Question

Choose the correct sequence of the layers of the alimentary canal from the inner to outer layer

• A. Serosa $\to$ Muscularis$\to$ Submucosa$\to$ Mucosa
• B. Muscularis$\to$ Serosa$\to$ Mucosa$\to$ Submucosa
• C. Mucosa$\to$ Submucosa$\to$ Muscularis$\to$ Serosa
• D. Submucosa$\to$ Mucosa$\to$ Muscularis$\to$ Serosa

Answer 1

The correct option is C Mucosa$\to$ Submucosa$\to$ Muscularis$\to$ Serosa

The wall of the alimentary canal basically has 4 layers. From the outer surface towards the inner side to the lumen (cavity) the layers are as follows:-
Serosa (visceral peritoneum) - it is the first layer. It is made up of squamous epithelium and areolar connective tissue.
Muscularis (muscular coat)- it is the second layer. It is composed of outer longitudinal and inner circular muscle fibres.
Submucosa- it is the third layer. It consists of loose connective tissue which is richly supplied with blood and lymphatic vessels and in some areas with glands.
Mucosa (mucous membrane) - it is the innermost layer lining the lumen of the alimentary canal. Since it secretes mucus to lubricate the inner lining of the gut it is called mucosa . This layer forms irregular folds (rugae) in the stomach.