Question

Mucosa forms rugae in the?
A) Small intestine
B) Large intestine
C) Oesophagus
D) Stomach

Answer 1

Hint: Rugae are structures produced by the folding of the wall of an organ. Most commonly rugae are known as the gastric rugae which are present in the internal surface of the stomach. In the stomach, rugae are made from mucosa and submucosa layers. These are used in the expansion of the stomach.

Complete answer: The mucosa is a mucus membrane. It is the moist inner lining of some organs and body cavities such as the nose, mouth, lungs and stomach. A Mucus is a thick, slippery fluid. In the stomach, the empty state is contracted and its mucosa and submucosa are released into detached folds called rugae. These rugae are also known as gastric folds or gastric rugae. When the stomach is distended with food, the rugae are ironed out and flat. These are present in the entry of gastric pit which helps in the formation of gastric glands. They provide elasticity to the stomach when food enters the stomach. These are very helpful for the action of the mechanoreceptor to release pressure in the stomach. Whereas, rugae are absent or not formed in the small intestine, large intestine and oesophagus. The muscular layer releases the stomach acid which is regulated by histamine hormone.
Hence the correct answer is option D.

Note: Rugae only manifests when an organ or tissue is relaxed. For example, rugae manifest within the stomach when it is deflated or relaxed. Mucosa forms rugae only in the stomach. Gastritis is caused when gastric folds become very thick due to inflammation.