Biology - Digestion and Absorption Question with Solution | TestHub
In a child, a genetic disorder leads to the mucous cells of salivary glands being completely nonfunctional, while serous cells remain normal. Over time, the child begins to experience irritation of the buccal mucosa and minor scratches in the lining of food pipe. Which of the following best explains the reason for these symptoms?
Options:
Answer:
Solution:
Salivary glands contain two main types of secretory cells: serous cells and mucous cells.
Serous cells secrete a watery fluid containing enzymes such as salivary amylase and lysozyme. Since the serous cells are normal in the child, the secretion of these enzymes and the watery component of saliva remains unaffected.
Mucous cells secrete mucus, which is a thick, viscous fluid containing mucin. Mucus plays a crucial role in lubricating the food bolus, facilitating smooth swallowing, and protecting the mucosal lining of the oral cavity and esophagus from mechanical excoriation or scratches.
Due to the nonfunctional mucous cells, there is a deficiency of mucus in the saliva. This leads to inadequate lubrication of the food bolus, which causes mechanical irritation of the buccal mucosa and minor scratches in the lining of the food pipe during swallowing.
Answer: Deficiency of mucus leading to inadequate lubrication of food bolus.
