14 Unit 1 Chapter 14. 14 Unit 1 3 components of the cardiovascular system = blood, heart, blood...

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The Cardiovascular The Cardiovascular System: BloodSystem: Blood

The Cardiovascular The Cardiovascular System: BloodSystem: Blood

Chapter 14

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FunctionFunctionFunctionFunction

• 3 components of the cardiovascular system = blood, heart, blood vessels

• Function of CV system = transports substances to and from body cells

• Hematology = branch of science that deals with study of blood, blood-forming tissues and disorders associated with them

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Functions of BloodFunctions of BloodFunctions of BloodFunctions of Blood

• Is a type of connective tissue

• Transportation- gasses (O2 & CO2), nutrients (GI tract), heat & waste, hormones (endocrine system)

• Regulation- pH, temperature, water balance in cells

• Protection- loss of blood via clotting, WBC vs. disease; production of interferons and complement

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Components Components Components Components

• 5 facts about blood1.Blood is thicker than water 2.Temp is 38° C3.Slightly alkaline 7.35 – 7.454.8% of total body weight5.Volume = males – 5-6 liters females – 4-5 liters

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CompositionCompositionCompositionComposition

• Connective tissue-Two parts• Plasma = straw-colored liquid

with dissolved materials (~55%)

• Formed Elements = cells and cells fragments (~45%) 99% of the formed elements are RBCs

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CompositionCompositionCompositionComposition

• hematocrit (Hct) = Percent of blood volume occupied by red blood cells (RBC)

• Buffy coat – part made up by white blood cells (WBC) and plateletes ~1%

Figure 14.1aFigure 14.1a

Figure 14.1bFigure 14.1b

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PlasmaPlasmaPlasmaPlasma

• ~91% water, 7% proteins, 1.5 % other solutes

• Proteins: Albumin (54%)- maintains osmotic pressure;

• Globulins (38%)- antibodies for defense

• Fibrinogen (7%)- clotting• Other solutes in plasma: Electrolytes ,

nutrients, gases, hormones, vitamins & waste products

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Formed ElementsFormed ElementsFormed ElementsFormed Elements

I. Red Blood CellsII. White blood cells

A. granular Leukocytes1. Neutrophils2. Eosinophils3. Basophils

B. Agranular leukocytes1. T & B lymphocytes & natural Killer cells2. monocytes

III Platelets

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Formation of Red Blood Formation of Red Blood CellsCells


• Hemopoiesis – production of formed elements

• 3 months before birth and throughout life occurs in red bone marrow

• Contains pluripotent stem cells• In response to specific hormones

these develop through a series of changes to form all of the blood cells

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• Bone marrow contains pluripotent stem cells – cells that can develop into many different types of cells

• In response to specific hormones these develop into myeloid stem cells (RBC, platelets, and some WBC) and lymphoid stem cells (T and B lymphocytes)

Figure 14.2aFigure 14.2a

Figure 14.2bFigure 14.2b

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Red Blood CellsRed Blood Cells Red Blood CellsRed Blood Cells

•AKA = Erythrocytes•Contains - hemoglobin

protein- carries oxygenAlso carries some CO2

•Male has ~ 5.4 million cells/µl; Female has ~4.8 million

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Erythrocytes (RBCs)Erythrocytes (RBCs)Erythrocytes (RBCs)Erythrocytes (RBCs)

• Production rate = 2 million/sec• Contain no nucleus & other

organelles• Consists of membrane, cytosol,

hemoglobin• Biconcave shape provides for

greater surface area for the diffusion of gas molecules into/out of a RBC

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RBC CyclingRBC CyclingRBC CyclingRBC Cycling

• Wear out fast- live ~120 days due to wear and tear as they squeeze through capillaries

• Worn out and ruptured cells are cleared by macrophages (liver spleen, red bone marrow)

• Fe- recycled in bone marrowCarried in blood on transferrin – plasma

protein acts as a transporter for iron

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RBC CyclingRBC CyclingRBC CyclingRBC Cycling

