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Lesson # 3. (Chapter 19). Blood-1. Objectives:. 1- To describe the general characteristics of blood and its major functions. 2- To describe the types of blood cells. 3- To describe the functions of red blood cells. - PowerPoint PPT Presentation
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Blood-1Lesson # 3 (Chapter 19)
Objectives:1- To describe the general characteristics of blood and its major functions.2- To describe the types of blood cells.3- To describe the functions of red blood cells.4- To list the blood types and explain the importance and basis of blood typing. 5- To discuss the reaction sequences responsible of blood clotting.
The Cardiovascular
System
Blood
Blood vessels
It transports substances from place to place in the body.
It is the liquid medium in which these substance travel.
The plumbing that ensure the proper routing of blood to its destination.
The muscular pump that makes blood to circulate through the blood vessels.
Heart
Introduction to the Cardiovascular System
BloodBlood is specialized fluid of connective tissue, which contains cells suspended in a fluid matrix.
1- Transport of dissolved substances
2- Regulation of pH and ions
3- Restriction of fluid losses at injury sites
4- Defense against toxins and pathogens
6- Stabilization of body temperature
Functions of Blood
Oxygen and carbon dioxide, nutrients, hormones, immune system components , waste products.
Blood eliminates deficiencies or excesses of ions. It also absorbs and neutralizes acids generated by active tissues.
Blood contains enzymes and other substances that initiate the process of clotting.
Blood transports white blood cells that migrate into other tissues to fight infections and to remove debris. Blood also contains and delivers the antibodies.
Blood absorbs the heat generated by active skeletal muscles and distributes it to other tissues. If body temperature increases, the heat is lost through the skin blood vessels. If body temperature is too low, the warm blood is directed to the brain and other temperature-sensitive organs.
Composition of Whole Blood
Plasma (46-63%)
Formed elements (37-54%)
Plasma is 92% water in which are dissolved proteins and a mixture of other materials (hormones, nutrients, wastes and electrolytes).
Albumins (60%)
Fibrinogen (4%)
Globulins (35%)
They are made in the liver.
Functions: Major contributors to osmotic pressure of plasma. Transport lipids and steroids hormones.
It is also made in the liver.Functions: Essential component of clotting system.
They are produce by white blood cells (lymphocytes) and by the liver.
Functions: Antibodies. Transport ions, hormones and lipids.
Regulatory proteins (< 1%)Enzymes, proenzymes and hormones.
The Composition of Plasma
PLASMA PROTEINS
(7%)
Electrolytes
Organic waste
Organic Nutrients
A normal ion composition is essential for vital cellular activities. Ions contribute to osmotic pressure of body fluids.
They are carried to sites of breakdown or excretion.Ex: Urea, uric acid, creatinine, bilirubin, ammonium ions.
Lipids (fatty acids, cholesterol, glycerides), carbohy-drates (glucose), and aminoacids.
OTHER SOLUTES
(1%)
Functions:
They are ions produce by the dissociation of salts in water: Na+, K+, Ca2+, Mg2+, Cl-, HCO3
-, HPO4-, SO4
2-
They are used for ATP production, growth and cell maintenance.
Functions:
Tissue
Arteriole Venule
Capillary
Lung
CO2
Wastes
O2
Nutrients
Venule Arteriole
O2 rich,CO2 poor blood
O2 poor,CO2 rich blood
Gas Exchange
Capillary
CO2 O2
Venae cavae
Aorta
Pulmonary arteries
Pulmonary veins
The Cardiovascular System
PulmonaryCircuit
SystemicCircuit
Tissue
CO2
Wastes
O2
Nutrients
1- Blood Hydrostatic Pressure (BHP) pushes water outside the blood vessels
BOP > BHP
2- Blood Osmotic Pressure (BOP) pulls water back to the blood vessels
BHP > BOP
Blood Osmotic Pressure of the blood depends on:
3- Erythrocytes
1- Electrolytes ( mainly sodium ions)
2- Proteins (mainly albumin)
Venule Arteriole
BHP
BOP
If the osmolarity of the blood is too high, the blood stream absorbs too much water, the blood volume raises, and blood pressure increases.
