Week 6 Blood and Hematopoieses Part 3 Flashcards
**Examples of granulocytes?
Neutrophiles, eosinophils, basophils
**Examples of agranulocytes?
Lymphocytes, Thrombocytes, and monocytes (can differentiate into macrophages in tissue)
Myeloblast
1st neutrophil precursor, nucleus occupies most of cell, chromosomes evenly distributed, nucleoli present, cytoplasm is blue and smooth
Promyelocyte
2nd neutrophil precursor, can now see Azurophilic granules, large round nucleus still
Neutrophilic Myelocyte
3rd neutrophil precursor, has the full complement of specific granules (primary, secondary, tertiary), elliptical nucleus with coarse chromatin
Neutrophilic Metamyelcyte
4th neutrophil precurser, indented nucleus, chromosomes are more heteromatic
Band cell
5th neutrophil precurser, nucleus is elongated and has U shape, FINAL STAGE before neutrophil can leave bone marrow, may be seen circulating blood during early stages of infection
List the stages of neutrophilic development in bone marrow?
Myeloblast, promyelocyte, neutrophilic myelocyte, neutrophilic metamyecyte, band cell
What is hematopoiesis?
the production of red/white blood cells and platelets, which occurs in the bone marrow
Explain the lifespan of blood cells
Finite. Continually destroyed and most be repaired
What is the average lifespan for erythrocytes, platelets, and leukocytes?
Erythrocytes= 120 days/4 months; platelets= 10 days; leukocytes=variable
Where does hematopoiesis take place in the adult?
Formed in and around the spongy red one marrow, typically in long bones
What is all formed in red bone marrow?
Erythrocytes, granulocytes, monocytes, platelets
What is all formed in red bone marrow and lymphatic tissues?
Lymphocytes
What cell is formed in two places?
Lymphocytes (red bone marrow and lymphatic tissue-thymus and spleen)
What is the monophyletic theory of hematopoiesis?
All blood cells arise from a common stem cell
Hematopoietic stem cells can differentiate into?
Can differentiate into all the blood cell types. Is a SELF RENEWING cell population. Can differentiate into non-blood cell lineages under certain conditions like injury or organ failure
Hematopoietic stem cells can differenciate into?
All blood cell types AND non-blood cell types in extreme cases
First two main branches of hematopoietic stem cell?
Common lymphoid progenitor and common myeloid progenitor
What is red bone marrow?
Loose collection of progenitor cells in long bone, ACTIVE, consists of blood vessels. Specialized blood vessel units (sinusoids) and the spongy network of hematopoietic cells
What are sinusoids? Function?
Basically capillaries where arteries and veins come together to release new blood, semipermeable, act like a barrier to keep circulation FROM the differentiating compartment of progenitor cells
Sinusoids found where?
In red bone marrow in long bones
Sinusoid wall is lined by?
Endothelial cells (simple squamous)
Sinusoid wall is?
Incomplete, to allow migration of hematopietic cells
Differentiating cells tend to clump together as?
Little islands close to sinusoids
What allows differentiated cells to reach blood stream?
The loose connection of cells around sinusoids is what allows differentiated cells to reach circulation
Don’t think of yellow bone marrow as inactive, think of it as?
Suppressed, bc it can be triggered to make blood
Yellow bone marrow
No longer hematopoietically active, found in long bones of arms/fingers/legs/toes where red bone marrow has been replaced by adipose tissue
Yellow bone marrow retains ___________ potential and can be reverted to?
Retains hematopoeietic potential and can be reverted to red bone marrow under conditions of severe blood loss
How are bone marrow examinations performed?
By a needle biopsy
