Transcript 01 Physiology of red blood cells. Erythron. Respiratory pigments

Physiology of red blood cells.
Erythron.
Respiratory pigments
Blood system
 Blood
system firstly was proposed by
Lung in 1936.
 It consist of
 - blood circulated through the blood
circulatory system
 - blood forming organs
 - blood destroying organs
 - regulatory apparatus.
Blood
Blood is a fluid connective tissue.
 Blood consist of
 - plasma
 - blood cells:
1. erythrocytes,
2. leucocytes,
3. platelets.
Function of blood
Functions of blood
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1. Breathing function of blood.
 2. Trophic function of blood.
 3. Excretory function of blood.
 4. Hormonal regulation.
 6. Temperature regulation.
 7. Maintaining the acid-base balance of tissues.
 8. Supporting the water-electrolytic balance.
 9. Homeostasis function.
 10. Protecting the body from bacteria and other
organisms that can cause diseases or other abnormal
conditions.
Functions of Blood
 Transport
of:
– Gases, nutrients, waste products
– Processed molecules
– Regulatory molecules
 Regulation of pH and osmosis
 Maintenance of body temperature
 Protection against foreign substances
 Clot formation
Production of Erythrocytes:
Erythropoiesis
Quantity (volume) of blood, the
concept of its deposit
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In adult in normal blood, relative to total body
weight, is 6.8%. Newborns - 15%.
Part of the blood is in the depot:
liver - 20%, in the skin, subcutaneous vascular
plexus - up to 10%, in the spleen - up to 1.52% of blood.
 Deposited blood in comparison with blood
circulating in the vessels is 10-20 times slower
than blood cells.
.
Human blood smear
X 500
Quantity of cells, their changing
Erythrocytes
In men – 4,0-5,1 Tera/L; in women –
3,7-4,7 Tera/L.
The quantity of erythrocytes may be
increase – in pregnancy, in physical
training, mental work, in newborn or
decrease.
Leukocytes - 4-9 Giga/L.
The number of leukocytes can increase
– physical work, emotional load, in
newborn, inflammation or decrease.
Platelates - 180-320 Giga/L.
Blood cells
Plasma
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Water – 90 %
Solids – 10 %
Inorganic chemicals:
sodium, calcium, potassium, magnesium, chloride,
bicarbonate, phosphate, sulfate – 0,9 %
Organic chemicals:
Proteins: serum albumin, serum globulin, fibrinogen – 8 %
Others: – 1,1 %
Nonprotein nitrogenous substances: urea, uric acid, creatine,
creatinine, ammonium salts, amino acids
Nonnitrogenous substances: glucose, fats, cholesterol
hormones
Gases: oxygen, carbon dioxide, nitrogen
Components of Whole Blood
Plasma
(55% of whole blood)
Buffy coat:
leukocyctes and
platelets
(<1% of whole blood)
1 Withdraw blood
2 Centrifuge
and place in tube
• Hematocrit
• Males: 40-48%
• Females: 36- 42%
Erythrocytes
(45% of whole blood)
Formed
elements
Proteins
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One liter of plasma has 65-85 gram of proteins.
 Concentration of
 albumins is 35-50 g/L;
 globulins is alpha-1-globulins – 1-4 g/L,
 alpha-2-globulins – 4-8 g/L,
 beta-globulins – 6-12 g/L,
 gamma-globulins – 8-16 g/L;
 fibrinogen – 2-4 g/L.
 Plasma which are not contain fibrinogen called
serum (it is necessary for understanding the
immunology, therapy etc.)
Functional significance of plasma
proteins
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Albumin: 80% defines oncotic pressure transfer bilirubin,
urobilin , fatty acids , antibiotics , sulfonamides , are formed in
the liver , 17 g per day.
Globulin. In a fraction of α1- globulins are proteins associated
with carbohydrates. The fraction of α2- globulins include
protein ceruloplasmin, thyroxine binding protein , vitamin B12
-binding globulin , angiotensin . By β- globulins include
transfer of lipids, polysaccharides and iron.
Antibodies are mainly γ- globulins. Globulins are synthesized
in the liver , bone marrow , spleen and lymph nodes. By day 5
grams of globulin synthesized
Fibrinogen . (2-4 g / L) takes part in the formation of a blood
clot . Formed exclusively in the liver.
Buffer systems of blood
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Maintaining a constant acid-base balance of
blood provided by buffer systems:
1. Bicarbonate buffer:
Н2СО3 + ОН– ⇄ НСО3– + Н2О,
НСО3– + Н+ ⇄ Н2СО3
2. Phosphate buffer:
Н2РО4– + ОН– ⇄ НРО42– + Н2О,
НРО42– + Н+ ⇄ Н2О4–
3. The protein buffer:
RСООН + ОН– ⇄ RООС– + Н2О,
RСОО– + Н+ ⇄ RООН
4. Hemoglobin buffer. Essentially, there are two
hemoglobin buffers - one based on reduced
hemoglobin: NNb/Nb- and the other based on
oxyhemoglobin: NHbO2/HbO2. First prevails in the
venous blood, and the second - in the arterial:
НHb + ОН– ⇄ Нb– + Н2О;
НHbО2 + ОН– ⇄ НbО2– + Н2О,
Нb– + Н+ ⇄ ННb;
НbО2– + Н+ ⇄ ННbО2
Evaluation of acid-base balance is
performed on the following parameters:
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1. pH (from Eng. power Hydrogen - the power of hydrogen),
which is equal to 7,35-7,45.
