bloodandclottingSTUDENT.ppt
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Transcript of bloodandclottingSTUDENT.ppt
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Blood
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Blood The only fluid tissue in the human body Classified as a connective tissue Components of blood
1) Living cells called ________________ Erythrocytes red blood cells
transports oxygen and carbon dioxide Leukocytes white blood cells
defend body against pathogens Platelets cell fragments formed
from megakaryocytes, important in blood clotting
2) Non-living matrix: plasma is the fluid and solutes
Bukar Alibeformed elements
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Blood Hematocrit and Beyond When blood is centrifuged
Erythrocytes sink to the bottom (45% of blood, a percentage known as the hematocrit)
Buffy coat contains leukocytes and platelets (less than 1% of blood), the buffy coat is a thin, whitish layer between the erythrocytes and plasma
__________rises to the top (55% of blood)
Average blood volume Women = 5.0 L Men = 5.5 L
Bukar AlibePlasma
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kwashiorkor
280-300 milliosmoles per liter (we will use 300 mOsm/L)
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Physical Characteristics of Blood Blood is used as a vehicle of transport Color range
Oxygen-rich blood is scarlet red Oxygen-poor blood is dull red
pH between 7.357.45 (________) Blood temperature is slightly higher than body temperature at 38
(100.4F), it transfers heat throughout the body
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Blood Plasma is ~90% Water 6-8% proteins which: increase osmotic pressure, buffer H+, increase
blood viscosity, provide fuel during starvation 3 Major Classes of Plasma Proteins (synthesized in liver, except some
globulins synthesized by lymphocytes) Albumins: Major contributor to plasma oncotic osmotic pressure
and act as carriers Globulins: Carriers, Clotting factors, Precursor proteins
(angiotensinogen), Immunoglobulins Fibrinogen: Blood Clotting
Nutrients: glucose, amino acids, lipids, vitamins Wastes: urea, bilirubin, creatinine Gases (dissolved): oxygen, carbon dioxide Hormones Electrolytes (aka _____________)
Relatively high concentrations of Na+ and Cl- Relatively low concentrations of H+, HCO3-, K+, and Ca2+
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Ringers Solution A solution of distilled water containing electrolytes and compounds
so that the same concentrations as their occurrence in body fluids. This solution is iso-osmotic to our blood and tissues Why? 280-300 milliosmoles per liter (we will use __________ mOsm/L) Blood and tissue osmolarity must be equal to prevent net movement of fluids
tissue tissue blood blood
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Osmosis Water (solvent) diffuses down its concentration gradient
The Link Between Water and Salt Solutes in the body include
electrolytes like sodium, potassium, and calcium ions
Changes in electrolyte balance causes water to move from one compartment to another which alters blood volume and blood pressure and can impair the activity of cells
Water moves from low [solute] to high [solute]=high [solvent] to low [solvent]
Pure water has ______ solute present Water reabsorption follows solute
reabsorption
More solvent
Less solvent
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Blood Plasma
Acidosis: blood becomes too acidic (less than 7.35) Alkalosis: blood becomes too basic (greater than 7.45) In each scenario, the respiratory system and kidneys help
restore blood _________ to normal Carbon dioxide can dissolve in water (blood plasma) and
form carbonic acid
CO2 + H2O H2CO3 (carbonic acid) H+ + HCO3- (bicarbonate)
Im an acid!
