1304- Hematopoeisis conclusion (3)

hepatosplenomegaly

enlargement of the liver and spleen

Extramedullary hematopoiesis occurs where?

OUTside the bone marrow (would be liver/spleen in adults, BUT that strains those organs)

Intramedullary hematopoiesis occurs where?

IN the bone marrow

The spleen is a primary OR secondary hematopoietic organ?

Secondary

Where is the spleen?

Left side of body under rib cage

What does the spleen do?

Filters blood and produces RBCs, WBCs, and platelets as needed

What 3 areas (?) are in the spleen?

White pulp

Red pulp

Marginal zone

Marginal zone does what?

stores WBCs and platelets

Red vs white pulps function?

Red: RBC filtration

White: lymphocyte processing

As the largest secondary lymphoid organ, what is the spleen immunologic role?

Promotes phagocytic activity for encapsulated organisms by producing opsonizing antibodies

What do opsonizing antibodies do?

They strip the capsule from the bacterial surface

Why would one need a splenectomy?

It isnt functioning/is damaged + is a danger to the patient

The liver does not take over some of the spleens functions after the spleen is removed. T or F

FALSE, it does

What conditions might lead to an enlarged spleen?

Leukemic conditions

M:E ratio stands for

myeloid-erythroid ratio

When is the M:E ratio increased?

Infection

Erythroid hypoplasia

Chronic myelogenous leukemia

When is the M:E ratio decreased?

Leukopoeisis

Erythroid anemia

Myeloid hypoplasia

Causes of erythroid hyperplasia (RBC increase)?

Hemolytic anemia

Polycythemia vera

Megaloblastic anemia

Polycythemia vera means?

Increased RBC production

Megaloblastic anemia means?

hyperactive marrow

Myeloid hypoplasia means?

Diminished WBCs

Hemolytic anemia means?

BM tries to replace destroyed EBCs at a frantic pace

BM

bone marrow

In the case of an anemic event, what does the bone marrow do?

Expand production by 6-8x so cells are put into production sooner (but younger)

How much of our body weight is BM?

3-6% of adult body weight (so 1500g)

What is bone marrow composed of?

Yellow marrow

Red marrow

Nutrients

Blood vessels

What kind of cells are in bone marrow?

erythroid cells (RBC), myeloid cells (WBC), and megakaryocytes (platelets) in various stages of maturation + osteoclasts, stroma, fatty tissue

What happens when once cells have matured in the bone marrow?

They pass through the sinuses in the marrow to enter peripheral circulaton

What is the M:E ratio about?

Gives an approx. of myeloid to erythroid elements in the marrow (which includes their precursor cells)

What is a normal M:E ratio?

2:1 to 4:1

What are good indicators of hematologic pathology?

whatever affects RBC lifespan OR causes dramatic increase in a certain cell line (affecting M:E ratio)

When does the spleen begin and end hematopoiesis?

Begins hematopoeisis at 2-3 months like the liver and ceases at birth

bone marrow does the work exclusively now unless required