Histo Midterm 2 - Blood Flashcards
What are some basic factoids about the blood?
Made in hematopoetic organs (bone marrow)
Composed of: Erythrocytes, Leukocytes, Plasma, and Thrombocytes (platelets)
Typically between 4-5 liters
What is the hematocrit?
Estimate the volume of RBCs
What are the components of the blood and in what percentages?
Erythrocytes 45%
Leukocytes/Platelets 1%
Plasma 54%
What is the role of plasma?
Transport hormones, nutrients, and waste
What are the plasma proteins?
Albumin
Lipoporteins
Prothrombin, fibrinogen
Alpha, beta, and gamma globulins (immunoglobulins)
Can you describe the structures erythrocyte?
Anucleate biconcave disc, 8 micron diameter, “ghost” of nucleus
33% solution of protein hemogloblin (heme-Iron) (globin-polypetide chain)
What are the subunits contained in each hemoglobin molecule?
2 polypeptides of one type and 2 polypeptides of another
What is the function of the erythrocyte?
Transport oxygen to tissue and returns CO2 back to the lungs
What is the lifespan of RBCs?
120 Days in circulation
What happens to old RBCs?
Gets lodged in the spleen and digested by macrophages
What is Heme recycled to?
Iron - transported to liver for storage
Bilirubin - used in bile
What are the major leukocytes and their percentages from differentials?
Neutrophils - 62%
Easinophils - 3%
Basophils -
What are the granulocytes?
Neutrophils - First line of defense
Easinophils - Phagocytize antigen-antibodies complexes
Basophils - Contain histamine and heparin
What are the agranulocytes?
Monocytes - Become tissue macrophage
Lymphocytes - Only WBC to return from the tissue into the blood
What are the platelets?
First step in coagulation (pieces of RBCs)
Contain a granulomere (Dark part) and hyalomere (clear part)
What is the embryonic timeline and location for hematopoeisis?
1st trimester - 3rd week of gestation in the yolk sac mesoderm
2nd trimester - Liver is major blood forming organ, then spleen
How is hematopoeisis accomplished after birth?
Blood is produced in bone marrow, which give rise to different family trees for each blood cell type
What is unique about stem cells?
The are pluripotential and can self renew
What is the bone marrow and how does it change?
Red Marrow - found in younger patients
-Stroma: collagen type II & III; fibroconectin
-Hematopoeisis cord: cell families & macrophages
-Sinusoid capillaries: discontinuous endothelium
Yellow Marrow - found in older patients
-Large amounts of adipose
Can you explain the changes that occur as the hemocytoblast differentiates into the RBC?
Erythropoeisis
Cell volume decreases -> Nucleoli diminish -> Nuclear diameter decreass -> Chromatin become more dense -> Cytoplasm turns acidophilic -> Nucleus is excluded
What are the specific cell types and features in erythropoeisis?
Hemocytoblast -> Proerythroblast -> Basophilic erythroblast -> Polychromatophilic erythroblast -> Orthochromatophilic erythroblast -> Reticulocyte -> Mature Erythrocyte
Explain the changes that occur in granulopoeisis?
Myeloblast -> Promyelocyte -> Myelocyte (Special granules: Neutrophilic, Eosinophilic, Basophilic), Mature: Neutrophil, Eosinophil, and Basophil
What changes occur in the agranulocyte lymphopoesis?
Bone marrow ->Lymphoblast -> Prolymphocyte -> Lymphocyte
What changes occur in the agranulocyte Monopoeisis?
Monoblast -> Promonocyte -> Monocyte (circulates for 8hrs)-> Macrophage when enters CT
