Problem 14 - Objective Biology for NEET

Question

Basophil secrete (a) Histamine (b) Serotonin (c) Heparin (d) All of these

Step-by-Step Solution

Answer

The correct answer is (d) All of these. Basophils secrete Histamine, Serotonin and Heparin.

Step 1: Understanding the role of Basophils

Basophils are a type of white blood cell that play a critical role in your body's immune response. When an allergen enters your body, Basophils release substances to combat this allergen.

Step 2: Identifying the substances Basophils secrete

Basophils are known to secrete several substances, among them are Histamine, Serotonin and Heparin. Histamine enhances the inflammatory response, Serotonin aids in regulating mood and body temperature, and Heparin prevents blood clotting.

Step 3: Matching the substances with the options given

In the given options, Histamine, Serotonin and Heparin are all mentioned, which confirms that Basophils do secrete all of these substances. Hence, all of the given options (a, b and c) are correct.

Key Concepts

Histamine

Histamine is a naturally occurring compound that plays an integral part in your body's immune response. Primarily stored in the granules of mast cells and basophils, it is released during inflammatory and allergic reactions. Once dispatched, histamine will expand the blood vessels, increasing blood flow to the site of an allergen invasion or injury. This vasodilation helps other immune cells to access the affected area more rapidly.

Role in Allergic Reactions

During an allergic reaction, histamine is responsible for symptoms like redness, swelling, and itching. It functions by binding to histamine receptors on nearby cells, leading to an increase in blood vessel permeability, which allows immune cells and proteins to access the tissue in the affected area.

By understanding the pivotal role of histamine in immune responses, students can appreciate why antihistamines are often used in treating allergies—they serve to block histamine receptors and mitigate these reactions.

Serotonin

Serotonin, often referred to as the 'feel-good' neurotransmitter, has diverse roles that extend beyond the central nervous system. While it is well-known for its role in mood regulation and creating a sense of well-being, serotonin is also secreted by basophils and other types of cells within the immune system.

Impact on Immune Response

Serotonin contributes to the regulation of immune responses. It can influence the intensity and quality of inflammatory reactions, with some studies suggesting it acts to enhance the overall inflammatory process. Additionally, within the gut, serotonin helps manage the movement of the intestines, and in the blood, it plays a part in clotting processes. Therefore, serotonin's role goes beyond neurotransmission, serving multiple critical functions across various physiological processes.

Heparin

Heparin is a potent anticoagulant, which means it helps to prevent blood clots from forming within the vascular system. Produced by basophils and mast cells, heparin is vital in maintaining the fluidity of blood and preventing potentially dangerous clotting events that may lead to conditions like deep vein thrombosis or pulmonary embolism.

Therapeutic Uses

Outside of the body's natural use of heparin, it is also widely used in medical settings as a medication to prevent and treat blood clots, especially after surgeries or in those with conditions that put them at high risk for clot formation. By comprehending heparin's role, students can see the connection between the body's natural defenses against clotting and how similar mechanisms are harnessed therapeutically.

Immune Response

The immune response is the body's defense mechanism against foreign invaders such as pathogens. It involves a complex network of cells, molecules, and tissues that work together to identify and neutralize threats. Basophils are a key component of this defense strategy, especially when it comes to allergic reactions and parasitic infections.

Role in Defense

When an allergen or pathogen is detected, basophils are activated and release their stored compounds, such as histamine, serotonin, and heparin. These substances aid in mounting an effective response to eliminate or contain the threat. Histamine and serotonin can recruit other immune cells to the site, while heparin ensures proper blood flow by preventing clot formation. The orchestration of these events is essential for a robust immune response, illustrating the importance of each component, down to the cellular level.