Chapter 12 Circulatory System

Chapter 12 Circulatory SystemWorkbook AssignmentTrue and False pg 147Key Term Assessment pg 148Evaluation of Learning pg 140 #1-76CrosswordWorkbook and Terminology Book due on the day of the testCirculatory SystemHeart pumpBlood Vessels form the pathway for which blood can flow throughout the body Blood transport medium for nutrients, oxygen, blood cells, etc

FACTSPerfusion: blood flowing throughout the body to supply the tissues and organs with oxygen and nutrientsDecreased blood flow results in organ shut down, loss of brain cells and cardiac muscle cells. Then you dieHeartMuscular PumpStrong enough to pump blood to all the tissues of the body (5 L of blood per minute)Tissues need constant supply of oxygen and nutrients Waste products must be removed regularly or they will build up and cause damageHEART - Size and LocationLocated in the thoracic cavity between the lungs, behind the sternum(posterior) and in front of the spine (anterior)2/3 of the heart lie to the left of the sternumApex pointed end (bottom) Base wider end (top) Size varies with each pt (fist)

PericardiumPericardium double layered sac that encloses the heart, loose fitting

Coverings continuedFibrous pericardium: outer layer of the pericardiumParietal pericardium: membrane that lines the fibrous pericardiumVisceral pericardium: membrane that faces the heart aka: epicardium

Pericardial Cavity: space between the parietal and visceral layers, contains fluid that reduces friction

Layers of the heart wall1. Epicardium: outer layer Thin protective layercontains blood vessels that nourish the heart wall2. Myocardium: middle muscular layerbulk of the heart wall contraction of this muscle forces the blood out of the heart and into the blood vessels3. Endocardium - smooth inner lining heart wallBlood moves easily thru the heart forms the valves of the heart

Heart Chambers Atria : top 2 chambers of the heart -thin walled receiving chambersVentricles: 2 lower chamberslarger and thicker walled - pumping chambers

Right AtriumReceiving chamber deoxygenated blood from the bodySuperior Vena Cava: Returns blood to the heart from the head, neck, & upper extremities.Inferior Vena Cava: Returns blood to the heart from the thorax, abdomen, pelvis & lower extremities.

Left AtriumReceiving chamber oxygenated blood from the lungs through the 4 pulmonary veins

Interatrial Septum - Thin partition that separates the R and L atria

Within the interatrial septum is a fossa ovalis: thinner part of the interatrial septum. In the fetal heart there is an opening called a foramen ovale. Closes after birth on most. Can remain open through adulthood. Referred to as a Patent Foramen Ovale VentriclesR Ventricle: Receives blood from the R atrium and pumps it to the lungs where it receives oxygenL Ventricle: Receives blood from the L atrium and pumps it to the body tissueInterventricular Septum: thick muscular partition between the ventricles

4 Valves of the HeartKeep the fluid moving in one directionHeart has 2 types: Atrioventricular & Semilunar Valves

Mitral Valve

Atrioventricular ValvesPermit the blood to flow through the atria into the corresponding ventriclePrevent backflow of blood from ventricles into atriaTricuspid valve (3) cusps R atrium/R ventricleBicuspid valve (2) cusps L atrium/L ventricle

Semilunar Valves - 2Located at the base of the arteries that carry blood from the ventricles Pulmonary SL valve: exit of the right ventricle in the base of the pulmonary trunkAortic SL valve: exits of the left ventricle and base of the aorta

Pathway of blood through the heartBoth atria contract at the same time followed by both ventriclesRight side of the heart: Pulmonary Circulation pumps blood to the lungs Left side of the heart: Systemic CirculationPumps blood to the body (organs and tissues)Step by Step - Handout1 superior and inferior vena cava,2 to the right atrium4 through the tricuspid valve4 to the right ventricle5 through the pulmonary semilunar valve6 to the pulmonary artery (2) to the lungs - not picturedThe blood picks up oxygen in the lungs, flows back to the heart thru7 pulmonary veins (4) 8 into the left atrium9 through the mitral valve (bicuspid Valve)10 to the left ventricle 11 through the aortic semilunar valve12 to the aortato the body drops off O2 and nutrients and returns with waste through the vena cavas

Video Pathway of blood through the heart http://www.youtube.com/watch?v=JA0Wb3gc4mE

