Problem 27 - Arihant Objective Approach to Organic Chemistry for IIT JEE and NEET all Medical Entrances Part 4

Question

Insulin is secreted by: (a) stomach (b) intestine (c) pancreas (d) brain

Step-by-Step Solution

Answer

Insulin is secreted by the pancreas (c).

Step 1: Understand the Question

The question asks which organ secretes insulin. Insulin is a hormone crucial in regulating blood sugar levels by facilitating the uptake of glucose into cells.

Step 2: Recall Relevant Biological Concepts

Recall that insulin is a hormone related to the regulation of blood glucose. It plays a significant role in metabolism and the storage of carbohydrates, fats, and proteins.

Step 3: Review Each Option

- (a) Stomach: The stomach secretes digestive juices and enzymes, but not insulin. - (b) Intestine: The intestine is involved in nutrient absorption, not insulin secretion. - (c) Pancreas: The pancreas produces and secretes insulin. - (d) Brain: The brain doesn't directly secrete insulin.

Step 4: Select the Correct Answer

Based on the understanding that insulin is secreted by the pancreas, the correct choice is (c) pancreas.

Key Concepts

Pancreas Function

The pancreas is a vital organ situated behind the stomach, playing an important role in both the digestive and endocrine systems. This gland functions in two primary ways:

• Exocrine Function: It produces enzymes that aid in digesting food, particularly fats, carbohydrates, and proteins. These enzymes are released into the small intestine, helping to breakdown nutrients so they can be absorbed into the bloodstream.
• Endocrine Function: The pancreas contains clusters of cells known as Islets of Langerhans, which are responsible for producing essential hormones like insulin and glucagon. These hormones are crucial for regulating blood sugar levels.

Among its various functions, the secretion of insulin makes the pancreas especially important in managing energy balance in the body. This dynamic balance is crucial for overall health and the prevention of diseases such as diabetes.

Hormone Regulation

Hormones are biochemical substances that play vital roles in orchestrating complex physiological processes. Hormone regulation involves a delicate balance maintained by feedback mechanisms in the body.

In the context of insulin, its release is primarily controlled by blood sugar levels:

• When blood sugar is high, such as after a meal, the pancreas releases more insulin to facilitate glucose uptake by cells, helping to lower and stabilize the sugar level.
• Conversely, when blood sugar is low, insulin secretion decreases, while glucagon (another hormone from the pancreas) is released to help raise the sugar levels by prompting the liver to release stored glucose.

These feedback loops ensure that energy derived from food is properly managed, supporting cellular function and overall metabolism. A malfunction in hormone regulation can lead to significant health issues, including metabolic syndromes.

Blood Sugar Levels

Blood sugar levels, also known as blood glucose levels, measure the concentration of glucose present in the blood. Glucose is a primary energy source for the body's cells, and its regulation is critical for maintaining homeostasis.

The normal fasting blood sugar level ranges between 70 to 99 mg/dL, but these levels can rise naturally after consuming a meal. Here’s how it works:

• After eating, carbohydrates are broken down into glucose, leading to an increase in blood sugar levels. The pancreas responds by secreting insulin.
• Insulin helps cells to absorb glucose and use it for energy, while assisting in storing excess glucose as glycogen in the liver for later use.
• When blood glucose levels drop, glycogen can be converted back into glucose to maintain balanced sugar levels.

This systemic regulation prevents drastic spikes and drops in blood sugar, supporting optimal body function. Prolonged deviations from normal blood sugar levels can be indicative of conditions like diabetes, necessitating careful monitoring and management.