1. BLOOD, BLOOD CELLS Semmelweis University, Faculty of Medicine
1st year, 1st semester
Department of Human Morphology and Developmental Biology
Katalin Kocsis
11/11/2013
12/11/2013

2. Blood performs many important functions within the body including:
Supply of oxygen to tissues (bound to hemoglobin, which is carried in red cells)
Supply of nutrients such as glucose, amino acids, and fatty acids (dissolved in the blood or bound to plasma proteins (e.g., blood lipids))
Removal of waste such as carbon dioxide, urea, and lactic acid
Immunological functions, including circulation of white blood cells, and detection of foreign material by antibodies
Coagulation, which is one part of the body's self-repair mechanism (blood clotting after an open wound in order to stop bleeding)
Messenger functions, including the transport of hormones and the signaling of tissue damage
Regulation of body pH
Regulation of core body temperature

3. Development of the circulatory system

4. with the formation of hemangioblastic aggregates.
Hematopoiesis and blood vessel formation first begins within the yolk sac wall
with the formation of hemangioblastic aggregates.
Figure 13-1 A, Drawing illustrating the formation of hemangioblastic aggregates and their differentiation into hematopoietic stem cells and endothelial precursor cells within blood islands. Blood islands subsequently form both endothelial cells and primitive erythrocytes. B, Expression of Vegfr2 mRNA, an early marker for hemangioblastic aggregates, within the yolk sac wall of a 15-somite avian embryo. As the blood islands develop, endothelial cells retain Vegfr2 expression, whereas hematopoietic stem cells progressively lose it.

5. The arterial clusters
Figure 13-3 A second source of hematopoietic stem cells arises within the splanchnic mesoderm surrounding the aortic, gonad, and mesonephric region (AGM). These cells temporarily reside in the ventral floor of the dorsal aortic of this region. A, In humans at about day 27, a small number of hematopoietic stem cells (in red) reside and adhere to the dorsal aorta near the origin of the vitelline artery in the umbilical region. B, By day 30, the number of hematopoietic stem cells expands to several thousand. C, By day 36, hematopoietic stem cells expand to reside in the ventral floor of the dorsal aorta along almost the entire length of the AGM, and extending into the vitelline artery. By day 40, hematopoietic stem cells are no longer detected in the dorsal aorta.

6. Current hypothesis about the colonisation of hematopoietic organs during embryonic development
Figure 13-2 Timeline of the appearance of hematopoietic stem cells during human development.

7. Figure 6-16 Hematopoietic hierarchy7

8. Composition of blood CELLULAR PLASMA COMPONENTS -55 % of the blood
Red blood cells
(erythrocytes)
-99% of the cells
-oxygen and carbon dioxide
transport
White blood cells
(leukocytes)
-defence of the organism
Platelets
(thrombocytes)
- blood clotting
PLASMA
-55 % of the blood
-water
-electrolytes
-proteins
albumin
fibrinogen
globulins
-transported molecules
(mostly transported
bound to proteins)
nutrients, vitamins,
trace elements
metabolic products
hormones
fatty substances 8

9. Difference between plasma and serum

10. 10

12. Formed elements 12

13. Blood smear and May-Grünwald Giemsa staining
to study the morphology of blood cells
one drop of blood

14. Cells in the blood smear
erythrocytes
platelets
monocyte
eosinophil neutrophil basophil
granulocytes
small medium
lymphocyte
neutrophil
granulocyte

15. Red blood cells
(erythrocytes)

16. 16

17. Red blood cells (erythrocytes)
-no cell nucleus
-disk-shaped, concave on both sides, (special cytoskeleton with spektrin molecules)
Function:
O2 and CO2 transport
lifespan: 120 days, broken down in the spleen and in the liver (iron: stored, reused) 17