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Acid-Base Balance Normal pH of arterial blood = 7.4
pH < 7.35 = ___________ pH > 7.45 = alkalosis
Most ions originate as by-products of cellular metabolism Complications with acid-base
disturbance Conformation change in protein
structure Changes in excitability of
neurons Changes in balance of other ions Cardiac arrhythmias Vasodilation/vasoconstriction
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Acids and Bases
Acids are proton (H+) donors Strong acids dissociate completely and liberate all
of their H+ in water Weak acids, such as carbonic acid, dissociate only
partially Bases are proton (H+) acceptors
Strong bases dissociate easily in water and tie up H+ Weak bases, such as bicarbonate ion and ammonia,
are slower to accept H+
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Cellular or Formed Elements
Erythrocytes: Red blood cells (RBCs)
Leukocytes: _________ blood cells (WBCs)
Platelets (cell fragments)
Multipotent stem cell
Bukar Alibewhite
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Developmental Aspects of Blood Cells
Sites of blood cell formation The fetal liver and spleen are early sites of
blood cell formation Bone marrow takes over hematopoiesis by
the seventh month Fetal hemoglobin differs from hemoglobin
produced after birth, fetal hemoglobin has a gamma subunit in place of the beta subunit and ______________ affinity for oxygen
Physiologic jaundice results when the liver cannot rid the body of hemoglobin
breakdown products fast enough
Bukar AlibeHIGHER
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Erythrocytes
Erythrocytes (red blood cells or RBCs) Main function is to carry oxygen Anatomy of circulating erythrocytes
biconcave disk: large surface area which favors diffusion
Essentially bags of hemoglobin Anucleate (no nucleus) Contain very few organelles No _________________ Use anaerobic glycolysis
5-6 billion RBCs per ml of blood Flexible membrane Also function to maintain osmolarity and
blood/plasma pH
Bukar Alibemitochondria
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Hemoglobin in RBCs Hb binds strongly (but reversibly) to oxygen 98.5% oxygen bound to Hb and 1.5% dissolved
in plasma Each hemoglobin molecule has four oxygen
binding sites Globin + 4 heme groups = 4 polypeptides and
_______________ = iron-containing group Iron-containing protein Can also bind to CO2 and H+
Bukar AlibeHEME
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Formation of Erythrocytes
Mature RBCs are unable to divide, grow, or synthesize proteins Wear out in 100 to 120 days When worn out, RBCs are eliminated by phagocytes in the spleen or
liver Lost cells are replaced by division of hemocytoblasts in the red bone
marrow __________________ is a component of hemoglobin Normal hemoglobin content of blood
Men: 13 18 gram /dL Women: 12 16 gram /dL
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Control of Erythrocyte Production Rate is controlled by a hormone (________________) Kidneys produce most erythropoietin as a response to reduced oxygen levels in the blood (sensed by chemoreceptors) Homeostasis is maintained by negative feedback from blood oxygen levels
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Control of Erythrocyte Production
Reduced O2 levels in blood-sensed by chemoreceptors
Stimulus: Decreased RBC count, decreased availability of O2 to blood, or increased tissue demands for O2 Increased
O2- carrying ability of blood
Kidney releases erythropoietin Enhanced
erythropoiesis Red bone marrow
More RBCs
Normal blood oxygen levels 100 mmHg
Erythropoietin stimulates
60 mmHg
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Anemia: Decrease in the oxygen-carrying capacity of blood
Dietary anemia Iron: iron-deficiency anemia Pernicious: lack of Vitamin B12
Hemorrhagic anemia: bleeding Hemolytic anemia
Malaria or Sickle cell anemia Aplastic anemia: bone marrow
defect ________ anemia: kidney disease
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Anemia
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Leukocytes (white blood cells) Leukocytes (white blood cells or
WBCs) Crucial in the bodys defense
against disease These are complete cells, with a
nucleus and organelles Able to move into and out of blood
vessels (diapedesis) Can move by ____________
motion though tissues Can respond to chemicals released
by damaged tissues (cytokines) 4,000 to 11,000 WBC per cubic
millimeter (microliter) of blood
Bukar Alibeamebolic
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Types of Leukocytes Two Major Classes of Leukocytes Granulocytes Granules in their cytoplasm can be stained Possess lobed nuclei Include 1)neutrophils, 2)eosinophils, and 3)basophils
Agranulocytes Lack visible cytoplasmic granules Nuclei are spherical, oval, or kidney-shaped Include:
1)lymphocytes 2)_________________
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Abundance of Leukocytes List of the WBCs from most to
least abundant Neutrophils Lymphocytes Monocytes Eosinophils Basophils
Easy way to remember this list Never Let Monkeys Eat Bananas
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Granulocyte: Neutrophils Neutrophils are multilobed nucleus with fine granules 40-70% of leukocytes in blood Phagocytes at active sites of infection Secretes ____________________ Circulate in blood 7-10 hours Migrate to tissues for a few days Increase in number during infections
