Heamatology

Question 1

What is haematopoiesis, and where does it primarily occur in adults?

Answer 1

Haematopoiesis is the process of blood cell formation, primarily occurring in the bone marrow in adults.

Question 2

Describe the major types of mature blood cells.

Answer 2

The major types include red blood cells (RBCs or erythrocytes), white blood cells (WBCs or leukocytes), and platelets (thrombocytes).

Question 3

What are the different forms of leukopoiesis, and what cells do they produce?

Answer 3

Leukopoiesis includes granulopoiesis (granulocytes), lymphopoiesis (lymphocytes), and monopoiesis (monocytes).

Question 4

What are the key terms associated with abnormal blood cell counts?

Answer 4

Terms include leukopenia, leukocytosis, thrombocytopenia, thrombocytosis, neutropenia, neutrophilia, lymphopenia, lymphocytosis, monocytopenia, monocytosis, anaemia, and polycythaemia.

Question 5

What are haematopoietic stem cells (HSCs), and what is their role?

Answer 5

HSCs are rare cells in the bone marrow capable of giving rise to all types of blood cells. They undergo self-renewal and can differentiate into mature blood cells.

Question 6

How does differentiation play a role in haematopoiesis?

Answer 6

Differentiation is the process by which immature cells change into mature blood cells with specific functions. It is influenced by epigenetic changes and environmental factors.

Question 7

What are some clinical applications of growth factors in haematopoiesis?

Answer 7

Growth factors like erythropoietin (EPO) and colony-stimulating factors (CSFs) are used to stimulate blood cell production in conditions like anaemia and to mobilise stem cells for transplantation.

Question 8

Explain the significance of the bone marrow in haematopoiesis.

Answer 8

The bone marrow is the primary factory of blood in adults, responsible for producing billions of blood cells daily. It undergoes medullary haematopoiesis.

Question 9

What is extramedullary haematopoiesis, and when does it occur?

Answer 9

Extramedullary haematopoiesis occurs outside the bone marrow and can be physiological (in the fetus) or pathological (in conditions like thalassaemia and myelofibrosis).

Question 10

What are the consequences of defects in the regulation of quiescence in HSCs?

Answer 10

Defects may lead to premature exhaustion of the HSC pool, bone marrow failure, and insufficient blood cell production.

Question 11

Haematopoiesis
Leukopenia
Thrombocytosis
Neutrophilia
Erythropoietin (EPO)
Colony-stimulating factors (CSFs)
Medullary haematopoiesis
Extramedullary haematopoiesis
Haematopoietic stem cells (HSCs)
Differentiation
Growth factors
Quiescence

Answer 11

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Question 12

What is erythropoiesis, and what does it entail?

Answer 12

Erythropoiesis refers to the production of red blood cells (RBCs). It involves the differentiation of hematopoietic stem cells into erythrocytes, which are the main carriers of oxygen in the bloodstream.

Question 13

How long do red blood cells typically survive in circulation, and what happens to them afterward?

Answer 13

Red blood cells survive for approximately 120 days in circulation. After their lifespan, they are removed from circulation by macrophages, primarily in the spleen.

Question 14

What role does erythropoietin (EPO) play in erythropoiesis?

Answer 14

EPO is a hormone produced by the kidneys in response to low oxygen levels. It stimulates the proliferation, differentiation, and maturation of red blood cell precursors in the bone marrow.

Question 15

What is thrombopoiesis, and where does it occur primarily?

Answer 15

thrombopoiesis refers to the production of platelets. It mainly occurs in the bone marrow, where megakaryocytes give rise to platelet precursors.

Question 16

Describe the role of thrombopoietin (TPO) in thrombopoiesis.

Answer 16

Thrombopoietin is a cytokine produced mainly by the liver and kidneys. It binds to thrombopoietin receptors on megakaryocyte progenitors, stimulating the production of megakaryocytes and subsequent platelet formation.

Question 17

Erythropoiesis
Erythropoietin (EPO)
Hemoglobin
Iron, Vitamin B12, Folic Acid
Thrombopoiesis
Thrombopoietin (TPO)
Megakaryocytes
Platelets
Nutrient deficiencies
Stem cell transplantation
Myeloproliferative neoplasms
Aplastic anemia
Leukemia, Lymphoma
Gene therapy

Answer 17

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Question 18

What are the three main contributors to clot formation?

Answer 18

The three main contributors to clot formation are blood vessels and endothelium, platelets, and coagulation factors.

Question 19

what is the central role of the endothelium in clotting?

Answer 19

The endothelium regulates both inflammation and coagulation. Under conditions of stress, it switches from an anticoagulant to a procoagulant phenotype.

Question 20

What are platelets, and what changes occur during platelet aggregation?

Answer 20

Platelets are small subcellular fragments made from megakaryocytes. During aggregation, platelets swell, aggregate, and release granules containing coagulation factors, inflammatory factors, and growth factors.

Question 21

What are the major classes of proteins found in platelet granules?

Answer 21

Platelet granules contain coagulation factors, inflammatory factors, and growth factors.

Question 22

What are the major coagulation factors in the extrinsic, intrinsic, and common pathways of the coagulation cascade?

Answer 22

the major coagulation factors include tissue factor, Factor VII, Factor IX, Factor X, Factor II (prothrombin), and Factor V.

Question 23

What tests can be used to measure the extrinsic, intrinsic, and common pathways of the coagulation cascade?

Answer 23

the extrinsic pathway is measured using a prothrombin time (PT), while the intrinsic pathway is measured using a partial thromboplastin time (PTT). The common pathway can be measured by both PT and PTT.

Question 24

What is the central role of thrombin in coagulation?

Answer 24

Thrombin activates Factor XI, converts soluble fibrinogen to insoluble fibrin, and activates cofactors V and VIII.

Question 25

Name three natural anticoagulants and their targets.

Answer 25

Three natural anticoagulants are antithrombin (targets thrombin), thrombomodulin (targets thrombin), and tissue factor pathway inhibitor (targets tissue factor).

Question 26

What is the major effector of fibrinolysis?

Answer 26

Plasmin is the major effector of fibrinolysis.