3. Hematopoiesis conclusion

What is hematopoiesis?

The process of blood cell production.

Where does intramedullary hematopoiesis occur?

Within the bone marrow.

What is extramedullary hematopoiesis?

Hematopoiesis occurring outside the bone marrow, mainly in the liver and spleen.

In adults, where does extramedullary hematopoiesis primarily occur?

In the liver and spleen.

What condition can occur due to extramedullary hematopoiesis?

Hepatosplenomegaly.

What does the spleen filter?

Blood.

What are the two types of pulp found in the spleen?

Red pulp and white pulp.

What is the primary function of the red pulp in the spleen?

Red blood cell filtration.

What organ serves as a secondary hematopoietic organ?

The spleen.

At what age does the spleen begin hematopoiesis?

At 2-3 months.

What happens to hematopoiesis in the spleen at birth?

It ceases and becomes exclusively bone marrow.

What happens to malformed red blood cells in the spleen?

They are removed.

What immunological role does the spleen play?

Promotes phagocytic activity.

What is the largest secondary lymphoid organ?

The spleen.

Which types of organisms does the spleen target through phagocytosis?

Encapsulated organisms like Haemophilus influenzae and Streptococcus pneumoniae.

What are opsonizing antibodies?

Substances that strip the capsule from bacterial surfaces.

What is splenectomy?

Surgical removal of the spleen.

What happens to the liver's role if the spleen is removed?

The liver takes over some of the spleen's functions.

What are Howell-Jolly bodies?

DNA remnants in red blood cells, appearing as round bodies.

What does the myeloid:erythroid (M:E) ratio indicate?

The proportion of myeloid and erythroid cells in the bone marrow.

Is the myeloid:erythroid (M:E) ratio higher in infection or normal state?

Higher in infection.

What is the normal M:E ratio?

Between 2:1 to 4:1.

What could an increased M:E ratio indicate?

Conditions like infection or Chronic Myeloid Leukemia (CML).

What does decreased leukopoiesis indicate?

Less production of leukocytes.

What condition results in erythroid hyperplasia?

Hemolytic anemia.

What is polycythemia vera?

A condition of increased red blood cell production.

What can lead to changes in the M:E ratio?

Factors that impair red blood cell lifespan or production.

What is erythropoietin (EPO)?

A hormone that stimulates red blood cell production.

How does the bone marrow respond to anemia?

It increases production 6-8 times.

What is released by the kidney in response to tissue hypoxia?

Erythropoietin (EPO).

What are reticulocytes?

Immature red blood cells released into circulation.

What is polychromasia?

Presence of reticulocytes in circulation.

What is the function of megakaryocytes?

Production of platelets.

What are the three main types of cells produced in the bone marrow?

Red blood cells, white blood cells, and platelets.

How much does the adult bone marrow weigh?

About 1500 grams.

What is the significance of the yellow marrow?

Represents adipose tissue and storage.

What is the primary function of the spleen regarding white blood cells?

Processing and storage.

Which organ can take over for the spleen when it is removed?

The liver.

What type of anemia results from the bone marrow trying to replace destroyed red blood cells?

Hemolytic anemia.

What conditions can cause myeloid hypoplasia?

Diminished white blood cell production.

What is the impact of an anemic event on red blood cell maturation?

Cells are released more immature than usual.

In what state is the erythroid ratio increased?

During conditions like hemolytic anemia.

What happens if the spleen sees 'ugly' red cells?

It removes them from circulation.

What is the role of the marginal zone in the spleen?

Stores white blood cells and platelets.

What can alterations in the M:E ratio indicate?

Hematologic pathology.

What are encapsulated organisms?

Bacteria with a protective outer layer that can be targeted by the spleen.

What significance does being a secondary hematopoietic organ hold for the spleen?

It plays a crucial role in immune function and blood cell production.

How does the spleen contribute to opsonization?

By producing antibodies that help in the phagocytosis of pathogens.