Question

Immunoglobulins present in tears is
A)${ I }_{ g }A$
B)${ I }_{ g }M$
C)${ I }_{ g }C$
D)${ I }_{ g }E$

Answer 1

The antibody plays a major role in the immune function of the mucous membrane. In the association with the mucosal membrane that is produced and is found in a greater amount than all the other types of antibodies combined. This antibody represents 15% of the total immunoglobulin produced in the body.

Complete step by step answer:
-Tears consist of liquid present in the precorneal tear film and the conjunctival fornices. The total volume of the sphere is 5 to 20 ml.
-Most of the clear fluid is produced by the lacrimal gland. The secondary role in tear production is performed by the goblet cells and the accessory lacrimal glands.
-Tear consists of many substances like proteins, enzymes, lipids, metabolites, and electrolytes.
-The class of serum immunoglobulin that is ${ I }_{ g }A$ was described in 1959 and is the major immunoglobulins present in the external secretions.
-In the tears ${ I }_{ g }A$ immunoglobulin is found as IT act as an immunologic barrier to the adherence, colonization, and cellular entry of microbial organisms and antigenic macromolecules and protects the mucosal surface of the eye from them.

So, the correct answer is,”${ I }_{ g }A$”.

Additional information: Immunoglobulin M (${ I }_{ g }M$) - present in the blood and the lymphatic fluid. It is the first antibody made by the body to fight a new infection.
Immunoglobulin E (${ I }_{ g }E$) - present in a small amount in the blood and become in high amounts when the body comes in contact with an allergen or fighting infection from a parasite.
Immunoglobulin G (${ I }_{ g }G$) - it is present in the blood and the other body fluids and its most common antibody which protects against bacterial and viral infections.
Immunoglobulin D(${ I }_{ g }D$) - one percent of the proteins in the plasma membrane of B-lymphocytes is made by them where they express with another antibody i.e. ${ I }_{ g }M$.

Note:
-Immunoglobulin A (${ I }_{ g }A$): present in the lining of the respiratory tract and digestive system. It is also present in saliva, tears, and breast milk.
-Tears help in the washing of foreign bodies that enter the eye. It contains a substance called lysozyme that acts as an antibacterial action and works to prevent the entry of microbes and also prevent any type of infections caused by microbes.
-It also contains the component that helps in healing the damage caused to the surface of the eye.