Question

Which one of the following pairs of the kind of cells and their secretion is correctly matched? (a) Oxyntic cells - a secretion with pH between \(2.0\) and \(3.0\) (b) Alpha cells of islets of Langerhans - secretion that decreases blood sugar level (c) Kupffer cells - a digestive enzyme that hydrolyses nucleic acids (d) Sebaceous glands - a secretion that evaporates for cooling

Short answer

The correctly matched pair of cells and their secretion is (a) Oxyntic cells - a secretion with pH between 2.0 and 3.0.

Step-by-step solution

Review Biological Functions of Given Cells

Understand the role and function of each provided cell type in the body. Oxyntic cells, also known as parietal cells, are located in the stomach lining and are responsible for secreting gastric acid which has a low pH. Alpha cells of the islets of Langerhans in the pancreas secrete glucagon, a hormone that increases blood sugar levels. Kupffer cells are macrophages in the liver that deal with detoxification and pathogen removal but do not secrete digestive enzymes. Sebaceous glands are found in the skin and secrete sebum to lubricate and waterproof the skin, and have no role in cooling through evaporation.

Match Cell Types to Their Secretions

Compare the secretions with the known functions of each cell type. Oxyntic cells indeed secrete gastric acid which has a pH between 2.0 and 3.0; therefore, option (a) is a correct match. Alpha cells secrete glucagon, which actually increases, not decreases, blood sugar levels, making option (b) incorrect. Kupffer cells do not secrete digestive enzymes, so option (c) is not correct. Sebaceous glands do not secrete for the purpose of cooling through evaporation, hence option (d) is incorrect.

Identify the Correct Match

After reviewing the roles and secretions of the listed cell types, identify that the correct match is the pair in which the known biological function aligns with the stated secretion in the options. The only option that aligns correctly is (a) Oxyntic cells - a secretion with pH between 2.0 and 3.0.

Key concepts

Understanding Oxyntic Cells and Gastric Secretion

Oxyntic cells, also known as parietal cells, play a crucial role in our digestive system. They are located in the lining of the stomach and are responsible for secreting gastric acid, which has a low pH of about 2.0 to 3.0. This acidic environment is essential for the activation of enzymes that break down proteins in our food, and it also acts as a barrier to pathogens. The correct pairing in the exercise, option (a), reflects the true function of oxyntic cells.

Gastric acid secretion by oxyntic cells is a complex process regulated by signals such as gastrin, histamine, and acetylcholine. Understanding the role of these cells helps us appreciate how the body maintains a balance in digestive functions and protects against harmful microorganisms.

Alpha Cells and the Role of Glucagon

Alpha cells are found in the pancreas within the clusters known as islets of Langerhans. They are important for our body's glucose metabolism. Contrary to what option (b) suggests, alpha cells do not decrease blood sugar levels; instead, they secrete a hormone called glucagon. Glucagon plays a critical role in raising blood glucose levels by stimulating the conversion of stored glycogen in the liver into glucose that is then released into the bloodstream.

This function is particularly important when you haven't eaten for a while or when you need extra energy, such as during exercise. The alpha cells ensure that our bodies have a constant and steady supply of glucose, which is a primary source of energy for our cells.

Kupffer Cells and Their Function in the Liver

Kupffer cells are specialized macrophages located in the liver, and they form an important part of the body's immune system. These cells are tasked with filtering and removing pathogens, worn-out blood cells, and other debris from the blood as it passes through the liver. They do not secrete digestive enzymes, which makes option (c) incorrect. Instead, their primary role involves detoxification and providing defense against infections.

Kupffer cells also play a part in the metabolism of substances and immune regulation in the liver. By being part of the liver's reticuloendothelial system, they help maintain overall liver health and function.

Sebaceous Glands and the Secretion of Sebum

Sebaceous glands, which are found throughout the skin except for on the palms of the hands and the soles of the feet, produce an oily substance called sebum. This secretion is important for maintaining the health of your skin by lubricating and waterproofing it, preventing dryness and cracking. Sebum also carries antioxidants and has antimicrobial properties. Option (d) incorrectly states that sebum is used for cooling the skin through evaporation; instead, its main purpose is to protect and enhance the skin barrier.

These glands can be influenced by hormonal changes, which is why they are often more active during puberty. By understanding the role of sebaceous glands, we can better comprehend issues like acne, which occur when these glands become overactive or clogged.