chapter 8 -blood

8/6/2019 Chapter 8 -Blood

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PowerLecture:PowerLecture:

Chapter 8Chapter 8

BloodBlood


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Learning ObjectivesLearning Objectives

Describe the composition and functions ofDescribe the composition and functions of

blood.blood.

Explain how red blood cells transportExplain how red blood cells transport

oxygen.oxygen.

Explain the basis of blood typing.Explain the basis of blood typing.

DefineDefine hemostasishemostasis and distinguish it fromand distinguish it from

homeostasishomeostasis..

Describe various blood disorders.Describe various blood disorders.


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Section 1

Section 1

Blood: Plasma, BloodBlood: Plasma, Blood

Cells, and PlateletsCells, and Platelets


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Blood: Plasma, Blood Cells, and PlateletsBlood: Plasma, Blood Cells, and Platelets

BloodBloodis ais a connective tissueconnective tissue; it contains; it contains

plasma, blood cells, and cell fragmentsplasma, blood cells, and cell fragments

called platelets.called platelets.

Adult women of average size have 4Adult women of average size have 4--55liters of blood in their bodies; men haveliters of blood in their bodies; men have

slightly moreslightly more..

Blood makes up 6Blood makes up 6--8 % of your body8 % of your bodyweight.weight.


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Fig. 8.1

red

blood

cell

platelets

white

blood

cell


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Plasma is the fluid part of blood.Plasma is the fluid part of blood.

Roughly 55% of whole blood isRoughly 55% of whole blood is plasmaplasma, which, whichis mostly water.is mostly water.

Plasma proteins perform a variety of tasksPlasma proteins perform a variety of tasks:: It transports blood cells and platelets.It transports blood cells and platelets.

AlbuminAlbumin is important in maintaining osmotic balanceis important in maintaining osmotic balanceand transports chemicals such as therapeutic drugsand transports chemicals such as therapeutic drugs..

OtherOther plasma proteins include protein hormones, asplasma proteins include protein hormones, as

well as proteins involved in immunity, blood clotting,well as proteins involved in immunity, blood clotting,and the transport of lipids and vitamins.and the transport of lipids and vitamins.

Plasma further contains ions, glucose, aminoPlasma further contains ions, glucose, aminoacids, signaling molecules, and dissolvedacids, signaling molecules, and dissolved

gases.gases.


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Fig. 8.1

FunctionsComponents Relative Amounts

Plasma portion (50%-60% of total volume):

Plasma portion (50%-60% of total volume):

1.Water

2.Plasma proteins (albumin,globulins, fibrinogen, etc.)

3.Ions, sugars, lipids, amino acids,hormones, vitamins, dissolved

gasses

91%-92% ofplasma volume

7%-8%

1%-2%

Solvent

Defense, clotting, lipid transport,roles in extracellular fluid volume,etc.

Roles in extracellular fluid volume,

pH, etc.

1.White blood cells:NeutrophilsLymphocytesMonocytes(macrophages)EosinophilsBasophils

2.Platelets

3.Red blood cells

3,000-6,7501,000-2,700

150-720100-360

25-90

250,00-300,000

4,800,000-5,400,000per microliter

Phagocytosis during inflammationImmune responsesPhagocytosis in all defense responsesDefense against parasitic wormsSecrete substances for inflammatoryresponse and for fat removal from blood

Roles in clotting

Oxygen, carbon dioxide transport


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Red blood cells carry oxygen and CORed blood cells carry oxygen and CO22..

ErythrocytesErythrocytes, or, orred blood cellsred blood cells, (45% of, (45% of

whole blood) are biconcave disks.whole blood) are biconcave disks.

They contain hemoglobin, an ironThey contain hemoglobin, an iron--containing proteincontaining proteinthat binds with oxygen.that binds with oxygen.

They also carry a small amount of carbon dioxide.They also carry a small amount of carbon dioxide.

Red blood cells originate fromRed blood cells originate from stem cellsstem cells in thein the

bone marrow.bone marrow.


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White blood cells perform defense andWhite blood cells perform defense andcleanup duties.cleanup duties.