Ex: Patients with high blood pressure must reduce the intake of salt in the diet.
If the osmolarity of blood drops too low, too much water remains in the tissues and they become swollen (edematous).
KwashiorkorChildren with severe protein deficiency.
Neutrophil
Erythrocyte
Eosinophil
Monocyte
Neutrophil
Basophil
Neutrophil
Platelets
Monocyte
Smalllymphocyte
Smalllymphocyte
Largelymphocyte
Formed Elements of Blood
Red Blood Cells or Erythrocytes
Red blood cells constitute 99.9% of all the formed cell in blood.
Number of RBCs in 1 microliter of whole blood: Male: 4.5–6.3 millionFemale: 4.2–5.5 million
Packed cell volume (PCV) or Hematocrit). It is the percentage of RBCs in centrifuged whole blood:Male: 40–54%Female: 37–47%
Erythrocytes lack of nucleus and other organelles and live only an average of 120 days.
They contain the hemoglobin, which transport O2 and CO2.
They are biconcave discs, thick in the outer edges and thin in the center.
Hemoglobin is a protein that gives the RBCs their color and name. Each RBC contains about 280 million molecules of hemoglobin (33% of the cytoplasm).
Normal hemoglobin (adult male): 14–18 g/dL whole bloodNormal hemoglobin (adult female): 12–16 g/dL, whole blood
Hemoglobin
Hemoglobin has a complex quaternary structure consisting of four globular protein subunits.
Each chain contains one molecule or group heme.
Each heme contains one iron ion, which associates easily with oxygen (oxyhemoglobin) OR dissociate easily from oxygen (deoxyhemoglobin).
Fe2+
Hb + O2Deoxyhemoglobin
HbO2Oxyhemoglobin
Each RBC contains about 280 million molecules of hemoglobin.Each RBC potentially can carry more than a billion molecules of O2 (280 x 4)
4
Hemoglobin Conservation and Recycling
BONE MARROW
LIVER
KIDNEYS
LARGE INTESTINESMALL INTESTINE
Macrophage in spleen, liver, bone marrow
BLOOD PLASMA
Hb
10% Hemolysis
Amino- acids
Heme
Biliverdin
Bilirubin
Bilirubin-derived products
Urobilins, Stercobilins
Bilirubin
Eliminated in feces
Eliminated in urine Bilirubin
Excreted in bile Absorbed into
the circulation
Bilirubin-derived products
120 days average life span (90%)
RBC formation
Fe2+ Fe2+ is transported in circulation by transferrin
If is called hemoglobinuria
Bilirubin
+ Albumin
Indirect or unconjugated bilirubin. It increases in accelerated erythrocyte hemolysis (erythroblastosis fetalis, hemolytic anemia), and hepatocellular disease
Direct or conjugated bilirubin.It increases in obstruction of the biliary ducts (cancer of pancreas’ head), gallstones or hepatocellular diseases such as cirrhosis or hepatitis.
Transferrin
When iron is released into the blood stream, it binds to transferrin, a plasma protein
Excess transferrins, are removed in the liver and spleen and the iron is stored in two special proteins-iron complex: ferritin and hemosiderin.
Iron
Ferritin
Hemosiderin
Plasma protein that transports iron
Protein-iron complex that stores iron
Protein-iron complex that stores iron
Iron Metabolism
Erythrocyte production is called erythropoiesis, which normally takes 3 to 5 days.
Myeloid stem cell
Erythrocytes have no repair mechanisms because they lack of nucleus and other organelles. They live only an average of 120 days.
RBC Production
About 1% of circulating RBCs are replaced everyday.
In this process, about 3 million new RBCs enter the blood stream each second.
White blood cells (leucopoiesis)
Erythropoiesis takes place in the red bone marrow.
