blood marie Černá. blood the blood consists of a suspension of special cells - formed elements in...
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BloodBlood
The blood consists of
a suspension of special cells - formed elements
in a liquid called plasma
In an adult man:
the blood is about 1/12th of the body weight
and this corresponds to 5-6 liters
HematocritHematocrit – relation (volume %) – relation (volume %) of plasma (55 %) to cells (45 %) of plasma (55 %) to cells (45 %)
Blood functionsBlood functions• maintenance of homeostasis
osmotic pressure stability (0.15 mM NaCl)pH = 7.4 (buffer system - HCO3
-)
• carries respiratory gases: oxygen O2 to tissues (by the hemoglobin in red cell) carbon dioxide CO2 from tissues (by the plasma
in the form of soluble carbonates HCO3-)
• conveys nutrients (amino acids, sugars, fatty acids) • gathers waste products of metabolism which will be
excreted through the renal filter• carries hormones, enzymes, vitamins, mineral salts• performs the defense of the organism • performs thermoregulation of the organism
PlasmaPlasmais a slightly alkaline fluid, with a typical yellowish color can be obtained by centrifugation cells free serum - clotted
plasma - unclotted due to adding anticoagulants It consists of 90 % water and 10% dry matter:
9/10 is made up by organic substances1/10 is made up by minerals
These organic substances are composed of glucides (glucose)lipids (cholesterol, triglycerides, phospholipids, lecithin, fats)proteins (globulins, albumins, fibrinogen)glycoproteins, amino acids hormones, vitamins, minerals
The mineral substances are dissolved in ionic formthat is dissociated into positive and negative ions
Hematic cellsHematic cells
Special cells • erythrocytes• leukocytes
• thrombocytes
are not considered real cells
Erythrocytes (red cells)Erythrocytes (red cells) providing oxygen in hemoglobin to tissuesproviding oxygen in hemoglobin to tissues
4.5 .106 / mm3 = 4.5 .1012 / l in female
5 . 106 / mm3 = 5 .1012 / l in male
7 . 106 / mm3 = 7 .1012 / l in newborn
8 . 106 / mm3 = 8 .1012 / l in sportsmen
size 7,2 µm in diameter
In man and in all mammals: they are devoid of a nucleus
In the other vertebrates: they have a nucleus
the lack of nucleus allows more room for hemoglobin =>
the shape of a biconcave lens raises the surface and cytoplasm volume ratio.
=> more efficient the diffusion of oxygen
The mean life is about 120 days
Leucocytes (white cells)Leucocytes (white cells) the defense of the organismthe defense of the organism
4-10 .103 / mm3 = 4-10 .109 / l size ≥10 µm in diameter
granulocytes (presence of granules in the cytoplasm) 70% granules have a different affinity towards neutral, acid or basic stains and give the cytoplasm different colors.
neutrophils eosinophils (or acidophils)basophils
agranulocytes (lymphoid cells) 30% lymphocytes (upper slide)monocytes (lower slide)
Thrombocytes (platelets)Thrombocytes (platelets)
150-300 .103 / mm3 = 150-300 .109 / lsize 3µm in diameter
They gemmate from big leukocytes called megakaryocytes.
main function: hematostasisto stop the loss of blood from wounds => they aggregate and release factors which promote the blood coagulation: serotonin - vasoconstriction fibrin - traps cells + forms clotting
Hematopoiesis regulationHematopoiesis regulationin red bone marrowin red bone marrow
ribs, vertebrae, breastbone, pelvisribs, vertebrae, breastbone, pelvis
Erythropoietin Erythropoietin is converted from a plasma protein in the kidneyis converted from a plasma protein in the kidney
a negative-feedback mechanism
- is sensitive to the amont of O2 in the blood:
↓ O2 => ↑ erythropoietin
↑ O2 => ↓ erythropoietin
Erythropoietin
stimulates production of erythrocytes in the bone marrow
Blood clottingBlood clotting
1) Platelet adhesion
2) Platelet plug
3) Fibrin clot with trapped cells
Blood clottingBlood clotting
HemophiliaX-linked disease
missing -
coagulation factor VIII
symptoms:- spontaneous bleeding- bleeding into organs
(join, brain)