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Granulocyte: Eosinophils 1-4% of leukocytes Large brick-red cytoplasmic granules Phagocytes (but ___________ main mechanism of action) Defend against parasitic invaders (e.g. worms) Granules contain toxic molecules that attack parasites
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Granulocyte: Basophils
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Agranulocytes: Monocytes become Macrophages
4-8% of leukocytes __________________ New monocytes circulate in blood for
a few hours then Migrate to tissues macrophages Wandering macrophages Fixed macrophages
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Agranulocytes: Lymphocytes 20-45% of WBCs 3 types of Lymphocytes ____ lymphocytes (B cells) T lymphocytes (T cells) Null cells (also called
natural killer or NK cells)
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Lymphocytes: B Cells B cells associated with antibodies 2 major classes of B cells:
1)effector B cells become plasma cells and secrete antibodies
2) __________________ B cell contacts antigen then
become a plasma cell Plasma cell secretes antibodies
(immunoglobulins) Antibodies mark invaders (called
antigens) for destruction Anti=antibody and
Gen=generator
Bukar AlibeMEMORY CELLS
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Lymphocytes: T Cells Helper T Cells secrete cytokines that enhance activity of B cells and
other T cells enhances activity of macrophages and NK cells Cytotoxic T Cells kill virus-infected cells, abnormal cells, and bacteria,
Secretory products form pores in target cell membrane, Kills cells by lysis
Memory T cells used for ______________________ infection Suppressor (regulatory) T Cells secrete cytokines that suppress activity
of B cells and other T cells and used to end an immune response
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Lymphocytes: Natural Killer Cells (Null Cells)
Recognize abnormal or infected cells cause lysis by secreting ____________
Can attack virus-infected cells without identifying virus Early defense against viral infections Cause lysis
Fast acting early immune response
MHC=major histocompatibility complex
(a) Inhibitory NK cell receptors recognize self MHC class I and restrain NK cell activation.
(b) When unimpeded by the inhibitory receptors, binding of NK cell activation receptors to their ligands on target cells results in NK cell stimulation.
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Leukocyte Issues Abnormal numbers of leukocytes
Leukocytosis WBC count above 11,000 leukocytes/mm3 Generally indicates an infection
____________ Abnormally low leukocyte level Commonly caused by certain drugs such as corticosteroids
and anticancer agents Leukemia occurs when bone marrow becomes cancerous, turns out excess WBC
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Platelets Platelets (a.k.a. thrombocytes)
Derived from ruptured multinucleate cells ( ___________________)
Needed for the clotting process Normal platelet count = 300,000/mm3(l)
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Characteristics of Formed Elements of the Blood
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Characteristics of Formed Elements of the Blood
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Hematopoiesis Blood cell formation Occurs in red bone marrow All blood cells are derived from
a common stem cell (hemocytoblast)
Hemocytoblast differentiation Lymphoid stem (lymphoblast)
cell produces lymphocytes Myeloid stem (____________)
cell produces all other formed elements
Erythrocyte synthesis stimulated by erythropoietin secreted from kidneys under conditions of low oxygen levels in blood flowing to kidneys
monocyte
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Formation of White Blood Cells and Platelets
Controlled by hormones Colony stimulating factors (CSFs) and _____________
prompt bone marrow to generate leukocytes Thrombopoietin stimulates production of platelets
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Hemostasis Stoppage of bleeding resulting from a break in a blood vessel Hemostasis involves three phases 1) Vascular _________________ Vasoconstriction causes blood vessel to
spasm Spasms narrow the blood vessel,
decreasing blood loss 2) Platelet plug formation Collagen fibers are exposed by a break
in a blood vessel a platelets become sticky and cling to fibers
Anchored platelets release chemicals to attract more platelets
Platelets pile up to form a platelet plug 3) Coagulation (blood clotting)
Bukar AlibeSPASMS
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Platelet Components
Platelet Plug needed for formation of a blood clot Colorless Cell fragments
no _______________ has organelles & granules
100,000 500,000 / mL blood
Dam
aged
tiss
ue
Hea
lthy
tissu
e
Bukar AlibeNUCLEUS
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Preventing the Spread of Plug Chemicals that prevent platelet aggregation: Prostacyclin (PGI2) - produced in healthy endothelial cells Nitric oxide released by healthy endothelial cells ______ is an integral membrane protein that keeps ADP levels low 5 factors that activate a platelet plug are highlighted
