sqadia.com V-Learning™ provides best medical video lectures for Medical students and medical professionals. This medical lecture of ‘Immune system: phagocytosis and inflammation’ comprehensively explains cells of immune system, generation of immune response, origin and regulation of lymphocytes. Alongside this, lymphoid organs and tissues, NOD-like receptors, TOLL-like receptors have been shed light upon. Conclusively, the underlying mechanisms of phagocytosis and inflammation have also been delineated.
Cells of Immune System
This section discusses about various cells of immune system. Immune response generation involves the effort of both the innate and adaptive system which are mediated by leukocytes. Pattern recognition receptors (PRRs) are of two types i.e. soluble and insoluble. Moreover, cells involved in immune response like basophils, eosinophils etc have been discussed. Furthermore, the role of each cell type along with function of lymphocytes (T and B cells) has been elucidated.
Organs and Tissues
Organs and tissues are discussed in this section. Primary lymphoid organs are of two types i.e. bone marrow and thymus. Maturation of T-cells and B-cell maturation has been conferred about. Secondary lymphoid organs include spleen, lymph nodes, and mucosal associated lymphoid tissue (MALT). Highly organized lymphoid tissues are SALT-skin associated lymphoid tissue and MALT-mucosal associated lymphoid tissue. Whereas, the loosely associated cellular complexes (BALT-bronchial associated lymphoid tissue) have also been highlighted.
Receptors for Phagocytosis
The prime focus of this section is on the several receptors for phagocytosis. This process employs two mechanisms viz non-opsonic or opsonic recognition. The cytosolic NOD-like receptors sense infection and stress via the recognition of pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). On the contrary, signaling via toll-like receptors (TLRs) has been comprehensively elaborated.
The process of phagocytosis has been elucidated by Zain Arfeen in this section. Steps involved in phagocytosis have been primarily explained. Lysosomes, significant structures in the process, deliver a variety of hydrolases such as lysozyme. Phagocytic cell lysosomes contain enzymes that produce toxic reactive oxygen species (ROS) like superoxide radical (02), hydrogen peroxide (H202) which has also been expounded in detail.
In this section, Zain Arfeen sheds light on inflammation. Acute inflammation is the immediate response of the body to injury or cell death. It begins when injured tissue cells release chemokines that activate the endothelium of nearby capillaries. The development of chronic inflammation occurs slowly and is characterized by dense tissue infiltration of lymphocytes and macrophages into the affected site and the formation of new connective tissue, leading to permanent tissue damage.