LeukocytesLeukocytes, or, orwhite blood cellswhite blood cells, make up a, make up a

minor portion of whole blood and areminor portion of whole blood and areresponsible for housekeeping and defense;responsible for housekeeping and defense;they also are derived from bone marrow.they also are derived from bone marrow.

Leukocytes are of two main types:Leukocytes are of two main types: GranulocytesGranulocytes have stainable granules in thehave stainable granules in the

cytoplasm; they includecytoplasm; they include neutrophilsneutrophils,, eosinophilseosinophils, and, andbasophilsbasophils; and they work in body defense activities.; and they work in body defense activities.

AgranulocytesAgranulocytes have no visible granules;have no visible granules; monocytesmonocytesbecome macrophages; and lymphocytes become Bbecome macrophages; and lymphocytes become B

cells, T cells, and natural killer cells.cells, T cells, and natural killer cells.


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natural

killer cells

eosinophils

neutrophils

basophils

mast cells

B lymphocytes

T

lymphocytes

dendritic cells macrophages

platelets

red blood

cells

(erythrocytes)

forerunnersof

white bloodcells

(leukocytes)

monocytes

(immature

phagocytes)

stem cells

in marrow

megakaryocytes

?

Fig. 8.2


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Platelets help clot blood.Platelets help clot blood.

PlateletsPlatelets are fragments ofare fragments of megakaryocytesmegakaryocytes

produced by bone marrow stem cells.produced by bone marrow stem cells.

They are shortThey are short lived (1 week),lived (1 week), numerous, andnumerous, andfunction in blood clotting.function in blood clotting.


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Section 2

Section 2

How Blood TransportsHow Blood Transports

OxygenOxygen


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How Blood Transports OxygenHow Blood Transports Oxygen

Hemoglobin is the oxygenHemoglobin is the oxygen

carrier.carrier.

Only a tiny amount of oxygenOnly a tiny amount of oxygen

is dissolved in blood plasma.is dissolved in blood plasma.

Most of the oxygen is bound to the heme groupsMost of the oxygen is bound to the heme groups

of hemoglobin; oxygenof hemoglobin; oxygen--bearing hemoglobin isbearing hemoglobin is

calledcalled oxyhemoglobinoxyhemoglobin.. What determines how much oxygenWhat determines how much oxygen

hemoglobin can carry?hemoglobin can carry?


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The amount of oxygen bound to hemoglobinThe amount of oxygen bound to hemoglobin

changes as conditions in the tissues vary.changes as conditions in the tissues vary.

Binding of oxygen is favored by conditions in theBinding of oxygen is favored by conditions in the

lungs: abundant oxygen, cooler temperature, andlungs: abundant oxygen, cooler temperature, and

neutralneutral pH (in lungs).pH (in lungs).

Release of oxygen is favored in the tissues whereRelease of oxygen is favored in the tissues where

the oxygen levels are lower, temperatures higher,the oxygen levels are lower, temperatures higher,

and pH more acidic.and pH more acidic.

Hemoglobin also transports a small amount ofHemoglobin also transports a small amount ofcarbon dioxide.carbon dioxide.


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Hb + O2

more O2cooler

less acidic

less O2warmer

more acidic

TISSUESLUNGS

Hb + O2 HbO2 HbO2


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Each hemoglobin molecule has fourEach hemoglobin molecule has four

polypeptide chains (globin proteins), each ofpolypeptide chains (globin proteins), each of

which possesses a heme group containing anwhich possesses a heme group containing an

iron molecule; each iron binds one molecule ofiron molecule; each iron binds one molecule of

oxygen.oxygen.


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coiled and twisted

polypeptide chain

of one globin

molecule

heme group

Fig. 8.3


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Four polypeptide chains, two types: alpha andFour polypeptide chains, two types: alpha and

beta, each with heme group: iron moleculebeta, each with heme group: iron molecule

binds oxygen. Each hemoglobin moleculebinds oxygen. Each hemoglobin molecule

binds 4 oxygen molecules.binds 4 oxygen molecules.

