Question

Match Column-I with Column-Il and select the correct option from the codes given below. Column-I \(\quad\) Column-II A. Neck cells (i) \(\mathrm{HCl}\), Intrinsic factor B. PeptidChief cells (ii) Mucus C. Parietal/Oxyntic cells (iii) Pepsinogen (a) \(\mathrm{A}-(\mathrm{ii}), \mathrm{B}-(\mathrm{iii}), \mathrm{C}-(\mathrm{i})\) (b) A-(iii), B-(ii), C-(i) (c) A-(i), B-(ii), C-(iii) (d) A-(ii), B-(i), C-(iii)

Short answer

A-(ii), B-(iii), C-(i), therefore, the correct option is (a).

Step-by-step solution

Identify the Functions of Cells in the Stomach

Begin by identifying what each type of cell mentioned in Column-I typically secretes or its primary function. Neck cells secrete mucus, which protects the stomach lining from the acidic environment. Chief cells, also known sometimes as peptic cells, produce pepsinogen, which is a precursor to the enzyme pepsin that digests proteins. Parietal, or oxyntic, cells secrete hydrochloric acid (HCl) which helps in digestion and also the intrinsic factor which is essential for the absorption of vitamin B12.

Associate Cells with their Secretions

Match each cell type with its appropriate secretion or role based on the biological functions identified in the previous step. A. Neck cells secrete mucus, so they match with (ii). B. Chief cells secrete pepsinogen, which matches with (iii). C. Parietal/Oxyntic cells secrete HCl and the intrinsic factor, which matches with (i).

Select the Correct Option

Using the matches made in Step 2, compare the options given in the exercise. The correct option is the one that matches the cell types with their correct secretions. That is option (a) A-(ii), B-(iii), C-(i).

Key concepts

Neck Cells Mucus Secretion

The inner lining of the stomach is dotted with specialized cells known as neck cells or mucous neck cells. These cells play a pivotal role in maintaining the delicate balance within the stomach's environment by secreting mucus. The mucus acts as a protective barrier, coating the stomach's surface to prevent it from the harsh acidic conditions created by digestive juices.

This protective function is essential for preventing ulcers and erosion of the stomach lining. The mucus produced by neck cells is slightly different from other mucus in the body; it is specially formulated to withstand the low pH brought about by gastric acids. When learning about the biology cell function identification, understanding the role of neck cells in mucus secretion is crucial. This safeguarding of the stomach's lining ensures that our digestive processes can occur without damaging our own cells.

Chief Cells Pepsinogen

Chief cells, or peptic cells, are another integral part of the stomach's anatomy. They are primarily responsible for secreting the zymogen pepsinogen. When pepsinogen comes into contact with the acidic environment in the stomach—specifically the hydrochloric acid produced by parietal cells—it undergoes a transformation into pepsin.

Understanding Pepsinogen Activation

Pepsinogen's conversion to pepsin, an active protease, is critical for the digestion of proteins. Pepsin breaks down the complex proteins into smaller peptides, a necessary step for their further digestion and absorption in the small intestine. Without the initial action of pepsin, protein digestion would be inefficient, underscoring the vital role of chief cells in enzyme secretion during digestion.

Parietal Cells Hydrochloric Acid

Parietal cells, also known as oxyntic cells, are remarkable for their ability to secrete hydrochloric acid (HCl) into the stomach. This acid performs multiple functions:

• It creates an acidic environment that activates pepsinogen into pepsin.
• It helps in breaking down food, especially tough protein fibers.
• It acts as a first line of defense against pathogens ingested with food.

Additionally, parietal cells produce intrinsic factor, an essential component for vitamin B12 absorption in the small intestine. The unique biology cell function identification of parietal cells also includes regulating the stomach's acidity, making them key players in both enzyme activation and nutrient absorption.

Biology Cell Function Identification

In the realm of biology, the identification of cell functions is fundamental for understanding how living organisms operate. The stomach cells, such as neck, chief, and parietal cells, each have unique tasks that contribute to the organ's overall function. These cells can be identified based on what they secrete and their role in digestion.

For example, microscopy and staining techniques reveal the location and structure of these cells, aiding in their identification. Recognizing the specific functions of these cells is crucial for understanding how the body processes food and how it protects itself from potential harm. The interplay of these various cells and their secretions exemplifies the complexity and efficiency of the human digestive system.

Enzyme Secretion in Digestion

Enzyme secretion plays a pivotal role in the digestive process. Enzymes are biological catalysts that speed up chemical reactions, such as the breakdown of food into absorbable nutrients. In the stomach, pepsinogen is secreted by chief cells and converted into pepsin, highlighting the necessity of an enzyme for protein digestion.

Throughout the digestive tract, different types of enzymes are secreted to specifically break down carbohydrates, fats, and nucleic acids. These enzymes are carefully regulated and released in response to the presence of food, showcasing the body’s ability to coordinate its digestive functions precisely. A solid grasp of enzyme secretion is thus essential for appreciating the efficiency and intricacy of the digestion process.