8_1_1-BloodLecture

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Transcript 8_1_1-BloodLecture

Blood
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Blood
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Connective tissue
Transports substances to maintain
homeostasis=main function
Average adult has 5 liters of blood
Blood is 4 times more viscous as water
Hematocrit measures # cells/volume
45% is made of rbc, wbc, platelets
55% plasma (water, amino acids, proteins,
carbohydrates, lipids, vitamins, hormones,
electrolytes, cellular waste)
What are the general
characteristics of Red blood cells?
Erythrocytes
– Biconcave disk, 7.5 micrometers
– Transport gas
– No nucleus when mature
– 1/3 hemoglobin (has iron and makes blood
red)
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Oxyhemoglobin
Deoxyhemolgobin
Immature RBCs have nuclei
Cannot divide-no protein synthesis or division
Extremely flexible
Sickle cell is caused by an abnormal form of hemoglobin
RBC Counts
4,600,000/cubic centimeter is normal
 Number of circulating red cells determines
oxygen carrying capacity
 Each RBC is capable of transporting up to
four oxygen (O2) molecules
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Destruction of RBCs
Average RBC lives 120 days
 As they age, they become fragile
 Macrophages destroy old/damaged rbcs in
liver and spleen
 Recycled to hematopoietic tissue in red
bone marrow
 Hemeironbiliverdinbilirubinbile
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Construction of RBCs=
Hematopoiesis/Erythropoeisis
Prenatal-yolk sac, liver, spleen
 Postnatal-red bone marrow
 Erythropoietin controls rate of RBC
synthesis
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– Kidneys and liver respond to oxygen debt
Dietary Factors
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B-Complex Vitamins (B12 and Folic acid)
– Needed for DNA synthesis
– Hematopoietic tissue is especially vulnerable
to deficiency
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Iron
– Absorbed slowly from food
– reused
Anemia- RBC disorder
reduction of oxygen-carrying capacity
of blood
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Too few RBCs Made
– Iron defeciency
– B complex deficiency
– Erythropoietin
deficiency
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Too many RBCs
destroyed
– Sickle cell anemia
– Sickle trait
– Thallasemias Alpha hemoglobin chain
 Beta hemoglobin chain
 Small rbcs
Artist’s rendering of the 3D structure of the proteien hemoglobin
Normal blood cells
White Blood Cells- leukocytes
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Neutrophils-lobed nucleus
– 54% to 62% leukocytes
– Stain purple, granulocyte
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Eosinophils
– Stain red, 1-3%-granulocyte
Basophils-, 1%-granulocyte
 Monocytes- largest, 3-9%- agranulocyte
 Lymphocytes- small, round, 25-33%, long-livedagranulocyte. These function to attack antigens
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White Blood Cell Counts
5,000-10,000 is normal
 A rise indicates infection-leukocytosis
 A rise also occurs with some leukemias
 A decrease (leukopenia) may indicate viral
infections
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Differential White Blood Cell Count
Normal values for total WBC and differential in adult males and
females are:
Total WBC: 4,500 - 10,000
Bands or stabs: 3 - 5 %
Granulocytes (or polymorphonuclears)
Neutrophils (or segs): 54 - 67% relative value (2500-7000
absolute value)
Eosinophils: 1 - 3% relative value (100-300 absolute value)
Basophils: 0.4% - 1% relative value (40-100 absolute value)
Agranulocytes (or mononuclears)
Lymphocytes: 25 - 35% relative value (1700-3500 absolute
value)
Moncytes: 4 - 6% relative value (200-600 absolute value
Normal ‘DIFF’
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Normal values for total WBC and differential in
adult males and females are:
Total WBC: 4,500 - 10,000
Bands or stabs: 3 - 5 %
Granulocytes (or polymorphonuclears)
– Neutrophils (or segs): 50 - 70% relative value (2500-7000
absolute value)
– Eosinophils: 1 - 3% relative value (100-300 absolute value)
– Basophils: 0.4% - 1% relative value (40-100 absolute
value)
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Agranulocytes (or mononuclears)
– Lymphocytes: 25 - 35% relative value (1700-3500 absolute
value)
– Moncytes: 4 - 6% relative value (200-600 absolute value
What Diffs may Indicate:
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Increased neutrophils indicates a bacterial infection
Increased eosinophils-allergic reaction, parasitic
infections
Low lymphocytes-HIV
Low basophil count with low neutrophil count may
indicate future leukemia, basophils increase during
infections and release histomines
Elevated monocytes: - chronic inflammation
- stress response
- hyperadrenocorticism
- immune mediated disease
- pyogranulomatous disease
- necrosis
- red cell regeneration
Functions of WBCs
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Protect against infection
Phagocytize bacterial cells
Produce antibodies
Diapedesis - allows WBCs to leave circulation
Phagocytes contain lysosomes to break down
Release heparin and histamine (basophils)
– Heparin prevents clots
– Histamine increases blood flow
Lymphoyctes – Immunity by antibody production
 Pus is made of leukocytes, bacteria, and
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Platelets (thrombocytes)
Fragmented megakaryocytes
 No nucleus
 Live 10 days
 130,000-360,000 is normal
