Explains the enteric nervous system, a network of over 100 million neurons running from the oesophagus to the anus, and its two plexuses: the myenteric (Auerbach's) plexus between the muscle layers and the submucosal (Meissner's) plexus. Covers its gut functions such as motility, secretion, local blood flow and mucosal transport, its independence from the brain and spinal cord, and the stepwise mechanism of peristalsis moving the food bolus forward through excitatory and inhibitory neurotransmitters.
Topic 29 of 44 in the MU Sofia syllabus for Anatomy (PNS) (Medicine, Year 2). The free AceMed note covers it in 5 sections, about 368 words (3 min of reading), with 10 flashcards.
In this note
ENTERNIC Nerve System (Seconed brain)
Structure & Location :
Functions :
Independence :
Mechanism
Structure & Location :
The ENS consists of a network of more than 100 million nerve cells(neurons) embedded in the lining of the gastrointestinal system.
It extends from the esophagus to the anus and is distributed throughout the entire digestive tract.
The neurons of the ENS are collected into two types of ganglia:
Myenteric (Auerbach's) plexus: Located between the inner and outer layers of the muscularis externa. ← Controls digest. tract motility
Submucosal (Meissner's) plexus: Located in the submucosa 1. ← - Local secretion - Absorption - Local movements
Functions :
The ENS controls various aspects of gastrointestinal function, including:
Motor functions: Regulating muscle movements in the intestines (such as peristalsis).
Secretion of gastrointestinal enzymes: Coordinating the release of digestive enzymes.
Local blood flow: Modulating blood supply to different parts of the gut.
Mucosal transport: Facilitating the movement of nutrients and waste.
Immune and endocrine functions: Influencing immune responses and hormonal signaling 2 3.
Independence :
The ENS is capable of acting independently of the brain and spinal cord.
It is often referred to as the "second brain" due to its intricate control over gut functions.
Although it can operate independently, it may still receive innervation from the vagus nerve and prevertebral ganglia.
Notably, studies have shown that the system remains functional even with a severed vagus nerve 1.
Continue reading free
The whole note, all 5 sections, is free with an AceMed account, with its 10 flashcards. Premium adds flashcard recall, highlights and Ask AI.
