Question

Select the incorrect matching. (a) Zona fasciculata - Glucocorticoids (b) \(\propto\) -cell - Glucagon (c) \(\beta\) -cell - Insulin (d) Follicular cells of thyroid \(-\mathrm{TCT}\)

Short answer

The incorrect matching is (d) Follicular cells of thyroid - TCT as Thyroid follicular cells are actually responsible for producing and secreting Thyroxine (T4) and Triiodothyronine (T3), not TCT.

Step-by-step solution

Verifying Option a

The Zona fasciculata is a layer of the adrenal cortex. It's mainly responsible for producing Glucocorticoids. Hence, matching Zona fasciculata and Glucocorticoids is correct.

Verifying Option b

Alpha (represented by the Greek letter \(\propto\)) cells of the pancreas are known to secrete Glucagon. Thus, this matching is also correct.

Verifying Option c

Similarly, Beta (denoted by the Greek letter \(\beta\)) cells of the pancreas are responsible for the secretion of Insulin. Therefore, matching \(\beta\) -cells with Insulin is correct.

Verifying Option d

Follicular cells of the thyroid are responsible for producing and secreting Thyroxine (T4) and Triiodothyronine (T3), not TCT. Therefore, this matching is incorrect.

Key concepts

Pancreas

The pancreas is an essential organ in the endocrine system, playing a vital role in regulating blood sugar levels. It contains various types of cells, including alpha and beta cells.

**Alpha Cells**

• Alpha cells are known for secreting glucagon.
• Glucagon is a hormone that raises blood glucose levels when they are too low.
• It works by promoting the conversion of glycogen into glucose in the liver.

**Beta Cells**

• Beta cells have the crucial job of producing insulin.
• Insulin is a hormone that helps lower blood glucose levels by facilitating the uptake of glucose into cells.
• This balance between glucagon and insulin ensures that our bodies maintain stable blood sugar levels.

Understanding the function of these cells is key to grasping how the pancreas contributes to the endocrine system and overall health.

Adrenal Cortex

The adrenal cortex is one of the main components of the adrenal glands, which are located on top of the kidneys. It's involved in producing a variety of hormones that are critical for body functions.

**Structure and Zones**

• The adrenal cortex is divided into three zones: zona glomerulosa, zona fasciculata, and zona reticularis.
• The zona fasciculata is the middle layer and it's primarily responsible for secreting glucocorticoids.

**Glucocorticoids**

• Glucocorticoids, such as cortisol, play a significant role in regulating metabolism and the body’s response to stress.
• They influence the immune system by reducing inflammation and helping the body manage stress-inducing situations.

This organ is crucial for maintaining a balance of various physiological processes and ensures body adapts to stress effectively.

Thyroid Gland

The thyroid gland is a butterfly-shaped gland located in the neck. It is a key player in regulating the body's metabolism, system growth, and development.

**Function and Hormones**

• Follicular cells in the thyroid produce two primary hormones: Thyroxine (T4) and Triiodothyronine (T3).
• These hormones are crucial for regulating the metabolic rate and affect almost every physiological process in the body.

**Thyroid Calcitonin (TCT)**

• It’s important to note that the follicular cells do not produce TCT. This hormone, also known as calcitonin, is actually produced by the parafollicular cells (C-cells) of the thyroid gland.
• Calcitonin helps regulate calcium levels in the blood by lowering them when they are too high.

The thyroid's ability to regulate these vital functions makes it indispensable to the body's well-being and hormonal balance.