Components, development and functions of res(reticulo-endo-thelial cells)

its physio presentation

1. Topic: COMPONENTS OF RES DEVELOPMENT OF RES FUNCTIONS OF RES

2. Reticuloendothelial system Also known as: Monocyte-Macrophage System Mononuclear Phagocytic System Lymphoreticular System

3. Reticuloendothelial System ( RES ) The total combination of monocytes, mobile macrophages, fixed tissue macrophages and few specialised endothelial cells in the bone marrow, spleen and lymph nodes is called RES.

4. Components of res Basically it is formed by two different types of tissues: Primary lymphoid organs Secondary lymphoid organs

5. PRIMARY LYMPHOID ORGANS Includes all those organs where the cells of RES are formed and get matured. Includes: Bone Marrow Thymus SECONDARY LYMPHOID ORGANS Includes the sites where the cells of RES functions Includes: Lymph nodes Tonsils Spleen Kuppfer cells , Microglia MALT ( mucosa associated lymphoid tissues)

6. Reticuloendothelial system System of cells which have highly phagocytic properties. RES consists of: Monocytes Macrophages Mobile(wandering) tissue macrophages Fixed tissue macrophages Endothelial cells(bone marrow, spleen, lymph node)

7. Monocytes Largest leukocytes. Immature cells present in blood to fight infectious agents After 72 hours enter the tissues to become “tissue macrophages”. In tissue they swell to become large in size and cytoplasm is filled with lysosomes.

8. macrophages MOBILE TISSUE MACROPHAGES Some macrophages are mobile and they can group together to become one phagocytic cell in order to ingest larger foreign particles. FIXED TISSUE MACROPHAGES Often remains fixed to their organs they filter and destroy objects which are foreign to the body such as bacteria and viruses.

9. Fixed tissue macrophages Liver Kupffer cells Lungs Alveolar macrophages Skin Langerhans cells Connective tissue Histiocytes CNS Microglia Bones Osteoclasts Spleen/Bone marrow/lymph nodes Reticular or Dendritic cells

10. Kupffer’s cells of liver

11. Alveolar macrophages in lungs

12. Functions of macrophages Engulf inorganic particulate matters(carbon and dust particles). Organic foreign matters such as thorn, fish bone, catgut are destroyed by enzyme action and lysis. Help T & B lymphocyte in the acquired immunity by presenting antigens.

13. Endothelial cells

14. Functions of res It plays an important role in formation of RBCs and WBCs.

15. Functions of res Phagocytic function: Bacteria, other foreign bodies and tissue debris engulfed and digested by lysosomes of the macrophages( direct). Destruction of senile red blood cells. Storage and metabolism of iron. Immune function: Processing antigens and antibodies production (indirect).

16. Phagocytosis( Direct) Phagocytosis is a part of natural or innate immune process Macrophages are the powerful Phagocytic cells: Ingest up to 100 bacteria Ingest larger particles such as old RBCs Get rid of waste products

17. Neutrophils secrete the class of enzymes called lysozyme and destroying the bacteria by the process of phagocytosis. Monocytes engulf large particulate matters( dead tissue cell and senile cells).Also involve in Phagocytosis.

18. Direct anti inflammatory

19. Indirect immune function of res Ingest foreign body, process it and present it to lymphocytes. Indirect role of RES is when an antigen( foreign particles) comes in body our lymphatic system stimulate white blood cells produce antibodies to take the action.

20. Disorders of res TUBERCULOSIS (TB) MALIGNANT DISEASE

21. Disorders of res LEUKAEMIA LYMPHOMA

22. Spleen Bean shaped organ It is situated in the left hypochondriac region left upper part of abdomen, behind the stomach and just below the diaphragm. Purplish in colour. Weigh about 150g/m Largest lymphoid organ.

23. Structure of spleen White Pulp: Thick sleeves of lymphoid tissues that provides the immune function of the spleen. Red Pulp: Surround white pulp composed of vinous sinuses filled with whole blood and splenic cords of reticular connective tissue rich in macrophages.

24. Function of spleen Formation of RBCs Removal of unwanted elements from the blood Reservoir function Role in defence mechanism Storage and metabolism of iron

25. Splenomegaly The enlargement of spleen is called splenomegaly. It happens during the following conditions: Increased the phagocytosis by macrophages as in any infections. Increased destruction of erythrocytes as in malaria. Abnormal increase in lymphocytes production as in leukaemia.

26. Diseases of spleen SICKLE CELL DISEASE THROMBO CYTOPENIA SPLEEN CANCER This is an inherited form of anemia . It results in abnormality in the oxygen carrying protein haemoglobin found in RBCs. If the spleen becomes enlarged, it may have low blood count platelets. Due to low platelets spontaneous bleeding occurs. Cancer start in spleen is primary cancer. If it spreads in the spleen is known as secondary cancer. Both are rare.