Question: Phagocytosis is discovered by
Options:
Robert Koch
Elie Metchnikoff
Joseph Lister
Fanny Hesse
-Elie Metchnikoff, a Russian zoologist and immunologist, is credited with the discovery of phagocytosis in 1882.
-He observed that certain cells in starfish larvae engulfed and destroyed foreign particles, a process he named phagocytosis (from the Greek words "phagein" meaning to devour and "kytos" meaning cell).
-This discovery laid the foundation for understanding the cellular basis of immunity and the role of white blood cells in defending the body against infections.
🔑Key Points:
Phagocytosis
-Phagocytosis is the process of engulfment and destruction of solid particles such as bacteria, dead tissue and foreign particles by the cells.
​Phagocytes
–Â The cells performing phagocytosis are called phagocytes
-The cells are
-​Neutrophil
-Macrophage
-Monocytes
​Neutrophil
–Â Neutrophils are the most abundant type of granulocytes.
-They are composed of 40-70 percent of WBC.
-They are formed from the stem cells in the bone marrow
-Major functions are
-​Chemotaxis
-Anti-microbial function
-Phagocytosis by antibody opsonization
-Degranulation
Eosinophils
-Along with mast cells and basophils, they also control mechanisms associated with allergic reactions.
-Formed in the bone marrow
-Composed of 2-3 percent in WBC
​Polymorphs
-Polymorphonuclear (PMN) cells refer to the group of white cells known as granulocytes.
–Â That includes neutrophils, eosinophils, basophils, and mast cells.
-PMNs are a subtype of leukocytes.
​Basophils
-Basophils are a type of white blood cell
-Representing about 0.5% to 1% of circulating white blood cells.