Immunology - Problem Drill 04: Structure and Functions of the Immune System

Transcription

1 Immunology - Problem Drill 04: Structure and Functions of the Immune System Question No. 1 of Which one of the following is non-encapsulated and less organized secondary lymphoid organ? Question #1 (A) Spleen (B) Thymus (C) MALT (D) Lymph nodes Spleen is a secondary lymphoid organ but it is a systemic organ which is well organized and encapsulated. Thymus is a primary lymphoid organ! C. Correct! MALT is a part of mucosal system which is less organized and non-encapsulated. Lymph nodes are a secondary lymphoid organ but it is a systemic organ which is well organized and encapsulated. Try to remember the basis of classification of primary and secondary lymphoid organs. Also try to remember the flow chart of classification of lymphoid organs.

2 Question No. 2 of At what age does the thymus reach its maximal size? Question #2 (A) During the first year of life (B) Puberty (C) Between 40 to 50 years of age (D) During the fetal life It is still in the stage of development. B. Correct! After puberty, it undergoes spontaneous progressive involution, indicating that it functions best in early life. It s too late! This is the stage at which it just starts developing. Try to understand the structure and function of thymus in detail. By understanding its structural and functional aspects, its role in immune system of the body, it will make easier to answer these types of questions. Try to learn the structures and functions of other organs in the similar way.

3 Question No. 3 of What effect would removal of bursa of Fabricius (bursectomy) have on chickens? Question #3 (A) Lack of Humoral Immunity. (B) Lack of Cell mediated Immunity. (C) Over production of B-cells and T-cells. (D) It will not have any effect on the immune system. A. Correct! Bursa of fabricius is the primary site for the development of B-cells and is ultimately responsible for the active Humoral Immunity. Cell Mediated Immunity is because of T-lymphocytes. T-lymphocytes are developed in thymus and not in bursa of Fabricious. Bursectomy results in the lack of B-cells and nothing to do with production of T- cells. Bursa of Fabricious is a primary lymphoid organ and plays a prime role in the immune system. Try to learn and remember the Structure and functions of all organs of the Immune System. Go through each and every slide of the tutorial meticulously and be master in role of each and every organ/cell involved in the immune system.

4 Question No. 4 of Macrophages formed in the kidney are designated as. Question #4 (A) Osteoclasts (B) Microglial cells (C) Histocytes (D) Messangial cells These are located in the bone. These are located in the brain. These are located in the connective tissue. D. Correct! These are the macrophages formed in the kidney. Try to recall the classification of mononuclear cells. And remember Macrophages are dispersed throughout the body. They are named according to their tissue location. You can prepare a chart for it!

5 Question No. 5 of The cells that have a multilobed nucleus and a granulated cytoplasm that stains with both acid and basic dyes are. Question #5 (A) Basophils (B) Neutrophils (C) Eosinophils (D) Monocytes Basophils are granulocytes but they take the basic stain as their name suggests, also they don t have multilobed nucleus. B. Correct! The neutrophils have a multilobed nucleus and a granulated cytoplasm that stains with both acid and basic dyes; it is also called polymorphonuclear leukocyte (PMN). Eosinophils are granulocytes but they take the acidic stain as their name suggests, also they don t have multilobed nucleus. These are agranulocytes! Try to remember the basis of classification of all the cells involved in the immune response. Granulocytes and agranulocytes are divided on the basis of their cytoplasmic content and the dyes by which they are stained. Slide number 30 of the tutorial can help you in this regard.

6 Question No. 6 of The dye that stains Basophils is. Question #6 (A) Eosin red (B) Methylene Blue (C) Both A and B (D) None of the above It stains Eosinophils as its name suggests. B. Correct! It is the basic dye that stains Basophils. As its cytoplasmic content indicates, it cannot take both acidic and basic dyes. There IS one correct answer. Try to remember the basis of classification of all the cells involved in the immune response. Granulocytes and agranulocytes are divided on the basis of their cytoplasmic content and the dyes by which they are stained. Slide number 30 of the tutorial can help you in this regard.

7 Question No. 7 of Circulatory Dendritic cells in the lymph are called as. Question #7 (A) Veiled cells (B) Langerhans cells (C) Monocytes (D) Null cells A. Correct! These are the cells present in the lymph and are circulating to process and present antigen to TH cells. These are the Dendritic cells, but are present in the epidermis and mucous membrane and do not circulate. Monocytes are the mononuclear phagocytic cells and not Dendritic cells. These are not Dendritic cells. Try to remember the basis of classification of all the cells involved in the immune response. Granulocytes and agranulocytes are divided on the basis of their cytoplasmic content and the dyes by which they are stained. Go through all the slides meticulously.

8 Question No. 8 of The group of lymphocytes in the peripheral blood which do not express the membrane molecules and receptors are called as. Question #8 (A) Kupffer cells (B) Null cells (C) T-lymphocytes (D) IgG Kupffer cells are not lymphocytes, but they are macrophages present in the liver. B. Correct! Null cells are the small group of lymphocytes present in the peripheral blood which do not express the membrane molecules and receptors that distinguish T-cell and B- cell lineages. T-lymphocytes express membrane molecules and surface receptors. IgG are not the cells, but antibody molecules are secreted by B-cells. Try to learn and remember the concept Sheet given in the tutorial summarizing the properties of all cells and organs of the immune system.

9 Question No. 9 of CD8+ T-cells react with the cells that process endogenous antigen. These cells express which one of the following molecules? Question #9 (A) MHC class II molecules (B) IgG molecules (C) MHC class I molecules (D) Both MHC class I and class II molecules The MHC class II molecules mediate presentation of exogenous or externallyproduced antigens and react with CD4+ cells. These are not involved in the processing and presentation of antigen. C. Correct! The MHC class I molecules mediate presentation of endogenous or intracellularlyproduced proteins. CD8+ cells recognize antigens that are processed through an endogenous pathway and presented by infected or transformed cells expressing MHC class-i molecules. Both molecules are not involved in the processing of endogenous antigen. Try to learn and remember the details of the processing and presentation of antigen by MHC molecules.

10 Question No. 10 of The thinly walled vessels through which the fluid and the cells of the lymphatic system moves through the lymph nodes and ultimately into the thoracic duct, where it joins the blood stream are. Question #10 (A) RES (B) Lymphatic traffic (C) Circulating vessels (D) Lymphatic vessels The RES consists of the phagocytic cells located in reticular connective tissue, primarily monocytes and macrophages. These cells accumulate in lymph nodes and the spleen. Immunity depends on continuous movement of lymphoid cells through blood, tissue and lymph. Lymphoid cells travel to the secondary lymphoid organs of the spleen, lymph nodes and Peyer's patches to encounter antigens acquired from the environment via blood, lymph or across mucous membranes. There is no such a term in immunology. D. Correct! Lymphatic vessels perform the specified function. Go through each and every slide of the tutorial meticulously and be master in role of each and every organ/cell involved in the immune system. Also try to learn and remember the concept Sheet given in the tutorial summarizing the properties of all cells and organs of the immune system.