HemoglobinHemoglobin


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Section 3

Section 3

Making New RedMaking New Red BloodBlood

CellsCells


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Hormonal Control ofHormonal Control of

Red Blood Cell ProductionRed Blood Cell Production

Red blood cells form from stem cellsRed blood cells form from stem cellslocated in red bone marrow.located in red bone marrow.

The hormoneThe hormone erythropoietinerythropoietin from the kidneysfrom the kidneys

is the stimulus for stem cell division.is the stimulus for stem cell division. Mature red blood cells have no nuclei and liveMature red blood cells have no nuclei and live

for only about 120 days.for only about 120 days. Macrophages remove old blood cells from theMacrophages remove old blood cells from the

bloodstream; amino acids are returned to the blood,bloodstream; amino acids are returned to the blood,

iron is returned to the bone marrow, andiron is returned to the bone marrow, and hemehemegroups are converted togroups are converted to bilirubinbilirubin..

RedRed cell countscell counts remain rather constant at 5.4remain rather constant at 5.4million/million/microlitermicroliter for males and 4.8 million forfor males and 4.8 million forfemales.females.


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Hormonal Control ofHormonal Control of

Red Blood Cell ProductionRed Blood Cell Production

A negative feedback loop stabilizes the redA negative feedback loop stabilizes the red

blood cell count.blood cell count.

The kidneys monitor oxygen content of theThe kidneys monitor oxygen content of the

blood; when it drops too low, the kidneysblood; when it drops too low, the kidneyssecrete erythropoietin.secrete erythropoietin.

Erythropoietin stimulates bone marrow toErythropoietin stimulates bone marrow to

produce more red blood cells; this increasesproduce more red blood cells; this increases

the ability of the blood to carry oxygen.the ability of the blood to carry oxygen.

As oxygen levels rise, the information feedsAs oxygen levels rise, the information feeds

back to the kidneys, which stop secretingback to the kidneys, which stop secreting

erythropoietin.erythropoietin.


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Fig. 8.4

Reduced oxygenin blood

The kidneys detectreduced O2 in the blood.

When less O2 is delivered tothe kidneys, they secrete thehormone erythropoietin intothe blood.

Erythropoietin stimulatesproduction of red bloodcells in bone marrow.

The additional circulatingRBCs increase O2 carriedin blood.

The increased O2 relieves theinitial stimulus that triggerederythropoietin secretion.

RBCs

Erythropoietin

Increased oxygenin blood

Kidney

Developingred blood cellsin red bonemarrowRelieves

1

2

3

4

5

1

2

3

4

5


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Why train at high altitude?Why train at high altitude?


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Erythropoietin and production of RBCsErythropoietin and production of RBCs


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Section 4

Section 4

Blood TypesBlood Types

Genetically Different RedGenetically Different RedBlood CellsBlood Cells


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All cells of the human body have surface proteins andAll cells of the human body have surface proteins and

other molecules that serve as self identification markers.other molecules that serve as self identification markers.

Any protein marker that prompts a defensive action isAny protein marker that prompts a defensive action is

called ancalled an antigenantigen..

The human body producesThe human body produces antibodiesantibodies that recognizethat recognizemarkers on foreign cells as markers on foreign cells as nonselfnonself and stimulate and stimulate

immune reactions.immune reactions.


Genetically Different Red Blood CellsGenetically Different Red Blood Cells


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The ABO group of blood types includes keyThe ABO group of blood types includes key

self markers on red blood cells.self markers on red blood cells.

ABO blood groups are based on glycoproteinABO blood groups are based on glycoprotein

surface markers on red blood cells.surface markers on red blood cells. Type A has A markers; type B has B markers.Type A has A markers; type B has B markers.

Type AB has both markers; type O has neitherType AB has both markers; type O has neither

marker.marker.

Depending on ABO blood type, the body willDepending on ABO blood type, the body willalso possess antibodies to other blood types;also possess antibodies to other blood types;

ABO bloodtypingABO bloodtypingis done to preventis done to prevent

incompatible blood types from being mixed.incompatible blood types from being mixed.




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Mixing incompatible blood types can causeMixing incompatible blood types can causethe clumping called agglutination.the clumping called agglutination.

