Question

Auerbach’s plexus and Meissner’s plexus are located in the
A. Muscularis and submucosa layer respectively
B. Submucosa and muscularis layer respectively
C. Serosa and mucosa respectively
D. Submucosa and mucosa respectively

Answer 1

Hint: Auerbach’s plexus and Meissner’s plexus are located in the muscularis and submucosa layer respectively in the gastrointestinal tract. Here, in this question, we need to understand the layers of the gastrointestinal wall. For this, we will first write how many layers there are and sequence of layers.

Complete step-by-step answer:

The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the digestive tract or passageway that connects the mouth to the anus. There are four layers of the gastrointestinal tract.

Image- T.S of GI Wall showing the location of Auerbach’s plexus and Meissner’s plexus.

Meissner's plexus is located in the intestinal wall's submucosa, whereas Auerbach's plexus is located between the muscularis externa inner circular and outer longitudinal layers.
1. Mucosa- The mucosa is the gastrointestinal tract's innermost layer. It surrounds the tract's cavity (lumen) and comes into direct contact with digested food (chyme). The mucosa is composed of three layers-
1) The epithelium is the innermost layer. It is the site of the majority of digestive, absorptive, and secretory processes.
2) The lamina propria is a connective tissue layer within the mucosa.
3) A thin layer of smooth muscle called the muscularis mucosae.

2. Submucosa- The submucosa is a dense and irregular layer of connective tissue that branches into the mucosa and muscular layer via blood vessels, lymphatics, and nerves. On the inner surface of the muscular layer, it contains the submucous plexus and the enteric nervous plexus.

3. Muscularis- The muscular layer (also known as the muscularis propria) is a layer of muscle made up of two layers of muscle: inner and outer. The inner layer's muscle is arranged in circular rings around the tract, whereas the outer layer's muscle is arranged longitudinally. An extra layer, an inner oblique muscular layer, exists in the stomach. The myenteric or Auerbach's plexus is located between the two muscle layers. This regulates peristalsis.

4. Serosa- The gastrointestinal wall's outermost layer is made up of several layers of connective tissue and is classified as adventitia or serosa. Serosa covers the gastrointestinal tract within the peritoneum.

So, option A is the correct answer.

Note: For this question candidate must be aware of the correct sequence of gastrointestinal tract. Every layer has their own function which is important to know for this question.