Submucous plexus

Enteric nerves control intestinal smooth muscle action and are connected to the brain by the autonomic nervous system. IBS is thought to result from dysregulation of this brain-gut axis. The enteric nervous system is composed of two gan-glionated plexuses that control gut innervation the submucous plexus (Meissner s plexus) and the myenteric plexus (Auerbach s plexus). The enteric nervous system and the central nervous system (CNS) are interconnected and interdependent. A number of neurochemicals mediate their function, including serotonin (5-hydroxytryptamine or 5-HT), acetylcholine, substance P, and nitric oxide, among others. 

Figure 9.52 shows the blood supply to the rectal area. The main artery to the rectum is the superior rectal (haemorrhoidal) artery. Veins of the inferior part of the submucous plexus become the rectal veins, which drain to the internal pudendal veins. Dmg absorption takes place through this venous network. Superior haemorrhoidal veins connect with the portal vein and thus transport dmgs absorbed in the upper part of the rectal cavity... 

A. Anatomic Aspects of the ANS The motor (efferent) portion of the ANS is the major pathway for information transmission from the central nervous system (CNS) to the involuntary effector tissues (smooth muscle, cardiac muscle, and exocrine glands Figure 6-1). The enteric nervous system (ENS) is a semiautonomous part of the ANS, with specific functions for the control of the gastrointestinal tract. The ENS consists of the myenteric plexus (plexus of Auerbach) and the submucous plexus (plexus of Meissner) and includes inputs from the parasympathetic and sympathetic nervous systems. 

Mueller, K., Michel, K., Krueger, D., Demir, I.E., Ceyhan, G.O., Zeller, F., Kreis, M.E., and Schemann, M. (2011) Activity of protease-activated receptors in the human submucous plexus. Gastroenterology 141, 2088-2097. 

Fig. 9. Rectum biopsy in ACD. Ganglion cells of the submucous plexus are converted to foam cells. Paraffin section, van-Gieson stain, enlargement 400-fold. (Fig. 7 from Dubach and Gloor 1966. Reproduced with permission of Georg Thieme Verlag, Stuttgart)...

Tachykinins Neurons localized in the submucous and myenteric plexuses enterochromaffin cells in gut epithelium 1. Regulates vasomotor and gastrointestinal smooth muscle contraction 2. Mucus secretion and water absorption Direct and indirect activation of neurons in submucosa and myenteric plexuses in gut epithelium... 

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