 Patients with leukemia bleed due to a
platelet deficiency
 Initiate blood clots
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Scanning electron microscope image of a group of platelets forming a clot
Plasma
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Plasma proteins
– Albumins
 Small, 60%, regulate water movement, depleted
by dehydration
– Globulins
 36% of plasma proteins
– Alpha, bets, and gamma
– Transport lipids and fat-soluble vitamins
– antibodies
– Fibrinogen
 4%, blood coagulation
 Converted to fibrin during blood coagulation
Nutrients in Plasma
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Plasma nutrients
– Amino acids
– Sugars
– Nucleotides
– Lipids
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Lipoprotein molecules
– VLDL-triglycerides
– LDL-cholesterol
– HDL-high protein
Dissolved Gases in Plasma
Oxygen
 Carbon dioxide
 Nitrogen
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Electrolytes in Plasma
Sodium
 Potassium
 Calcium
 Magnesium
 Chloride
 Bicarbonate
 Phosphate
 Sulfate
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Hemostasis
Vasospasm, a few minutes - smooth
muscles contract
 Platelet plug, serotonin released,
vasoconstriction
 Blood Coagulation-forms a clot, many
clotting factors and is most effective
hemostatic mechanism
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– Prothrombin to thromgin to fibrinogen to
fibrin to clot
– Positive feedback
RBCs stuck in a web of fibrin
What keeps blood from clotting?
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Coagulation is usually limited to blood that
is standing still
More on ClottingHematoma - many clots due to blood
leakage aka “bruise”
 Thrombus - abnormal blood clot in a
vessel
 Embolus - a dislodged thrombus, blocks
blood flow
 Atherosclerosis - accumulations of fatty
deposits along the wall of an artery
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Blood Groups and Transfusions
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1665 - The first Blood transfusions of record take place. Animal
experiments conducted by Richard Lower, an Oxford physician
started as dog-to-dog experiments and proceeded to animal-tohuman over the next two years. Dogs were kept alive by the
transfusion of blood from other dogs.
1667 - Jean-Baptiste Denis in France reported successful
transfusions from sheep to humans.
1678 - Transfusion from animals to humans, having been tried in
many different ways, was deemed to be unsuccessful, and was
subsequently outlawed by the Paris Society of Physicians because of
adverse reactions, many resulting in death.
1795 - In Philadelphia an American physician, Philip Syng Physick,
performed the first known human Blood transfusion, although he
did not publish the particulars. Landsteiner- father of blood banking
More History…
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1818 - James Blundell, a British obstetrician, performed the first successful
transfusion of human Blood to a patient for the treatment of postpartum
hemorrhage. Using the patient's husband as a donor, he extracted a small
amount of Blood from the husband's arm and, using a syringe, he
successfully transfused the wife. Between 1825 and 1830, he performed ten
documented transfusions, five of which proved beneficial to his patients,
and published these results. He also devised various instruments for
performing Blood transfusions.
1840 - In London England, Samuel Armstrong Lane, aided by consultant
Dr. Blundell, performed the first successful whole Blood transfusion to treat
hemophilia.
1867 - English surgeon Joseph Lister utilized antiseptics to control infection
during Blood transfusions.
1873 to 1880 - Physicians in the United States are documented, during
these years, to have transfused milk (from cows and goats) to humans.
1884 - Saline infusion replaced milk as a 'Blood substitute' due to increased
frequency of adverse reaction to milk.
1901 - Karl Landsteiner, an Austrian physician, and the most important
individual in the field of Blood transfusion, documented the first three
human Blood groups (based on substances present on the red Blood cells),
A, B and O.
1902 - A fourth main Blood type, AB was found by A. Decastrello and A.
Antigens and Antibodies
Antigens on RBC
 Antibodies in the plasma
 ABO group and Rh group can cause
serious transfusion reactions
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– Mismatched blood
 Clotting, hemolysis, jaundice, kidney failure
ABO
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Erythrocytes contain 1 of 4 antigen
combinations
–A
–B
– AB
– None
Antibodies
Synthesized at 2 to 8 months
 If you are type A, you synthesize anti–b,
can get A and O blood
 If you are type B, you synthesize anti-a,
can get B and O blood
 If you are type O, you synthesize both
anti-a and anti-b, universal donor, only O
 If you are type AB, you synthesize no
antibodies, universal recipient, any type of
blood OK
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Rh Factor
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Rh (rhesus monkey)
Antigen D present: Rh Positive (there are other antigens
that can create problems as well)
Antigen D absent: Rh negative
Rh negative individuals cannot be transfued with positive
blood once exposed to it
Rh negative mother can develop antibodies to RH
positive baby
– BLUE BABIES, ERYTHROBLASTOSIS FETALIS, DESTROY FETAL
CELLS, RhoGAM shots are now given –must be within 72 hours
of Rh Positive contact (miscarry, amniocentesis, abortion, birth)