Cardiovascular System

Blood1. FunctionsA) transportation of nutrients & wasteB) regulation of pH & body temperatureC) protection from blood loss & foreign invasion2. CharacteristicsA) liquid connective tissueB) 8% of human body weightBloodC) 4-5 times more viscous than waterD) NaCl conc. of 0.85-0.9%E) pH ranges from 7.35-7.45F) total blood volume varies1) 5-6L for males2) 4-5L for femalesBloodG) Components1) plasma (55%)a) about 90-92% waterb) contains nutrients & wastesc) contains plasma proteinsd) serum Blood2) formed elements (45%)a) erythrocytesb) leukocytesc) platelets (thrombocytes)Blood3. Red Blood Cells (erythrocytes)A) biconcave1) created by spectrin2) greater surface area3) flexibleB) anucleateC) contain hemoglobin (~280 million molecules/RBC)

Blood1) globin protein composed of 4 polypeptide chains each containing a heme groupa) Fe++D) Normal RBC counts: (1 drop ~50mm3) males = 4.76.1 mil/mm3 females = 4.25.4 mil/mm3 children = 4.6 4.8 mil/mm3 BloodE) new cells produced at rate of ~2 mil/sec, live ~120 days1) controlled by erythropoietinBloodF) Erythrocytic Disorders1) Anemiaa) Aplastic anemia faulty bone marrowi) often caused by radiation, drug use, bacterial toxins, some poisons, and some antibioticsb) Pernicious anemia decreased B12 (necessary for RBC production)c) Hemolytic anemiaBloodd) Hemorrhagic anemiae) Iron-deficiency anemiai) results in microcytesf) Sickle-cell anemiai) genetic defect causes one globin chain to become rigidBloodg) Thalassemiai) genetic defect resulting in absent or faulty globin chain2) Polycythemiaa) primary polycythemia (polycythemia vera)b) secondary polycythemiac) blood-dopingBloodG) Erythropoiesis1) hemocytoblast2) proerythroblast3) early erythroblast4) late erythroblastBlood5) normoblast accumulate hemoglobin and eject organelles6) reticulocyte enter circulation and carry O2; continue to lose organelles7) erythrocyte (RBC)Blood4. White Blood Cells (leukocytes)A) ~5,000 - 10,000/mm3; live a few daysB) diapedisis1) amoeboid motion process by which diapedisis occursC) There are 5 types of WBC broken down into 2 categories1) granulocytes (granular WBC)Blooda) neutrophils (polymorphonuclear leukocytes) (50-70%)i) numerous fine granules which stain pale lilac w/ a darker multi-lobed nucleusii) phagocytes

Bloodb) basophils (0.5-1%)i) purpleish-black granules that often obscure a bilobed nucleusii) intensify inflammation and allergic reactions

Bloodiii) chemicals released include histamine, heparin, leukotrienes, and prostaglandinsiv) were once thought to develop into mast cells(a) have identical functions except mast cells are only found outside the bloodstreamBloodc) eosinophils (2-4%)i) distinct red granules; bilobed nucleusii) combat parasitic worms & inflammation

Blood2) agranulocytes a) monocytes (3-8%)i) pale-blue cytoplasm w/ U or kidney shaped nucleusii) develop into macrophages once in tissueiii) phagocytes

Bloodb) lymphocytes (20-25%)i) large, dark-purple nucleus occupies most of the cellii) fight infection, produce antibodies, and provide immunity

