, extending as a neural-fibrous sheet along the ventral surface of the aorta from the superior to the inferior mesenteric arteries. Its formation involves afferent and efferent fibers of the greater and lesser splanchnic nerves that pass in transit through the celiac and superior mesenteric plexuses. Nerve branches of the abdominal aortic plexus also contain postganglionic fibers, which are processes of cells from the nerve ganglia of the sympathetic trunk, as well as the celiac and superior mesenteric plexuses.

The abdominal aortic plexus gives off branches to the renal plexus (plexus renalis), which is paired and situated along the renal artery and its branches. The renal plexus is formed by branches of the celiac and superior mesenteric plexuses, visceral branches of the upper lumbar sympathetic ganglia, and ascending nerve trunks from the inferior mesenteric plexus, superior hypogastric plexus, and hypogastric nerves.

Branches of the abdominal aortic plexus form the plexuses of the gonadal arteries: the testicular plexus (plexus testicularis) in males, and the ovarian plexus (plexus ovaricus) in females.

4. The inferior mesenteric plexus (plexus mesentericus inferior) arises from the abdominal aortic plexus. It extends along the inferior mesenteric artery and its branches, forming corresponding plexuses around them. The inferior mesenteric plexus is formed by branches of the celiac and superior mesenteric plexuses that enter it via the intermesenteric plexus (a neural-fibrous cord connecting the superior and inferior mesenteric plexuses). Nerve branches from the upper lumbar sympathetic ganglia also contribute to the inferior mesenteric plexus. The inferior mesenteric plexus innervates the transverse and descending colon, the sigmoid colon, and the upper rectum. Near the origin of the inferior mesenteric plexus lies the inferior mesenteric ganglion (ganglion mesentericum inferius), the postganglionic fibers of which travel into The Pelvis as part of the hypogastric nerve.

5. The superior hypogastric plexus (plexus hypogastricus superior) is unpaired and located just below the aortic bifurcation. It is formed by branches of the abdominal aortic plexus, the lower lumbar ganglia, and the first sacral ganglion of the sympathetic trunk. The lower part of the superior hypogastric plexus, situated below the sacral promontory, divides into two nerve bundles—the right and left hypogastric nerves (n. hypogastricus dexter/sinister)—which run inferiorly and laterally, connecting the superior hypogastric plexus with the inferior one. Ascending from the hypogastric nerves are nerve fibers that enter the mesocolon of the sigmoid and descending colon, the superior rectal plexus, the inferior mesenteric plexus, and occasionally the renal plexus. Furthermore, branches from the hypogastric nerves supply the sigmoid colon and rectum, the lower part of the Ureter, and the Urinary Bladder, alongside branches that contribute to forming plexuses around the arterial vessels of the lesser pelvis.

6. The inferior hypogastric plexus (plexus hypogastricus inferior), or pelvic plexus (plexus pelvicus), is paired and located anteriorly and laterally to the rectum On the surface of the levator ani Muscle. It is one of the largest autonomic plexuses. Incorporating elements of both the sympathetic and parasympathetic nervous systems, it is formed by sympathetic fibers from the hypogastric nerves and sacral splanchnic nerves, as well as parasympathetic fibers from the pelvic splanchnic nerves. The ganglia of the inferior hypogastric plexus vary in size and shape, and their topography within the plexus is highly variable. In addition to ganglia, the nerve bundles of the plexus contain a large number of scattered neurocytes.

Through its branches, the inferior hypogastric plexus participates in forming A number of secondary plexuses, named after the organs they innervate:

a) middle rectal plexus (plexus rectalis medius) is located on the wall of the middle part of the rectum and is formed by branches of the inferior hypogastric and superior rectal plexuses;

б) нижнє прямокишкове сплетення (plexus rectalis inferior) розміщене на стінці нижньої частини прямої кишки та відхідникового каналу, утворене гілками ниж­нього підчеревного, верхнього і нижнього прямокишкових сплетень та нижніх прямокишкових нервів;

в) сечоміхурове сплетення (plexus vesicalis) розміщене на бічних стінках сечово­го міхура, утворене парасимпатичними гілками тазових нутряних нервів;

г) передміхурове сплетення (plexus prostaticus) розміщене на бічних, задній та нижній поверхнях передміхурової залози; утворене гілками нижнього підчеревного та міхурового сплетень;

ґ) печеристі нерви статевого члена (nn. cavernosi Penis) йдуть від передміхуро­вого сплетення через сечостатеву діафрагму до статевого члена. На спинці статево­го члена ці нерви з’єднується з дорзальним нервом статевого члена і досягають пе­черистих тіл;

д) печеристі нерви клітора (nn. cavernosi clitoridis) утворені гілками нижнього під­черевного сплетення, досягають клітора, пройшовши через сечостатеву діафрагму;

е) сплетення сім’явиносної протоки (plexus deferentialis) розміщене навколо сім’явиносної протоки, віддає гілки до сім’яних пухирців; утворене гілками ниж­нього підчеревного та міхурового сплетень;

є) матково-піхвове сплетення (plexus uterovaginalis) розміщене у приматковій сполучній тканині, переважно по боках матки та піхви, у вигляді парного скупчен­ня нервових вузлів і волокон; утворене гілками нижнього підчеревного та міхурового сплетень. Гілки матково-піхвового сплетення прямують до матки, піхви, мат­кових труб і яєчників.