Synthesis of hemoglobin (80%).
Nucleus
Pro- erythroblast
Day 1
Erythroblast
Day 3
Normoblast
Day 4
Reticulocyte
Day 5-7
Mature Red Blood Cell
Circulation
Erythropoiesis requires: - Aminoacids- Iron- Vitamins B12, B6, and folic acid
Erythropoiesis is stimulated by: - Erythropoietin- Thyroxine - Androgens- Growth hormone
Blood TypesBlood types and transfusion compatibility are a matter of interaction between antigens and antibodies.
Antigens
They are foreign substances that are able to trigger an immune response. Most of antigens are proteins.
Antibodies
They are proteins produced by cells of the immune system, which are able to recognize an interact with the corresponding antigens.
Plasma cellAntigens
Y
Y YY Y
Y
Y Y
Y YY
Antigen-antibody reaction is specific, meaning that the antibodies can recognize only the corresponding antigens.
Plasma cellAntigens
Y
Y YY Y Y
Y Y
YY Y
Plasma cell
Antigens
Plasma cell
C
CC C
C
Antigens
CC
C C
C
The plasma membrane of the cells contains glycoproteins (surface markers) on the outer surface that can act as antigens. That means that they can trigger an immune response and can interact with the corresponding antibodies.
Surface markers are genetically determined and are different in every person. They are responsible for transplant rejection.
CC
C
C
CTransplant rejection is a process in which a transplant recipient's immune system attacks the transplanted organ or tissue.
Blood types and transfusion compatibility are a matter of interaction between plasma antibodies and surface antigens in the erythrocytes.
The plasma membrane of the erythrocytes contains glycoproteins on the outer surface that can act as antigens. That means that they can interact with the corresponding antibodies.
ABO Blood Group
Type A Type B Type A B Type O
Genotype
A A
B B
A B
A i
Blood Type (Phenotype) Genotype Blood Type (Phenotype)
B i
i i
Blood Types are Genetically Determined
A
B
A B
A
B
O
Plasma contains antibodies against surface antigens that are not present on self cells. That is why foreign tissues are rejected by the immune system.
Plasma contains antibodies against surface antigens that are not present on self red blood cells.
Anti-B antibodies Anti-A antibodies Neither anti-A nor anti-B antibodies
Anti-A and anti-B antibodies
When antibodies attack, the foreign cells agglutinate (clump together). This process is called agglutination.
The antigens that determine the blood types are called agglutinogens, and the corresponding antibodies are called agglutinins
+ Ab
ControlBlood Type
A
B
AB
O
ABO Blood Typing
DD
D
D
DD
D
D
Rh + Rh -
No anti-D antibodies
No anti-D antibodies
Genotypes DD or Dd Genotype dd
The Rh blood group is named for the rhesus monkey, the animal in which the Rh antigens were discovered in 1940.
This group include numerous antigens (C, D, E). Antigen D is by far the most reactive and it is used for Rh typing.
Rh Blood Group
Anti-A Anti-B Anti-DControl Anti-A Anti-B Anti-DControl
A-
A+
B-
B+
AB-
AB+
O-
O+
ABO and Rh Blood Typing
Type B(anti-A)recipient
Blood fromtype A donor
Donor RBCsagglutinated byrecipient plasma
Agglutinated RBCsblock small vessels
Transfusion Reaction
Free hemoglobin can block the kidney tubules and produce death from acute renal failure within a week or so.
The agglutinated RBCs lodge in smaller blood vessels and cut of the blood flow to vital organs.
Hemolytic Disease of Newborn
Rh antibodies attack fetal blood causing severe anemia and toxic brain syndrome (Hemolytic Disease of the New Born).
leaves
Uterus
Placenta
Rh- mother
(a) First pregnancy (b) Between pregnancies (c) Second pregnancy
Rhantigen
Rh+ fetus
Amniotic sacand chorion
Anti-Dantibody
SecondRh+ fetus