Presentation on theme: "Functions of Blood Deliver O2, nutrients to all body cells"— Presentation transcript:
1 Functions of Blood Deliver O2, nutrients to all body cells Transport waste products from cells for eliminationTransport hormonesMaintain body temp (distribute heat)Maintain pH (carry buffers)Maintain fluid volumePrevent blood loss (clotting)Prevent infection (WBCs, antibodies)
2 Blood Components Plasma (55%) water (90%), ions, proteins, gases, nutrients, wastes, hormonesCells (45%)RBCs, WBCs, plateletsDevelop from stem cells in bone marrow
4 Blood Cell Formation Hematopoiesis: blood cell formation Occurs in red bone marrowSkull, pelvis, ribs, sternum, humerus, femur
5 Erythrocytes Red blood cells (RBCs) Transport O2 in blood Biconcave discsAnucleate (no nucleus)Hemoglobin: iron-containing protein, binds to O2Life span: days
6 Anemia: decrease in oxygen-carrying ability of blood Low RBC count or deficient hemoglobin contentSickle-Cell Disease: abnormal hemoglobinGenetic disorderCarriers of 1 allele are resistant to malaria in Africa
8 Leukocytes White blood cells (WBCs) Defend body against infection and tumorsLocate areas of tissue damage by responding to chemicalsTypes: neutrophils, eosinophils, basophils, lymphocytes, monocytes
9 Leukemia: bone marrow becomes cancerous huge numbers of WBCs Treatment: chemotherapy, radiation, stem cell transplant
10 Platelets Cell fragments (irregularly-shaped bodies) Needed for clotting blood
11 Hemostasis = stoppage of bleeding Vascular spasmConstrict damaged blood vesselsPlatelet plug formsPlatelets stick and bind to damaged siteRelease chemicals to attract more plateletsCoagulationBlood clottingFibrin threads forms mesh that traps RBCsTime: blood clot normally forms within 3-6 min.
15 Human Blood GroupsAntigen: foreign substance that immune system recognizesAntibodies: Y-shaped proteins secreted by WBC’s that attach to antigensAgglutination: clumping caused by antibodies binding to antigens on RBCsRBC surface proteins:A antigenB antigenRh antigen
16 ABO Blood Groups42%12%3%43%Type A: has A antigen on surface of RBCType B: has B antigenType AB: has both A & B antigensType O: has no antigens on surface
17 Rh antigen found on RBC’s in Rhesus monkeys (1940)
41 Warm-UpDraw the human heart and the main blood vessels in/out of the heart.Label the following on your diagram:4 chambers4 valvesAll blood vessels going into/out of heartUsing a blue pencil, indicate oxygen-poor blood flowUsing a red pencil, indicate oxygen-rich blood flow
43 Heart RhythmCardiac muscle cells can contract spontaneously and independentlyRegulation of heart activity:Autonomic nervous systemEpinephrine, thyroxine: heart rateLow Ca2+ levels: heart rateIntrinsic conduction systemBuilt into heart tissue & sets basic rhythmPacemaker = Sinoatrial (SA) Node
44 Intrinsic conduction system Sequence of action:Sinoatrial (SA) node – right atriumGenerates impulses Starts each heartbeatAtrioventricular (AV) node – between atria & ventriclesAtria contractBundle of His (or AV bundle)Bundle branches – interventricular septumPurkinje fibers – spread within ventricle wallsVentricles contract
52 Cardiac Cycle Cardiac cycle = events of one heartbeat Systole: contraction of ventriclesDiastole: relaxation of ventriclesCardiac Output Animation
53 Heart Sounds “Lub”: closing of AV valves “Dub”: semilunar valves close at end of systole
54 Homeostatic Imbalances Angina pectoris: heart muscle deprived of O2,crushing chest painMyocardial infarction (Heart Attack): prolonged angina, heart cells may die
55 Homeostatic Imbalances Ischemia: Lack of adequate blood supply to heartFibrillation: uncoordinated shuddering of heart muscle, useless pumpMajor cause of death from heart attacks
56 Homeostatic Imbalances Damage to SA node slower heart rateInstall artificial pacemakerDamage to AV node Heart block: ventricles beat at own rate (slower or not at all)Tachycardia: rapid heart rate (>100 beats/min)Bradycardia: very slow heart rate (<60 beats/min)Heart murmur: abnormal or unusual heart soundsOften valve problems
57 Cardiac Output CO = HR (75 beats/min) x SV (70 ml/beat) Cardiac Output (CO) = Heart Rate (HR) x Stroke Volume (SV)Stroke volume: volume of blood pumped out by one ventricle with each bestAverage adult:CO = HR (75 beats/min) x SV (70 ml/beat)CO = 5250 ml/min
60 Warm-Up What is the pacemaker? Where is it located? List the parts of the intrinsic conduction system of the heart.Draw and label the 3 waves of a typical EKG tracing. What is happening at each wave?What causes the heart sounds (lub-dub)?
61 Warm-Up Compare arteries, capillaries, & veins. Imagine you are a red blood cell. List the pathway you would travel through the body in a complete circuit starting at a pinky toe.Explain how blood pressure is measured.
62 Warm-Up What is hypertension? What are possible causes? What is atherosclerosis?What can you do to prevent atherosclerosis?What treatment options are available for patients with coronary atherosclerosis?
67 Arteries Capillaries Veins Blood away from heart Thicker walls Withstand high pressureWalls 1-cell thickExchange gases between blood and tissue cellsBlood back to heartThinner wallsLow pressureLarge lumenValves: prevent blood backflowSkeletal muscles enhance venous return
68 Vericose VeinsPeople stand for long periods of time inactivity or pressure on veinsBlood pools in feet and legsValves weaken veins become twisted & dilatedTreatment: compression stockings, exercise, laser treatment, surgery
69 Vital SignsPulse: expansion & recoil of an artery with each beat of left ventriclePressure points (eg. carotid artery, radial artery)Normal resting: beats/min
70 Vital SignsBlood pressure: pressure of blood on inner walls of blood vesselsSystolic presure: peak of ventricular contractionDiastolic pressure: ventricles relaxedWritten: Systolic/DiastolicNormal: (120 mm Hg)/(70 mm Hg) or 120/70
73 Using a sphygmomanometer Wrap cuff around upper armPlace stethoscope on brachial arteryInflate cuff to 180 mm HgSlowly release air listen for whooshing sounds in brachial artery (Korotkoff sounds)Systolic: when sound begin to appearDiastolic: when sounds disappear