CR WEEK1 Histology of the Hematopoietic System Quiz

– Blood is composed of 45% Blood Blood Cells (4 types: RBCs, WBCs, Platelets, and Plasma) and 55% Plasma. – Hematocrit measures the packed volume of Red Blood Cells (RBCs) in a blood sample. – Anticoagulants prevent clotting, Plasma is called serum when clotting components are removed. – RBCs, erythrocytes, are anucleate and biconcave with a size of 7.8 μm. They function only within the bloodstream, have a lifespan of 120 days, and are replaced by reticulocytes. – Platelets, derived from megakaryocytes, are involved in coagulation, forming an initial plug and a firm thrombus for haemostasis. – Leukocytes, white blood cells, are sub-classified into Granulocytes (neutrophils, eosinophils, and basophils) and Agranulocytes (lymphocytes and monocytes). – Neutrophils are multilobed, motile cells that patrol for microbial infections and kill invading pathogens using phagocytosis, degranulation, and NETs. – Eosinophils and Basophils are the least numerous WBCs, and they contain bright orange and basophilic granules, respectively. They are associated with allergic reactions, parasitic infections, and chronic inflammation. – Lymphocytes and Monocytes are similar in size to RBCs. Lymphocytes function in adaptive immunity, and Monocytes are the precursors of tissue-specific phagocytes. – The immune system cells, such as Lymphocytes, circulate in the blood until they reach secondary lymphoid organs like Lymph nodes. – Lymph nodes maintain and differentiate B cells, and they house T cells. They detect and react to lymph-borne antigens, and they are concentrated in specific regions such as axillae, groins, and mesenteries. – The Lymph node architecture includes a cortex, a medulla, and a capsule, with various reticular and immune cells present. – The Thymus is a bilobed organ responsible for T-cell differentiation, and it contains thymocytes. The thymic cortex is composed of epithelioreticular cells, and Hassal’s corpuscles are located in the medulla.

– Blood is composed of 45% Blood Blood Cells (4 types: RBCs, WBCs, Platelets, and Plasma) and 55% Plasma. – Hematocrit measures the packed volume of Red Blood Cells (RBCs) in a blood sample. – Anticoagulants prevent clotting, Plasma is called serum when clotting components are removed. – RBCs, erythrocytes, are anucleate and biconcave with a size of 7.8 μm. They function only within the bloodstream, have a lifespan of 120 days, and are replaced by reticulocytes. – Platelets, derived from megakaryocytes, are involved in coagulation, forming an initial plug and a firm thrombus for haemostasis. – Leukocytes, white blood cells, are sub-classified into Granulocytes (neutrophils, eosinophils, and basophils) and Agranulocytes (lymphocytes and monocytes). – Neutrophils are multilobed, motile cells that patrol for microbial infections and kill invading pathogens using phagocytosis, degranulation, and NETs. – Eosinophils and Basophils are the least numerous WBCs, and they contain bright orange and basophilic granules, respectively. They are associated with allergic reactions, parasitic infections, and chronic inflammation. – Lymphocytes and Monocytes are similar in size to RBCs. Lymphocytes function in adaptive immunity, and Monocytes are the precursors of tissue-specific phagocytes. – The immune system cells, such as Lymphocytes, circulate in the blood until they reach secondary lymphoid organs like Lymph nodes. – Lymph nodes maintain and differentiate B cells, and they house T cells. They detect and react to lymph-borne antigens, and they are concentrated in specific regions such as axillae, groins, and mesenteries. – The Lymph node architecture includes a cortex, a medulla, and a capsule, with various reticular and immune cells present. – The Thymus is a bilobed organ responsible for T-cell differentiation, and it contains thymocytes. The thymic cortex is composed of epithelioreticular cells, and Hassal’s corpuscles are located in the medulla.

Test your knowledge about the histological features and functions of the hematopoietic system, including blood as a connective tissue, stages of hemopoiesis, blood cell types, and the histological characteristics of bone marrow, thymus, lymph node, and spleen.