MLS1114 Exam 2

Define Hematopoiesis

The process of maintain an adequate supply of red blood cells

Define homeostasis

A ballance between cellular proliferation, differentiation, and apoptosis

Define apoptosis

Preprogrammed cell death

What is apoptosis role in the cell lifecycle

Helps eliminate excess cells, old, abnormal, or infected cells

can be induced by other cells

Define necrosis

A cell that is dying by non-natural means (ie: burn your arm)

Where does definitive erythropoiesis occur

Primarily in the bone marrow after birth, and in the yolk sac, liver, and spleen during embryonic development.

The formation of what cell indicates definitive erythropoiesis?

Where does hematopoiesis happen during 18 days gestation?

Requires oxygen from mom, fetal hemoglobin

Where does hematopoiesis happen during childhood?

In the bone marrow, all bone marrow is active red marrow

Where does hematopoiesis happen during adulthood?

End of long bones, pelvis, skull, ribs, sternum, scapula, vertebrae, clavicles

Define primitive erythropoiesis

The process of blood cell formation occurring in the yolk sac during early embryonic development, primarily producing primitive red blood cells.

Define definitive erythropoiesis

the process of forming red blood cells from definitive erythroid progenitors, primarily occurring in the bone marrow during fetal development and after birth.

Define medullary hematopoiesis

Hematopoiesis in the bone marrow

Define extramedullary hematopoiesis

Hematopoiesis outside of the bone marrow

What is the difference between medullary and extra medullary hematopoiesis?

Medullary hematopoiesis occurs in the bone marrow, while extramedullary hematopoiesis takes place outside the bone marrow, often in organs like the spleen or liver.

What are the common sites of extramedullary hematopoiesis?

What is the only cell that can divide?

lymphocytes

How many RBCs per day do you make?

200 billion

How many WBCs and plts do you make per day?

100 billion

Where does hematopoiesis happen at 3 months gestation

Primarily the liver, also activity in the kidneys and lymphoid tissue

Where does hematopoiesis happen at 6 months gestation?

Shifts from organs to bone marrow

Define bone marrow hyperplasia

An increase in the production of blood cells in the bone marrow, often in response to increased demand or underlying conditions.

Describe the composition of bone marrow

Define the hematopoietic environment

What are the three main stromal cells?

Macrophages

Adipocytes

Fibroblasts

Define osteiblast

Define osteoclast

Define hyperplastic bone marrow

What causes hyperplastic bone marrow?

Define hypoplastic bone marrow

What causes hypoplastic bone marrow

What are the primary lymphoid organs?

The primary lymphoid organs are the bone marrow and thymus, where lymphocytes are produced and mature. No antigen activity

What are the secondary lymphoid organs?

Spleen, lymph nodes. Antigen dependent lymphopoiesis

What type of lymphocytes does the bone marrow make?

B cells

What type of lymphocytes does the thymus make?

T cells

What does the thymus do in hematopoiesis

The thymus plays a crucial role in hematopoiesis by maturing T cells, which are essential for adaptive immunity. Antigen dependent, well defined in children but atrophied in adults

What does the spleen do?

How does the spleen stress RBCs?

Define differentiation

Define commitment

Define maturation

Define culling

Define pitting

What three things are needed to diagnose hypersplenism

Define splenomegaly

What conditions cause splenomegaly

List the maturation of RBCs in order with old nomenclature

List the maturation of RBCs in order with new nomenclature

What’s the role of cytokines in cell maturation and differentiation

Whats the role