Histo Midterm 2 - Blood

Question 1

What are some basic factoids about the blood?

Answer 1

Made in hematopoetic organs (bone marrow)
Composed of: Erythrocytes, Leukocytes, Plasma, and Thrombocytes (platelets)
Typically between 4-5 liters

Question 2

What is the hematocrit?

Answer 2

Estimate the volume of RBCs

Question 3

What are the components of the blood and in what percentages?

Answer 3

Erythrocytes 45%
Leukocytes/Platelets 1%
Plasma 54%

Question 4

What is the role of plasma?

Answer 4

Transport hormones, nutrients, and waste

Question 5

What are the plasma proteins?

Answer 5

Albumin
Lipoporteins
Prothrombin, fibrinogen
Alpha, beta, and gamma globulins (immunoglobulins)

Question 6

Can you describe the structures erythrocyte?

Answer 6

Anucleate biconcave disc, 8 micron diameter, “ghost” of nucleus
33% solution of protein hemogloblin (heme-Iron) (globin-polypetide chain)

Question 7

What are the subunits contained in each hemoglobin molecule?

Answer 7

2 polypeptides of one type and 2 polypeptides of another

Question 8

What is the function of the erythrocyte?

Answer 8

Transport oxygen to tissue and returns CO2 back to the lungs

Question 9

What is the lifespan of RBCs?

Answer 9

120 Days in circulation

Question 10

What happens to old RBCs?

Answer 10

Gets lodged in the spleen and digested by macrophages

Question 11

What is Heme recycled to?

Answer 11

Iron - transported to liver for storage

Bilirubin - used in bile

Question 12

What are the major leukocytes and their percentages from differentials?

Answer 12

Neutrophils - 62%
Easinophils - 3%
Basophils -

Question 13

What are the granulocytes?

Answer 13

Neutrophils - First line of defense
Easinophils - Phagocytize antigen-antibodies complexes
Basophils - Contain histamine and heparin

Question 14

What are the agranulocytes?

Answer 14

Monocytes - Become tissue macrophage

Lymphocytes - Only WBC to return from the tissue into the blood

Question 15

What are the platelets?

Answer 15

First step in coagulation (pieces of RBCs)

Contain a granulomere (Dark part) and hyalomere (clear part)

Question 16

What is the embryonic timeline and location for hematopoeisis?

Answer 16

1st trimester - 3rd week of gestation in the yolk sac mesoderm
2nd trimester - Liver is major blood forming organ, then spleen

Question 17

How is hematopoeisis accomplished after birth?

Answer 17

Blood is produced in bone marrow, which give rise to different family trees for each blood cell type

Question 18

What is unique about stem cells?

Answer 18

The are pluripotential and can self renew

Question 19

What is the bone marrow and how does it change?

Answer 19

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

Question 20

Can you explain the changes that occur as the hemocytoblast differentiates into the RBC?

Answer 20

Erythropoeisis
Cell volume decreases -> Nucleoli diminish -> Nuclear diameter decreass -> Chromatin become more dense -> Cytoplasm turns acidophilic -> Nucleus is excluded

Question 21

What are the specific cell types and features in erythropoeisis?

Answer 21

Hemocytoblast -> Proerythroblast -> Basophilic erythroblast -> Polychromatophilic erythroblast -> Orthochromatophilic erythroblast -> Reticulocyte -> Mature Erythrocyte

Question 22

Explain the changes that occur in granulopoeisis?

Answer 22

Myeloblast -> Promyelocyte -> Myelocyte (Special granules: Neutrophilic, Eosinophilic, Basophilic), Mature: Neutrophil, Eosinophil, and Basophil

Question 23

What changes occur in the agranulocyte lymphopoesis?

Answer 23

Bone marrow ->Lymphoblast -> Prolymphocyte -> Lymphocyte

Question 24

What changes occur in the agranulocyte Monopoeisis?

Answer 24

Monoblast -> Promonocyte -> Monocyte (circulates for 8hrs)-> Macrophage when enters CT

Question 25

How do platelets arise?

Answer 25

Megakaryoblast -> Magakaryocyte -> Platelets (thrombocytes)

Question 26

Is blood considered CT?

Answer 26

Yes