Hema lec Flashcards
Begins at 5th – 6th week of gestation
Liver becomes the major hematopoietic organ of early and mid-fetal life
Hepatic stage
Happens during the 4th – 5th Month of Gestation
Bone marrow - main site of cell production
Hemoglobin A (Adult Hemoglobin)
o Consist of 2 alpha & 2 beta
globin chains o Predominant
Medullary stage
Primary site of hematopoiesis
Yolk sac
Day 19 8 weeks’ gestation
o Generates Erythrocytes, Macrophages, Platelets o Primitive Erythrocytes – large Nucleated cells
embryonic hemoglobin
Predominant type of hemoglobin:
Gower 1, Gower 2, Portland
Primitive Hematopoiesis (Blood Islands)
Begins1–2dayslaterthanprimitive hematopoiesis
Definitive erythropoiesis
1st fully developed organ in the fetus
Thymus
low granulocytic production
o Remains active in lymphopoiesis Production of megakaryocytes begins
Spleen
Predominant Type of
Hemoglobin
Hemoglobin F & Hemoglobin A
HEMATOPOIETIC TISSUE LOCATIONS:
- Bone marrow 2. Lymph nodes 3. Spleen
- Liver
- Thymus
BONE MARROW CONTAINS DEVELOPING:
- Erythroid cells
- Myeloid cells
- Megakaryocytic cells
- Lymphoid cells
ADULT HEMATOPOIETIC TISSUE
Lymphoid development occurs in both:
- Primary Lymphoid Tissue
Bone marrow & thymus [where T & B Lymphocytes are derived] - Secondary Lymphoid Tissue
Spleen, lymph nodes & mucosa-associated lymphoid tissue [lymphoid cells responds to foreign antigens]
PRIMARY HEMATOPOIETIC ORGAN AND TISSUE
BONE MARROW
Yellow marrow
Red marrow
Normally inactive
o Composed of fat (adipose) tissue
Yellow marrow
Normally active
o Production of erythrocytes, leukocytes, and
thrombocytes
Red marrow
marrow of all bones are red and
cellular
First few years of life
red marrow vertebrae, ribs, sternum, skull bones, pelvis, proximal epiphyses of femur and humerus
By age of 18
stimulates hematopoiesis
o Primarily produced in the kidneys
Erythropoietin (EPO)
Major function of removing aging and damaged blood cells (e.g., senescent RBC)
Contains the largest collection lymphocytes and macrophages
Pancytopenia
o All blood cells are decreased
o Observed when there is Hypersplenism /
splenomegaly
SPLEEN
ite of lymphocyte proliferation
Filters particulate matter, bacteria or debris that enters the
node via the lymph fluid
Participate in immune response to foreign antigens
LYMPH NODES
Types of immunity
Natural/Innate/Non-specific immunity
Acquired/Adaptive/Specific Immunity
o Active – natural / artificial (Ag) Introduction of antigen
Bodywillproduceantibodyagainstthe antigen
o Passive – natural / artificial (Ab)
Antibodyisintroducedtothebody
Subsets of Lymphocytes
T lymphocytes (T cells)
Blymphocytes(Bcells)
More than 1/3 of the middle
MCHC value is lower than normal
HypochromicRBC
MCHC value is higher than
differentiated in the thymus
Responsible for the production of CD4 / CD8 surface antigen
(markers)
o “T helper cells”
Major function of removing aging and damaged blood cells (e.g., senescent RBC)
Contains the largest collection lymphocytes and macrophages
Pancytopenia
o All blood cells are decreased
o Observed when there is Hypersplenism /
splenomegaly
LYMPH NODES
Site of lymphocyte proliferation
Filters particulate matter, bacteria or debris that enters the
node via the lymph fluid
Participate in immune response to foreign antigens
2 Types of immunity
Natural/Innate/Non-specific immunity
Acquired/Adaptive/Specific Immunity
o Active – natural / artificial (Ag) Introduction of antigen
Bodywillproduceantibodyagainstthe antigen
o Passive – natural / artificial (Ab)
Antibodyisintroducedtothebody
Subsets of Lymphocytes
T lymphocytes (T cells)
normal
Ex. Hereditary Spherocytosis
o Almost no central pallor (spherocytes) o Due to the mutation
to the cytoskeleton marker
Ankyrin
Spectrin o Cannot fold itself to
pass through small blood vessels which may cause clogging
HyperchromicRBC
Needed for the normal Hgb synthesis
Amino acids (proteins)
For Hgb production
Iron
