Week 3 Lec: Hematopoiesis Flashcards
When does hematopoiesis stop?
only after death
It is a continuous, regulated process of blood cell production.
Hematopoiesis
Hematopoiesis is a continuous, regulated process of blood cell production that includes?
- cell renewal
- proliferation
- differentiation
- maturation
What are the two developments of hematopoiesis?
- Pre-natal
- Post-natal
Pre-natal development is also called as?
Embryonic/Fetal Development
Post-natal development is also called as?
Adult Development
3 phases of pre-natal development?
Mesoblastic, Hepatic, and Medullary phase
Other name for mesoblastic phase?
Primitive hematopoiesis/Yolk sac phase
When does the mesoblastic phase begin?
begins around the 19th day of embryonic development after fertilization
Primitive erythrocytes from the mesoblastic phase arise from?
mesodermal cells
The cells from the mesoderm migrate to the _________ and become primitive erythrocytes.
yolk sac
Transient yolk sac erythroblasts are important in early ________ to produce ________ .
embryogenesis; hemoglobin
What are the 3 embryonic hemoglobins that are important in transporting oxygen?
Gower-1, Gower-2, and Portland
What globin chain starts its production at the mesoblastic phase?
Alpha globin chain
Globin chain combination of Gower I?
2 epsilon, 2 zeta
Globin chain combination of Gower II?
2 alpha, 2 epsilon
Globin chain combination of Portland?
2 zeta, 2 gamma
If the globin chain combination has only 1 instead of 2 epsilons, for example, what condition could occur?
Thalassemia
Other name for hepatic phase?
Definitive hematopoiesis
When does hepatic phase begin?
begins at 5 to 7 gestational weeks
The hepatic phase is characterized by?
recognizable clusters of developing erythroblasts, granulocytes, and monocytes colonizing the fetal liver, thymus, spleen, placenta
The developing erythroblasts signal the beginning of __________ with a decline in __________ of the yolk sac.
definitive hematopoiesis; primitive hematopoiesis
Hematopoiesis during hepatic phase occurs __________, with the _____ remaining the major site of hematopoiesis during the second trimester of fetal life.
extravascularly; liver
What type of hemoglobin is present during the hepatic phase?
Hemoglobin F and A
The developing _____,_____,_____, and _____ contribute to the hematopoietic process during hepatic phase.
spleen, kidney, thymus, and lymph nodes
_____, the first fully developed organ in the fetus, is the major site of _____.
Thymus; T cell production
_____ produce B cells during hepatic phase.
Kidney and Spleen
Kidney and Spleen produce _____ during hepatic phase.
B cells
Globin chain combination of Hemoglobin F?
2 alpha, 2 gamma
During the _____ month of fetal development, hematopoiesis begins in the bone marrow cavity.
fifth
During the fifth month of fetal development, hematopoiesis begins in the ________.
bone marrow cavity
Other name for medullary phase?
Myeloid phase
Hematopoietic activity, especially myeloid activity, is apparent during this stage of development, and the myeloid-to-erythroid ratio gradually approaches __________.
3:1 (adult levels)
Measurable levels of _____, _____, _____, _____, and _____ can be detected during medullary phase.
erythropoietin (EPO)
(G-CSF)
(GM-CSF)
hemoglobins F and A
A growth factor stimulating the production of RBC.
Erythropoietin
Where is the source of erythropoietin?
Kidney
They stimulate the production of granulocytes.
G-CSF and GM-CSF
Chief site of the medullary phase?
bone marrow
Globin chain combination of Hemoglobin A?
2 alpha, 2 beta
Globin chain combination of Hemoglobin A2?
2 alpha, 2 delta
What is the degradation product of hemoglobin A?
Hemoglobin A2
In adults, hematopoietic tissue is located in the?
– bone marrow
– lymph nodes
– spleen, liver
– thymus
The bone marrow of adults contain developing?
erythroid, myeloid, megakaryocytic, and lymphoid cells
What do you call the hematopoietic cells responsible for RBCs?
erythroid
What do you call the hematopoietic cells responsible for granulocytes?
myeloid
What do you call the hematopoietic cells responsible for the production of platelets?
megakaryocytic
Lymphoid development occurs in ______ and _____ lymphoid tissue.
primary; secondary
Primary lymphoid tissue is located in?
bone marrow and thymus
This is where T and B lymphocytes are derived.
Thymus
This is where lymphoid cells respond to foreign antigens.
Secondary lymphoid tissue
Secondary lymphoid tissue consists of?
- spleen
- lymph nodes
- mucosa-associated lymphoid tissue
Give the primary locations of bone marrow in adult humans.
Ribs
Sternum, Skull, Scapula
Vertebra
Pelvis
Organs involved in post-natal development?
- Bone marrow
- Liver
- Spleen
- Lymph Nodes
- Thymus
It is one of the largest organs in the body.
Bone Marrow
Major function of bone marrow?
proliferation and production of blood cells
Two major components of Bone Marrow?
Red marrow and Yellow marrow
It is the hematopoietically active marrow consisting of the developing blood cells and their progenitors (flat bones of the skull, clavicle, sternum, ribs, vertebrae and pelvis).
Red marrow
These are “undifferentiated cells”.
progenitors
2 types of progenitors?
common myeloid progenitor and common lymphoid progenitor
4 Main Functions of Red Bone Marrow?
– Production of blood cells
– Destruction of erythrocytes
– Iron storage (from Hb breakdown)
– Central organ for B lymphocyte development