18. Figure 6-2 Cell membrane of a red blood cell

19. Platelets
(thrombocytes)

20. Platelets (thrombocytes)
-citoplasm fragments which derives from megakaryocytes (giant cells in the bone marrow)
-lifespan: 5-10 days
/ml
2-3 µm
Function:
blood clotting 20

21. Megakaryocyte in the bone marrow

22. Cell biology of platelets

23. Blood clotting or hemostasis

24. White blood cells
(leukocytes)

25. White blood cells (leukocytes) Granulocytes Agranulocytes
relatively colorless cells
Granulocytes
(polymorphonuclear leukocytes)
neutrophils (neutrophil granulocytes)
eosinophils (eosinophil granulocytes)
basophils (basophil granulocytes)
Agranulocytes
lymphocytes
monocytes
Their lifespan varies, can be from a few hours to years. Together with the lymphoid organs the white cells form the immune system.

26. (Polimorphonuclear leukocytes)
Granulocytes
(Polimorphonuclear leukocytes)

27. Neutrophil granulocyte
-size: µm
-segmented nucleus (3-5 lobes)
-small granules in the citoplasm
60-70% of white blood cells
also called phagocytes (microphage) because they phagocytose foreign material (first cells to reach the site of an inflammation)
part of the nonspecific immune system 27

30. Eosinophil granulocyte
-size: µm;
-two-lobed nucleus
-eozinophilic granules containing histamin, crystals can be detected by EM
-1-6% of white blood cells
-are capable of phagocytosis (Ag-Ab complexes), in allergic reactions they bound to and inactivate excess histamine (from mast cells or basophils) 30

31. Basophil granulocyte -size: 10-15 µm
segmented nucleus (not seen because of the granules)
many, large, basophil cytoplasmic granules (heparin, histamine).
0-1% of white blood cells
effector cells in allergy, immediate hypersensitivity 31

33. Comparison of granulocytes33

34. (Mononuclear leukocytes)
Agranulocytes
(Mononuclear leukocytes)

35. Monocytes -size: 15-20 µm (largest WBC!)
-ovale or kidney-shaped nucleus, numerous lysosomes in the cytoplasm
-precursors of tissue macrophages
2-6 % of white blood cells
Function:
coordination of cellular and humoral immune response 35

37. Lymphocytes -size: 8-10 µm
-round-shaped nucleus, organellum rich citoplasm
% of white blood cells
Functions:
cells of the specific (humoral and cellular) immunity
Subtypes:
B- and T-lymphocytes
NK cells (against tumor cells)
activated lymphocytes increase their cytoplasm and rER 37

39. Summary of main functions of blood cells

40. Laboratory data
Complete blood count

41. 41

42. number of different blood cells in the peripheral blood of normal adults:
erythrocytes (red blood cells): x106/mm3 (µl) or 4-5 T(1012)/l,
leukocytes (white blood cells): x103/mm3 (µl) or 6-10 G(109)/l,
thrombocytes (platelets): x103/mm3 (µl) or T(1012)/l
differential count of the blood (ratio of the different white blood cells):
neutrophils (Neu): %
stab (St): 1-2 %
basophils (Bas): 0.5 %
eosinophils (Eo): 2-3 %
lymphocytes (Ly): %
monocytes (Mo): 3-8 %
hemoglobin (concentration of hemoglobin): g /100 ml
hematocrit (ratio of red blood cells): %

44. Laboratory data
Blood groups

45. AB0 antigen Rh antigen (D antigen) + / - Phenotype Genotype A AA or AO
BB or BO AB O OO
Rh antigen (D antigen)
+ / -
Population
Rh(D) Neg
Rh(D) Pos
Basque people
21–36%[13]
65%
other Europeans
16%
84%
African American
approx 7%
93%
Native Americans
approx 1%
99%
African descent
less 1%
over 99%
Asian

46. References:
The human body, Thieme
Kierszenbaum: Histology and Cell Biology, Elsevier
Alberts et al.: Molecular biology of the cell
Lodish et al.: Molecular cell biology