2. Tension of CO2 - pCO2, which is normally 5,3-6,1 kPa (4046 mm Hg).
3. Standard bicarbonate, international designation SB (standart
bikarbonate) - estimated. At standard conditions is 20-27 mg /
dL.
4. True, actual bicarbonate, international designation AB
(actual bikarbonate), is 190-25 mg / dL.
5. Excess (deficiency) framework, international designation
CE (D) (base ecxess (deficit) equals ± 2,3 mmol / l.
6. The sum of the bases of all the blood buffer systems,
international designation BB (batter bases) is 40-60 mg / dL.
Destruction of red blood cells
The destruction of hemoglobin
EXCHANGE IRON IN THE
BODY
The basic amount of iron
in the body (57.6%) is
part of hemoglobin in red
blood cells and is found.
 Iron enters the body in
the food (meat, liver,
fish, rice, peas, raisins,
apricots). It is best
absorbed iron, which is
part of the food in the
form of heme.
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The functions of red blood cells
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Transport function. Red
blood cells carry: O2,
CO2, NO, adsorbed
proteins, drugs,
physiologically active
substances.
Provide acid-base
balance.
Maintaining the ionic
composition of the
plasma.
Hemostatic.
The structure of erythrocyte
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Human erythrocytes nuclear-cells that are
shaped like concave
discs 4,5-10,5
microns in diameter
(average diameter of
erythrocyte 7,55 m).
With this form of
erythrocyte, its
surface is greater
than it would be in
spherical form.
Scheme of hematopoiesis
Mechanisms regulation of
erythropoiesis
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Regulation of erythropoiesis carried out by neural and humoral
mechanisms, sympathetic innervation stimulates
hematopoiesis and parasympathetic - brakes.
Of great importance is the regulation of erythropoiesis
erythropoietin. Hematopoiesis is enhanced by hormones front
of the pituitary gland, adrenal glands, thyroid gland. Male sex
hormones stimulate, increasing the sensitivity of bone marrow
to erythropoietin, and women - inhibit erythropoiesis.
The body formed substances that inhibit erythropoiesis inhibitors of erythropoiesis. Their content increases with the
number of red blood cells, which do not meet the needs of the
tissues for oxygen. Inhibitors of erythropoiesis lengthen cycle
division erythroid cells, they inhibit the synthesis of
hemoglobin.
Regulation and Requirements for
Erythropoiesis
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Circulating erythrocytes – the number remains
constant and reflects a balance between RBC
production and destruction
– Too few red blood cells leads to tissue hypoxia
– Too many red blood cells causes undesirable blood
viscosity
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Erythropoiesis is hormonally controlled and
depends on adequate supplies of iron, amino
acids, and B vitamins
Regulation of erythropoiesis
Respiratory pigments
 Hemoglobin
Erythrocytes derive their colour from a
complex protein called hemoglobin. This
substance is composed of a pigment, heme,
containing iron, and the protein glohin.
Hemoglobin has the power to attract oxygen
molecules and to hold them in a loose
chemical combination known as
oxyhemoglobin. It is said, therefore, to have a
chemical affinity for oxygen.
HEMOGLOBIN
Respiratory pigments
 Myoglobin
Hem is also part of the structure of myoglobin,
an oxygen-binding pigment found in red
(slow) muscles and in the respiratory enzyme
cytochrome c. Porphyrins other than that
found in hem play a role in the pathogenesis of
a number of metabolic diseases (congenital
and acquired porphyria, etc.) It may be the
reserve pigments, which give the tissue
oxygen in a small oxygen condition.
MYOGLOBIN
Methods for determination of
hemoglobin
To determine hemoglobin levels proposed many
different methods:
 Gas metric method - measuring the amount of
bound oxygen (1 g Hb can connect 1.36 ml of
oxygen);
 Iron metric - measuring iron levels in the blood
(iron content in Hb is 0.34%);
 Colorimetric - comparing the color of the
solution to the color of the blood of the
standard solution.
Types of hemolysis of
erythrocytes
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Osmotic
Mechanical
Thermal
Biological
Chemical
Osmotic resistance of
erythrocytes
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The minimum osmotic
resistance of erythrocytes
observed in fresh blood
0,50-0,45% NaCl,
maximum - to 0,340,32% NaCl.
The viscosity of the blood
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It is the friction that
occurs between layers of
fluid moving at different
speeds. As in the
bloodstream at different
rates move blood cells
and plasma, the viscosity
just depends on them.
Determine the figure
using viscometer.
Normally, blood viscosity
is about 5 (as the
viscosity of water is 1).
Hematocrit
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Volume ratio of blood
cells called plasma and
hematocrit.
Normally it is men 0,400,48 l / l (40-48%) in
women - 0,36-0,42 l / l
(36-42%).
Erythrocyte sedimentation rate
(ESR)
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Density or specific gravity of erythrocytes
(1,098) is higher than plasma (1.027) and
therefore in vitro with blood clot devoid of
ability, they slowly settle to the bottom.
Erythrocyte sedimentation rate in healthy male
is 2-10 mm per hour, and a woman - 2-15 mm
per hour. In newborns, it is only 1.2 mm per
hour. Intensive physical work leads to
decreased ESR. Pregnant sedimentation rate
can reach 45 mm per hour.