• biliverdin bilirubin – what the non-iron portion of heme is converted into and excreted (bile)

• Urobilinogen and stercobilin – by products of bilirubin; some absorbed in large intestine; ultimately excreted in urine or feces

Figure 14.3Figure 14.3

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RBC ProductionRBC ProductionRBC ProductionRBC Production

•called erythropoiesis•Released as reticulocytes

(almost a RBC)Mature to erythrocytes in 1-2 days

•Production & destruction is balanced

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RBC SynthesisRBC SynthesisRBC SynthesisRBC Synthesis

•If O2 carrying capacity falls, RBC productions is inc. by a negative feedback loop

•Low O2 delivery (hypoxia)

•erythropoietin (EPO)- kidney hormone stimulates erythropoiesis

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RBC SynthesisRBC SynthesisRBC SynthesisRBC Synthesis

•Cyanosis – life threatening condition caused by prolonged hypoxia; bluish-purple skin coloration

•Anemia – reduced O2 carrying capacity – reduced # of RBC or ↓ amount of hemoglobin in blood; pale skin

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White Blood CellsWhite Blood CellsWhite Blood CellsWhite Blood Cells

• aka = leukocytes• Classified as either 1. granular

which contains a chemical filled cytoplasmic granule/vesicle (neutrophils, eosinophils, basophils) or 2. agranular (lymphocytes, monocytes)

• Function in defense: phagocytosis or antibody production

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• Phagocytes:Neutrophil- first responders; release

lysozomes that destroy bacteriaMonocytes slower response; become

wandering macrophages (big eaters compared to neutrophils)

Eosinophil- work in interstitial fluid; Involved in suppressing allergic responses; phagocitize antibody-antigen complexes and are effective against some parasitic worms

Basophil- intensify allergic reactions

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•Phagocytes:a. Neutrophil- first responders;

release lysozomes that destroy bacteria

b. Monocytes slower response; become wandering macrophages (big eaters compared to neutrophils)

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• Phagocytes:c. Eosinophil- phagocitize antibody-antigen complexes involved in suppressing allergic responses

d. Basophil- release heparin, histamines, serotonin; intensify allergic reactions

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• Producing antibodies (Immune response):B-cells – plasma cells – produce

antibodies to help destroy bacteria/inactivate toxins

T-cells – attack viruses, fungi, cancer cells, transplanted cells, bacterial cells

Natural killer (NK) cells – attack infectious microbes and some types of tumor cells

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• Major histocompatibility (MHC) antigens – proteins on the surface of a cells that act as “cell identity markers” that are unique for each person; used to type tissue for transplants

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WBC Life SpanWBC Life SpanWBC Life SpanWBC Life Span

• Number of RBC vs. WBC is 700:1; 5000-10,000 WBC /µl blood

• Life span is a few days normally; a few hour during an active infection; some B and T cells live for years

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WBC Life SpanWBC Life SpanWBC Life SpanWBC Life Span

•Leukocytosis= normal increase in WBC #’s response to stresses; indicates inflammtion/infection

• Differential white blood cell count is the measure of the different types of WBC per 100 WBC (helps in diagnosis)

•Leukopenia = abnormally low WBC numbers; never good; radiation, shock, some chemotherapeutic agents

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PlateletsPlateletsPlateletsPlatelets

• Myeloid stem cells megakaryoblasts megakaryocytes 2000 -3000 fragments = platelets

• Plug damaged blood vessels• Promote blood clotting• Life span 5-9 days

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HemostasisHemostasisHemostasisHemostasis

• Hemostasis = stationary blood – a series of responses that stop bleeding when blood vessels are injured

1. Vascular reactions (spasm) 2. platelet plug formation3. blood clotting (coagulation)

• Hemorrhage - loss of large amounts of blood

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• 1. Vascular spasm – contraction of smooth muscle in the walls of a damaged blood vessel; effective for several minutes to several hours; platelets at the site release chemicals to enhance vasoconstriction maintaining vascular spasmQuick reduction of blood loss

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• 2. platelet plug formation – platelets stick to parts of a damaged blood vessel; they release chemcials to make other platelets sticky; eventually forms a platelet plug