Type A blood types do not have antibodiesType A blood types do not have antibodiesagainst A markers, but they do have antibodiesagainst A markers, but they do have antibodiesto type B; Type B blood types do not have typeto type B; Type B blood types do not have typeB antibodies, but they do have type AB antibodies, but they do have type Aantibodies, etc.antibodies, etc. A type A person cannot donate blood to a type BA type A person cannot donate blood to a type B

person because they areperson because they are incompatibleincompatible.. When mixed, markers on the surface of red bloodWhen mixed, markers on the surface of red blood

cells (not just the ABO markers) that do not matchcells (not just the ABO markers) that do not matchwill cause the blood cells to undergowill cause the blood cells to undergo agglutinationagglutination,,a defense response where the blood cells clump.a defense response where the blood cells clump.




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Table 8.1


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Table 8.2


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Blood TypesBlood Types Genetically Different RedGenetically Different Red

Blood CellsBlood Cells Clumped cells can clog small blood vessels,Clumped cells can clog small blood vessels,

damage tissues, and cause death.damage tissues, and cause death.

Fig.Fig. 8.58.5

incompatible blood cellscompatible blood cells


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Fig. 8.5a

Donortype B blood Recipient with

type A blood

Oxygen and nutrient

flow to cells and tissuesis reduced

Red blood cellsusually burst Clumping blocks blood flow

in capillaries

Side effects disrupt

kidney function

Red blood cells from

donor agglutinatedby antibodies inrecipients blood

Antigen A

Antibody totype B blood

Antibody totype A blood

Antigen B


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Section 5

Section 5

Rh Blood TypingRh Blood Typing


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RhRh blood typing looks for anblood typing looks for an RhRh marker.marker.

RhRh bloodtypingbloodtypinglooks for the presence (looks for the presence (RhRh++))

or absence (or absence (RhRh--) of antigen on red blood cells.) of antigen on red blood cells.

Most people dont have antibodies againstMost people dont have antibodies against RhRhmarker. Anmarker. An RhRh-- person transfused withperson transfused with RhRh++

blood will produce antibodies to theblood will produce antibodies to the RhRh marker.marker.



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Rh Blood TypingRh Blood Typing AnAn RhRh-- mother who bears anmother who bears an RhRh++ child can alsochild can also

become sensitized to thebecome sensitized to the RhRh antigen;antigen;

secondary children may be at risk fromsecondary children may be at risk from

maternal antibodies.maternal antibodies.

InIn hemolytic disease ofthe newbornhemolytic disease ofthe newborn, too many, too many

cells may be destroyed and the fetus dies.cells may be destroyed and the fetus dies.

Medical treatment (Medical treatment (RhoGamRhoGam) given to the mother) given to the mother

after the birth of the firstafter the birth of the first RhRh++ baby can inactivate thebaby can inactivate the

RhRh antibodies.antibodies.


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There are also many other markers on redThere are also many other markers on red

blood cells.blood cells.

Hundreds of different blood cell markers areHundreds of different blood cell markers are

known; most are widely scattered in the humanknown; most are widely scattered in the humanpopulation.population.

To avoid problems with transfusions, bloodTo avoid problems with transfusions, blood

undergoesundergoes crosscross--matchingmatchingto excludeto exclude

incompatible blood types from being used.incompatible blood types from being used.



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Section 6

Section 6

New Frontiers of BloodNew Frontiers of Blood

TypingTyping


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Blood + DNA: Investigating crimes andBlood + DNA: Investigating crimes and

identifying mom or dad.identifying mom or dad.

Blood cell markers can be used to compareBlood cell markers can be used to compare

evidence from crime scenes to samples takenevidence from crime scenes to samples takenfrom possible perpetrators.from possible perpetrators.

Because blood groups are determined byBecause blood groups are determined by

genes, they are a useful source of informationgenes, they are a useful source of information

about a persons genetic heritage.about a persons genetic heritage.

Blood typing can also be used to helpBlood typing can also be used to help

determine the identity of a childs father ordetermine the identity of a childs father or

mother.mother.