Bloodiii) 3 types(a) B lymphocytes(i) attack bacteria & their toxins(ii) develop into plasma cells which release antibodiesBlood(b) T lymphocytes (i) attack viruses, fungi, cancer cells, transplanted cells, & some bacteria(ii) work w/ B cells to provide immunity(c) natural killer cells(i) attack a wide variety of microbes w/o much specificityBloodD) Leukocytic Disorders1) leukopenia decreased WBC counta) often caused by gluccocorticoids and various cancer & HIV drugs2) leukocytosis increased WBC counta) often caused by acute infections, inflammation, or hemorrhage3) infectious mononucleosisa) caused by Epstein-Barr virusBlood4) Leukemiaa) group of cancerous conditions involving WBCb) may be named for cells affectedi) ex. myelocytic leukemia or lymphocytic leukemiac) may be named for the WBCs stagei) ex. acute leukemia or chronic leukemiaBloodE) Leukopoiesis 1) stimulated by interlukins (IL) & colony-stimulating factors (CSF)2) multiple pathways but all start w/ hemocytoblasts in red bone marrowa) monoblasti) promonocyteii) monocyteBloodb) lymphoblasti) prolymphocyteii) lymphocytec) myeloblasti) promyelocyteii) myelocyte(a) eosinophilic, basophilic or neutrophilicBloodiii) band cell(a) eosinophilic, basophilic or neutrophiliciv) eosinophil, basophil or neutrophil5. PlateletsA) ~250,000 - 400,000/mm3, live 5-9 daysB) stop blood loss 3 mechanismsBlood1) vascular spasma) vasoconstrictionb) can last minutes hours2) platelet plug formationa) triggered by von Willebrand factor (VWF)i) adhere to exposed collagen fibersii) activates plateletsBloodb) platelet adhesioni) initial sticking of platelets to the wound siteii) activates more plateletsc) platelet aggregationd) platelet plug3) coagulation (blood clotting)a) involves over 30 different chemicals including:Bloodi) 13 different clotting factorsii) Vitamin Kiii) Ca++b) prothrombin activator (enzyme) is formed following the coming together of various clotting factorsc) prothrombin activator converts prothrombin (plasma protein) to thrombin (enzyme)Bloodd) thrombin converts fibrinogen (plasma protein) to fibrin (fibers of the clot)e) formed elements become trapped in fibrinf) serum filters outi) clot resultsg) clot retractionh) fibrinolysisBloodC) Thrombopoiesis1) stimulated by thrombopoietina) hemocytoblastb) megakaryoblastc) promegakaryocyted) megakaryocytei) ruptures as it enters circulatione) plateletBloodD) Clotting Disorders1) thrombus a clot in a healthy vessel2) embolus a thrombus that has broken free and entered circulation3) embolism when an embolus becomes trapped in another vessel; can lead to death if it occurs in the heart or lungsBlood4) hemophilia an inability of the blood to clot properlya) sex-linked disorder5) thrombocytopeniaa) decreased platelet countb) caused by any condition that suppresses or destroys bone marrowBlood6. Blood TypingA) based on presence/absence of specific antigensB) ABO Groups1) determined by the presence or absence of antigens A & Ba) Type A blood has only antigen Ab) Type B blood has only antigen BBloodc) Type AB blood has antigens A & Bd) Type O blood has neither antigen2) Blood also contain antibodies for the antigen(s) the RBC dont havea) Type A blood has B antibodiesb) Type B blood has A antibodiesc) Type AB blood has no antibodiesd) Type O blood has A & B antibodiesBloodD) Rh Group1) refers to the presence or absence of Rh antigens (there are at least 45 different ones)a) Rh+ has at least one Rh antigenb) Rh- has no Rh antigens2) antibodies are not present for Rh antigen unless conflicting blood is introducedBlooda) first exposure no immune response (rejection)b) subsequent exposures will result in an immune response (rejection)E) Transfusions1) if the body sees a foreign antigen it will attack the RBC causing them to clump together 2) always try to match blood typesBlood3) some exceptions can be madea) Type O is the universal donorb) Type AB is the universal recipient4) Complicationsa) clumping in small vesselsb) RBC are destroyed by immune system releasing hemoglobinc) flu-like symptoms are commonBloodBlood TypeAntigens PresentAntibodies PresentCan Receive Blood From:Can Donate Blood To:AABA & OA & ABBBAB & OB & ABABA & BnoneA, B, AB & OAB onlyOnoneA & BO onlyA, B,AB & OBlood5) Hemolytic Disease of the Newborna) Also called Erythroblastosis fetalisb) Results when mother is Rh- and baby is Rh+c) Upon delivery, Rh+ antigens are transferred to the mothers bloodstream which causes her to produce anti-Rh antibodiesBloodd) If the mother becomes pregnant again with an Rh+ child, the antibodies cross the placenta, enter the circulation of the fetus, and cause extensive fetal erythrocyte damage