Chapter 11 The Cardiovascular System: Blood

11-1: Blood Characteristics BloodBlood—connective tissue containing cells suspended in fluid matrix Functions –Transport gases, nutrients, hormones & waste –Regulate pH & ions –Restrict fluid loss at injury sites –Defend against toxins & pathogens –Stabilize body temp

Composition of Blood plasma formed elementsMade of plasma & formed elements pH: 7.35 – 7.45; volume: males 5 – 6 L, females 4 – 5 L Blood Collection & Analysis venipunctureBlood collected through venipuncture blood smearBlood can be used to prepare blood smear to show different formed elements

11-1 Checkpoint 1.List five major functions of blood. 2.What two components make up whole blood? 3.Why is venipuncture a common technique for obtaining a blood sample?

11-2: Plasma Composition of Plasma Blood is 55% plasma –Composed of plasma proteins, solutes & water Plasma Proteins Types of plasma proteins –Albumins –Albumins—majority of plasma; maintain pressure –Globulins –Globulins—antibodies & transport proteins –Fibrinogens –Fibrinogens—blood clotting

11-2 Checkpoint 1.List the three major types of plasma proteins. 2.What would be the effects of a decrease in the amount of plasma proteins?

11-3: Red Blood Cells (RBCs) Abundance of RBCs erythrocytesBlood is 45% RBCs (erythrocytes) HematocritHematocrit—percentage of whole blood volume occupied by formed elements –99.9% RBCs, <0.1% WBCs, <0.1% platelets Structure of RBCs RBC is biconcave disc, lacks a nucleus

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Hemoglobin Structure & Function HemoglobinHemoglobin in RBC transports O 2 & CO 2 heme –4 heme subunits bind with iron Hemoglobin binding process –Lungs: hemoglobin binds to O 2, releases CO 2 –Tissues: hemoglobin binds to CO 2, releases O 2 AnemiaAnemia—RBCs have reduced hemoglobin content –Iron-deficiency anemia –Iron-deficiency anemia more common in women

RBC Life Span & Circulation RBCs last about 120 days Hemoglobin recycling –Hemolysis –Hemolysis: RBC ruptures –Phagocytosis –Phagocytosis: Macrophages in body engulf RBCs, hemoglobin broken apart into heme & recycled by body bilirubinHeme converted to bilirubin (yellow pigment) jaundice –Excess bilirubin causes jaundice

RBC Formation ErythropoiesisErythropoiesis—formation of RBCs red bone marrow –Occurs in red bone marrow Erythropoiesis requires amino acids, iron & vitamins Erythropoietin (EPO) hypoxiaErythropoietin (EPO) released during low O 2 levels (hypoxia) –Stimulates cell division in bone marrow –Speeds RBC maturation

11-3 Checkpoint 1.Describe hemoglobin. 2.What effect does dehydration have on an individual’s hematocrit? 3.What effect does a reduction in oxygen supply to the kidneys have on levels of EPO in the blood?

11-4: ABO Blood Types antigens immune responseSurface antigens trigger immune response Presence/absence of antigens determines blood type blood type –Type A –Type A—antigen A only –Type B –Type B—antigen B only –Type AB –Type AB—antigens A & B –Type O –Type O—no antigens –Rh positive –Rh positive—Rh antigen present –Rh negative –Rh negative—Rh antigen absent

Cross-Reactions in Transfusions Antibodies attack foreign antigens on RBCs Type A bloodType A blood Antigen A –Antigen: Antigen A Anti-B –Antibody: Anti-B AOBAB –Can receive type A & O blood, not B or AB Type B bloodType B blood Antigen B –Antigen: Antigen B Anti-A –Antibody: Anti-A BOAAB –Can receive type B & O blood, not A or AB

Type AB bloodType AB blood Antigens A & B –Antigen: Antigens A & B no –Antibody: no antibodies universal recipient –Can receive all types of blood—universal recipient Type O bloodType O blood no –Antigen: no antigens Anti-AAnti-B –Antibodies: Anti-A & Anti-B universaldonor –Can be given to people with any blood type— universal donor O –Can only receive type O blood

cross-reaction (transfusion reaction)Surface antigens + antibodies from incorrect blood = cross-reaction (transfusion reaction) AgglutinationAgglutination—clumping of antigens & antibodies