New Frontiers of Blood TypingNew Frontiers of Blood Typing


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For safetys sake, some people bank theirFor safetys sake, some people bank their

own blood.own blood.

Even with screening, blood transfusions stillEven with screening, blood transfusions still

carry the risk of being incompatible orcarry the risk of being incompatible orpotentially contaminated with infectious agents.potentially contaminated with infectious agents.

InIn autologous transfusionsautologous transfusions, individuals pre, individuals pre--

donate blood todonate blood to

themselves priorthemselves prior

to surgeries in caseto surgeries in case

transfusion is needed.transfusion is needed.



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Blood substitutes must also avoid sparkingBlood substitutes must also avoid sparkingan immune response.an immune response.

Blood substitutes have potential uses inBlood substitutes have potential uses insituations where it is not feasible to perfectlysituations where it is not feasible to perfectlymatch blood, such as in an ambulance or onmatch blood, such as in an ambulance or onthe battlefield.the battlefield.

To date, however, substitutes haveTo date, however, substitutes have

been difficult to manufacture;been difficult to manufacture;OxygentOxygentTMTM is an oxygen carrieris an oxygen carrier

that has currently reached the finalthat has currently reached the final

stages of clinical trials.stages of clinical trials.



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Section 7Section 7

Hemostasis and BloodHemostasis and Blood

ClottingClotting


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Hemostasis and Blood ClottingHemostasis and Blood Clotting

HemostasisHemostasis prevents blood loss.prevents blood loss.

HemostasisHemostasis is the process that stops bleedingis the process that stops bleeding

to prevent excess loss of blood.to prevent excess loss of blood.

Spasms of the smooth muscle in the damaged bloodSpasms of the smooth muscle in the damaged bloodvessel stop blood flow for a few minutes byvessel stop blood flow for a few minutes by

constriction of the vessel.constriction of the vessel.

Platelets clump to plug the rupture; they then releasePlatelets clump to plug the rupture; they then release

serotonin and other chemicals to prolong the spasmserotonin and other chemicals to prolong the spasm

and attract more platelets.and attract more platelets.

Finally, the bloodFinally, the blood coagulatescoagulates to form the clot.to form the clot.

Chemical signals from cells and platelets convertsChemical signals from cells and platelets converts

soluble fibrinogen into insoluble fibrin, forms a clotsoluble fibrinogen into insoluble fibrin, forms a clot

with trapped red blood cells and platelets.with trapped red blood cells and platelets.


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Fig. 8.8

Ca2+

Blood flow

Fibrinogen

Prothrombin

Thrombin

Fibrin threads

(clot)

Damaged cells andplatelets releasesubstances thatactivate clottingfactors

Injury toblood vessel

Wall of vesselcontracts

Platelets stickto collagen fibersof damaged vesselwall

More permanentclot forms

Blood flowceases

Plateletplug

Blood flowdecreases

Blood flowdecreases

Prothrombinactivator

Ca2+

1 2 3 4


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Factors in blood are one trigger for bloodFactors in blood are one trigger for blood

clotting.clotting.

In theIn the intrinsic clotting mechanismintrinsic clotting mechanism, internal, internal

damage activates a plasma protein (factor X)damage activates a plasma protein (factor X)that triggers the formation ofthat triggers the formation ofthrombinthrombin..

Thrombin acts onThrombin acts on fibrinogenfibrinogen to form insolubleto form insoluble

threads ofthreads offibrinfibrin that will entrap blood cells andthat will entrap blood cells and

platelets to form a clot.platelets to form a clot.

With time, the clot becomes more compact,With time, the clot becomes more compact,

drawing the torn walls of the vessel backdrawing the torn walls of the vessel back

together.together.


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Factors from damaged tissue also canFactors from damaged tissue also can

cause a clot to form.cause a clot to form.

In theIn the extrinsic clotting mechanismextrinsic clotting mechanism, blood, blood

clotting is triggered by the release ofclotting is triggered by the release ofsubstances outside the blood itself due tosubstances outside the blood itself due to

damage there; the pathway is similar to thedamage there; the pathway is similar to the

intrinsic mechanismintrinsic mechanism..