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• 3. blood clotting –when blood is withdrawn it separates into serum and a gel called fibrin (protein fibers that make up a clots)

• Clotting (coagulation) –process of clot formation; series of chemical reactions involving clotting factors

• Thrombosis – clotting in an unbroken blood vessel

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3 Stages of Clotting 3 Stages of Clotting 3 Stages of Clotting 3 Stages of Clotting

• 1. prothrombinase is formed• 2. prothrombinase converts

prothrombin (a protein) thrombin (an enzyme)

• 3. thrombin converts fibrinogen (another protein) fibrin (fibers that form the threads of a clot) clot

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Prothrombinase Prothrombinase FormationFormation

Prothrombinase Prothrombinase FormationFormation

• Extrinsic pathway happens quickly;tissue factor(TF) from damaged

cells makes prothrombinase

• Intrinsic Pathway takes several minutes Materials “intrinsic” to blood make

prothrombinase

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Clot Retraction & Vessel Clot Retraction & Vessel RepairRepair

Clot Retraction & Vessel Clot Retraction & Vessel RepairRepair

• Clot retraction- consolidation or tightening of the fibrin clot

• As the clot retracts damaged edges of blood vessels pull closer together

• Permanent repairs take place when fibroblasts form connective tissue and endothelial cells repair the vessel lining

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Control MechanismsControl MechanismsControl MechanismsControl Mechanisms

•Fibrinolysis: dissolving of unnecessary clots by activated plasmin which digests fibrin threads in a clot

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Clotting in Blood VesselsClotting in Blood VesselsClotting in Blood VesselsClotting in Blood Vessels

• Clots can be triggered by 1. Roughness on vessel wall as a

result of atherosclerosis, trauma, infection

2. If the flow of blood becomes too slow clotting factors accumulate enough to trigger a clot

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Control MechanismsControl MechanismsControl MechanismsControl Mechanisms

•Thrombosis - clotting in an unbroken vessel (thrombus = clot)

• Blood clot, air bubble, or fat from a broken bone transported by blood= embolus and can block a small blood vessel

•Pulmonary embolism – blockage of blood vessel in the lungs

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Blood Group and TypesBlood Group and TypesBlood Group and TypesBlood Group and Types

• Agglutinogens – antigens composed of glycolipids/proteins on the surface of RBC

• Blood groups are categorized based on the presence or absence of various antigens

• >24 blood groups and >100 antigens

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Blood TypesBlood TypesBlood TypesBlood Types

• We will deal with ABO and Rh groups

• ABO blood group has two antigens A and B

• Your blood type is determined by which you have (if you have the A antigen you have blood type A; AB blood has both the A and B antigen; O has no antigen)

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ABO GroupABO GroupABO GroupABO Group

• Blood usually has antibodies or agglutinins that can react with antigense.g. anti-A antibody or anti-B

antibody• You don’t react with your own

antigensThus: type A has anti-B and vice

versa

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Rh Blood GroupRh Blood GroupRh Blood GroupRh Blood Group

• The Rh blood group is named after the rhesus monkey where the Rh antigen was discovered

• If have antigen you are Rh+

• Normally we don’t have anti-Rh antibodies they develop after the first exposure from transfusion

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TransfusionsTransfusionsTransfusionsTransfusions

• Transfusion – transfer of whole blood or blood components (plasma)

• If mismatched blood is given antibodies in the recipient's blood bind to the antigens on the donated RBC and causes hemolysis (rupture of RBC)

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TransfusionsTransfusionsTransfusionsTransfusions

• Universal recipients - Type AB has no AB antibodies so can receive any ABO type blood

• Universal donors - Type O have neither antigen so can donate to any other ABO type

• Misleading because of many other blood groups that must be matched

14 Unit 1 Chapter 14. 14 Unit 1 3 components of the cardiovascular system = blood, heart, blood...

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Transcript of 14 Unit 1 Chapter 14. 14 Unit 1 3 components of the cardiovascular system = blood, heart, blood...