Rh Blood Group Interactions Rh - person receives Rh + blood: anti-Rh antibodiesImmune system produces anti-Rh antibodies No reaction until next transfusion Rh - mother delivers Rh + baby Placenta causes blood to mix Anti-Rh antibodiesAnti-Rh antibodies formed erythroblastosisfetalisNext Rh + baby attacked by anti-Rh antibodies—erythroblastosis fetalis Copyright  The McGraw-Hill Companies, Inc. Permission required for reproduction or display

11-4 Checkpoint 1.Which blood type(s) can be safely transfused into a person with Type AB blood? 2.Why can’t a person with Type A blood safely receive blood from a person with Type B blood?

11-5: White Blood Cells (WBCs) leukocytesWBCs (leukocytes) larger than RBCs, have a nucleus Defend the body against pathogens; remove toxins, wastes, abnormal or damaged cells Compose <0.1% of hematocrit

WBC Circulation & Movement Characteristics of WBC movement: –Amoeboid movement –Amoeboid movement—extend cytoplasm to move –Diapedesis –Diapedesis—squeeze through capillary cells to exit bloodstream –Positive chemotaxis –Positive chemotaxis—attracted to chemical stimuli phagocytosis –Capable of phagocytosis—engulf pathogens or other materials

Types of WBCs NeutrophilsNeutrophils –Most numerous WBC –Attack & digest bacteria EosinophilsEosinophils –Attack objects coated with antibodies BasophilsBasophils heparin histamine –Release heparin (blood clotting) & histamine (inflammation

MonocytesMonocytes –Attack large objects, release chemicals to attract other WBCs LymphocytesLymphocytes –Continuously migrate through body –Attack foreign cells (crucial in immunity)

Differential Count of WBCs Differential countDifferential count—indicates number of each type of cell –Determines presence of infections, disorders LeukopeniaLeukopenia—reduced number of WBCs LeukocytosisLeukocytosis—excessive numbers of WBCs leukemia –Extreme leukocytosis indicates leukemia

11-5 Checkpoint 1.Identify the five types of WBCs. 2.Which type of cell would you find in elevated numbers in a person producing large amounts of circulating antibodies to combat a virus?

11-6: Platelets PlateletsPlatelets—cell fragments –Compose <0.1% of hematocrit MegakaryocytesMegakaryocytes release platelets into bloodstream –Initiate clotting process Thrombocytopenia thrombocytosisThrombocytopenia (low platelet number) & thrombocytosis (high platelet number)

11-6 Checkpoint 1.Explain how platelets form. 2.List the primary functions of platelets

11-7: Hemostasis HemostasisHemostasis—process that halts bleeding & prevents loss of blood Phases of Hemostasis Vascular phaseVascular phase vascular spasm –Cut blood vessel triggers vascular spasm (contraction) –Blood flow from small vessels slowed or stopped

Platelet phasePlatelet phase –Platelets attach to inner blood vessel & mesh of collagen fibers platelet plug –Forms a platelet plug to close break Coagulation phase blood clottingCoagulation phase (blood clotting) –Protein mesh grows, traps blood cells & platelets –Uses clotting factors to aid in clotting process –Blood clot –Blood clot seals off damaged vessel

Clot Retraction & Removal Clot retractionClot retraction—platelets contract to pull edges of wound closer together FibrinolysisFibrinolysis—dissolves clot –Plasminogen tissueplasminogen activator (t-Pa) –Plasminogen & tissue plasminogen activator (t-Pa) digest protein strands t-Pa used in treatment of strokes

Abnormal Hemostasis ThrombusThrombus—large blood clot attached to vessel wall EmbolusEmbolus—drifting blood clot in the bloodstream embolism –Can result in an embolism—blockage of blood vessel due to embolus HemophiliaHemophilia—inadequate production of clotting factors

11-7 Checkpoint 1.If a sample of red bone marrow has fewer than normal megakaryocytes, what body process would you expect to be impaired as a result? 2.What are the phases of hemostasis? 3.How is a thrombus different from an embolus?