These substances lead to the formation ofThese substances lead to the formation ofthrombin.thrombin.


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Clots that form in unbroken vessels can beClots that form in unbroken vessels can be lifelife--

threatening as it blocks blood flow.threatening as it blocks blood flow.

A clot that stays where it forms is called aA clot that stays where it forms is called a thrombusthrombus

(condition is thrombosis);(condition is thrombosis); one that breaks free andone that breaks free and

moves is called anmoves is called an embolusembolus (condition is embolism).(condition is embolism).

AAstrokestroke occurs when an embolus blocks flow tooccurs when an embolus blocks flow to

some part of the brain.some part of the brain.

HemophiliaHemophilia is a genetic disorder where clottingis a genetic disorder where clotting

factors are absent from the blood so it does notfactors are absent from the blood so it does notclot properly.clot properly.


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Section 8Section 8

Blood DisordersBlood Disorders


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AnemiasAnemias are red blood cell disorders.are red blood cell disorders.

AnemiasAnemias develop when red blood cells deliverdevelop when red blood cells deliver

too little oxygen to the tissues.too little oxygen to the tissues.

TwoTwo common typescommon types result from nutrientresult from nutrientdeficiencies:deficiencies:

InIn ironiron--deficiencyanemiadeficiencyanemia, red cells contain too little, red cells contain too little

hemoglobin, usually resulting from an ironhemoglobin, usually resulting from an iron--poor diet.poor diet.

Pernicious anemiaPernicious anemia is caused by a deficiency of folicis caused by a deficiency of folicacid or vitamin Bacid or vitamin B1212..

AplasticAplastic anemiaanemia results from a destruction ofresults from a destruction of

the red bone marrow and its stem cells.the red bone marrow and its stem cells.



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Hemolytic anemiasHemolytic anemias areare

caused by the prematurecaused by the premature

destruction of red blood cells.destruction of red blood cells.

Sickle cell anemiaSickle cell anemia, a genetic, a geneticdisease, is one cause.disease, is one cause.

MalariaMalaria is a major cause ofis a major cause of

hemolytic anemia and followshemolytic anemia and follows

infection by a protozoaninfection by a protozoantransmitted by mosquitoes.transmitted by mosquitoes.

InIn thalassemiathalassemia, individuals produce abnormal, individuals produce abnormal

hemoglobin.hemoglobin.


Figure 8.10Figure 8.10


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Carbon monoxide poisoning preventsCarbon monoxide poisoning prevents

hemoglobin from binding oxygen.hemoglobin from binding oxygen.

Carbon monoxide (CO) is a colorless, odorlessCarbon monoxide (CO) is a colorless, odorless

gas present in auto exhaust fumes and smokegas present in auto exhaust fumes and smokefrom wood, coal, charcoal, andfrom wood, coal, charcoal, and tobacco.tobacco.

COCO binds to hemoglobin 200 times more tightlybinds to hemoglobin 200 times more tightly

than oxygen, thus blocking oxygen transport tothan oxygen, thus blocking oxygen transport to

tissues.tissues. Feeling faint near auto exhaust is a badFeeling faint near auto exhaust is a badsign! Get some fresh air or you could faint andsign! Get some fresh air or you could faint and

diedie!!

Cigarette smoke has CO too (dont smoke!).Cigarette smoke has CO too (dont smoke!).



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Mononucleosis andMononucleosis and leukemiasleukemias affect whiteaffect white

blood cells.blood cells.

Infectious mononucleosisInfectious mononucleosis is caused by theis caused by the

EpsteinEpstein--Barr virus, which triggersBarr virus, which triggersoverproduction of lymphocytesoverproduction of lymphocytes. Patient feels. Patient feels

achy and tired and runs a fever for severalachy and tired and runs a fever for several

weeks.weeks.

LeukemiasLeukemias are very serious cancers in whichare very serious cancers in whichthere is an overproduction of white blood cellsthere is an overproduction of white blood cells

and destruction of boneand destruction of bone marrow.marrow.



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chapter 8 -blood

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