Bukar AlibeCD39
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Aspirin Prevents_____________________activation Inhibits the activation of thromboxane A2
Bukar AlibePLATELET
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Hemostasis Coagulation
Injured tissues release tissue factor (TF) PF3 (a phospholipid) interacts with TF, blood protein clotting
factors, and calcium ions to trigger a clotting cascade Prothrombin activator converts prothrombin to thrombin (an
enzyme) Thrombin joins fibrinogen proteins into hair-like molecules of
insoluble fibrin Fibrin forms a meshwork
(the basis for a clot) Blood usually clots within
3 to 6 minutes The clot remains as
endothelium ____________ The clot is broken down
after tissue repair
Bukar AlibeREGENERATES
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Intrinsic and Extrinsic Coagulation Pathways
Intrinsic Pathway trigger = exposed collagen
Extrinsic Pathway Requires Tissue Factor III
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Role of Thrombin in Blood Clotting
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Clot Formation
Fibrinogen
Fibrin (mesh)
(Fibrin clot = blood clot)
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Plasminogen
Plasmin
Dissolves Clot
Dissolving a Clot
Requires another cascade initiated by exposure of collagen
plasminogen activators
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Undesirable Clotting Thrombus
A clot in an unbroken blood vessel Can be deadly in areas like the
heart or brain __________________
A thrombus that breaks away and floats freely in the bloodstream
Can later clog vessels in critical areas such as the brain
Bukar AlibeEMBOLUS
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Role of Coagulation Factors in Clot Formation Disorders
Hemophilia: a group of genetic disorders caused by deficiency of gene for specific coagulation factors
Von Willebrands disease: reduced levels of vWf and decreases platelet plug formation
Vitamin K deficiencies cause decreased synthesis of clotting factors
_______________________ Platelet deficiency Even normal movements can cause
bleeding from small blood vessels that require platelets for clotting
Bukar AlibeTHROMBOCYTOPENIA
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Blood Groups and Transfusions
Large __________________ of blood have serious consequences Loss of 1530% causes weakness Loss of over 30% causes shock, which can be fatal
Transfusions are the only way to replace blood quickly Transfused blood must be of the same or compatible blood group(s)
Bukar AlibeLOSSES
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Human Blood Groups Blood contains genetically
determined proteins _______________(a substance the
body recognizes as foreign) may be attacked by the immune system
Antibodies are the recognizers that attack foreign cells
Blood is typed by using antibodies that will cause blood with certain proteins to clump (agglutination)
There are over 30 common red blood cell antigens
The most vigorous transfusion reactions are caused by ABO and Rh blood group antigens
Bukar AlibeANTIGENS
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ABO Blood Groups
AB+
O-
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ABO Blood Groups Blood type AB can receive A, B, AB, and O
blood, so AB+ is the universal recipient Blood type B can receive B
and O blood Blood type A can receive
A and O blood Blood type O can receive O blood, so O- is the universal donor Blood types: A, B, AB, O Due to antigens on surface of RBCs Type ___ A antigens, anti-B antibodies Type B B antigens, anti-A antibodies Type AB A and B antigens, no A or B
antibodies Type O no modified antigens, anti-A and
anti B antibodies
Bukar AlibeA
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Blood Typing Blood samples are mixed with anti-A
and anti-B serum ______________ or no agglutination
leads to determining blood type Typing for ABO and Rh factors is
done in the same manner Cross matchingtesting for
agglutination of donor RBCs by the recipients serum, and vice versa
Bukar AlibeAGGLUTINATION
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Rh Blood Groups
Named because of the presence or absence of one of eight Rh antigens (agglutinogen D) that was originally defined in Rhesus monkeys Most Americans are Rh+ (Rh positive) Problems can occur in mixing Rh+ blood into a body with
Rh (Rh________________) blood
Bukar AlibeNEGATIVE
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Rh Dangers During Pregnancy: Erythroblastosis fetalis, Rhesus disease
The mismatch of an Rh mother carrying an Rh+ baby can cause problems for the unborn child The first pregnancy usually proceeds without problems The immune system is sensitized after the first pregnancy In a second pregnancy, the mothers immune system produces
antibodies to attack the Rh+ blood (hemolytic disease of the newborn)
Danger occurs only when the mother is Rh and the father is Rh+, and the child inherits the Rh+ factor
A R_____________ shot can prevent formation of anti-Rh+ antibodies in mothers blood-it binds to the
Rh antigen on 1st babys fetal blood, so mom never has an immune response
fetal rhogam
Bukar AlibehoGAM