Question

Which of the following cells of connective tissues is/are absent in blood and lymph?
A. Antibody secreting cells
B. Phagocytic cells
C. Histamine secreting cells
D. Fibre secreting cells

Answer 1

Hint:- Blood consists of Red blood cells, White blood cells, blood platelets, and plasma. Lymph is a clear to white fluid tissue made of lymphocytes and white blood cells. It helps in transporting the white blood cells within the lymph nodes and also fights against infectious pathogens. Lymph is made of White blood cells, especially lymphocytes and chyle from intestines.

Complete answer:-
Antibody secreting cells (ASCs) are differentiated cells of the humoral immune response. ASCs differentiate from activated B cells in lymph nodes and circulate in blood and lymph to provide immunity against pathogens. A phagocyte is a cell that performs phagocytosis. Phagocytosis is a process of endocytosis by which a cell engulfs a foreign particle in blood and lymph forming an internal compartment called the phagosome.
Histamine is produced by basophils and mast cells found in blood and lymph. Histamine increases the permeability of the capillaries to white blood cells and allows them to fight pathogens in the infected tissues. The Fibre secreting cells are the fibroblast. It makes the fibers and is found in the connective tissues which provide strength like bone and cartilage.
Thus, the right option is D.

Note:- Lymph and blood differ in possessing the WBC levels. Lymph is the fluid that circulates throughout the lymphatic system and is formed from the interstitial fluid (collected through lymph capillaries). It is then transported through lymph vessels to lymph nodes and ultimately gets emptied into the right and left subclavian vein and thus mixes back with the blood.