Hematologic System: A Review

These flashcards cover key aspects of the hematologic system, including blood composition, hematopoiesis, regulation of erythropoiesis, hemoglobin structure, hemostasis, and relevant laboratory tests.

What are the main components of blood composition?

Plasma, buffy coat (platelets and leukocytes), and formed elements (erythrocytes).

What is erythropoiesis?

The formation of red blood cells (RBCs) that occurs in the bone marrow.

What is the average blood volume in adults?

5-6 liters.

What role do plasma proteins serve?

They serve important roles as enzymes, antibodies, and transport carriers of other compounds throughout the body.

Where does hematopoiesis primarily occur after birth?

In the bone marrow.

What is the life span of a red blood cell?

Approximately 120 days.

What vitamin is essential for the absorption of vitamin B12?

Intrinsic factor.

What is the function of erythropoietin?

Stimulates the production of red blood cells in response to low oxygen levels.

What are the components of hemoglobin?

Two pairs of polypeptide chains (globins) and an attached heme molecule containing iron.

What triggers the formation of a blood clot during hemostasis?

Activation of the clotting cascade and formation of a platelet plug.

What is the process of dissolving a clot called?

Fibrinolysis.

What are the natural anticoagulants mentioned?

Antithrombin III, Proteins C and S, and Tissue factor pathway inhibitor.

What do prothrombin time (PT) and partial thromboplastin time (PTT) tests assess?

PT assesses function of the extrinsic pathway, while PTT assesses function of the intrinsic pathway.