Blood supply to the myocardiumMyocardium muscle layer of the heart needs a constant supply of oxygen and nutrientsTwo arteries that branch off the aorta supply heart muscle with bloodRight and left coronary arteriesCoronary Arteries branch off many times and supply the whole heart with bloodhttp://www.youtube.com/watch?v=LEmifyKuFgE

Angiogramhttp://www.bing.com/videos/search?q=cardiac+angiogram+you+tube&view=detail&mid=D83E420B64E73B87ABFAD83E420B64E73B87ABFA&first=0&qpvt=cardiac+angiogram+you+tube

Function of the Heart - PumpPump blood to the lungs: pulmonary circulationpick up O2 and nutrients Pump blood to the body: systemic circulation to deliver O2 and pick up CO2Blood is pushed around the body by contractions of the heart muscle (myocardium)The conduction system of the heart stimulates the heart to contract and relax at a regular and efficient rate. Components of the Conduction System - 5Sinoatrial Node (SA Node)Located in the right atrium Initiates impulses without neural stimulation Called the hearts natural pacemakerImpulses travel through both atria at the same time causing the atria to contract

Conduction SystemAtrioventricular Node - (AV Node)Located in the floor of the right atrium Receives impulse from the SA node and briefly delays it - gives the atria time to finish contracting before the ventricles begin3. Bundle of HIS 4. Right and Left bundle branches5. Conduction Myofibers (purkinjes fibers)

Purkinje Fibers

http://www.youtube.com/watch?v=fznchh3x54cCardiac CycleConsists of one complete heartbeat Both atria contract at the same timeAtria rest while the ventricles contract at the same timeSystole: contraction phase of the chambersDiastole: relaxation phase of the chambersSystole and DiastoleAtrial Systole contraction of the atria Ventricles are in diastole (relaxed and filling)Ventricular Systole contraction of the ventriclesAtria are in diastole (relaxed and filling) While the Aortic and Pulmonary Vales are closing the physician can hear heart sounds or Lubb-Dubb

BLOODTransport medium (vehicle) for nutrients and oxygen to support the tissues of the body. Removing waste and carbon dioxideComposed of cells and cell fragments suspended in plasma The average adult has (blood volume) Female 4-5 LitersMales 5-6 Liters

Blood Functions: Transportation, Regulation and Protection Transportation: (circulating blood) transports oxygen & nutrients to cellstransports carbon dioxide to the lungs transports waste to the kidneys transports hormonesRegulation:regulates body temperature by removing heat from active areas (skeletal muscle) and transporting it to other areas (skin) regulates fluid and electrolyte balance Function continuedProtection:Clotting mechanism prevent blood loss - plateletsPhagocytic white blood cells engulf bacteria Antibodies help protect against diseaseCells move around the circulatory system in PLASMA (liquid portion of the blood)

Composition of BloodBlood sample centrifuged in the lab separates into 1. cells aka formed elements 2. liquidPlasma is the liquid 55%Buffy Coat - cells Red blood Cells 45%Plasma: 90% water and 10% solutes

10% dissolved solutes Plasma Proteins Albumins Globulins- (lipids and antibodies)FibrinogenElectrolytesSodium, Potassium, Calcium, Chloride, Phosphate, BicarbonateNutrientsAmino acids (protein digestion) Glucose (carbohydrates digestion)Fatty Acids (lipid digestion) Respiratory Gases: (transported as dissolved gasses)OxygenCarbon dioxide

10% solutes contFibrinogenFibrinogen is a soluble plasma protein. When the body is injured, enzymes are released which cause a chemical reaction that changes the fibrinogen into fibrin. Fibrin is insoluble (does not dissolve in water) and forms the foundation of a blood clot.

Formed Elements or cellsErythrocytes Red Blood Cells RBCLeukocytes White blood cells WBCThrombocytes platelets

HematopoiesisProduction of the blood cells - hemocytoblastsBefore birth: in the Liver and the Spleen After birth: red bone marrow of specific bonesHemocytoblast: Stem cell which can develop into 7 different blood cells Hemocytoblast

Erythrocytes (RBC)Most numerous of the formed elementsFemales-4.5 5.5 million Males 4.5 6.2 millionShape: Biconcave shaped discThin in the middle and thicker aroundthe outside. Shape provides flexibility for moving through capillaries and a greater surface area for diffusion of gases

Erythrocytes - RBC Reticulocyte immature RBC with a nucleus. Move from the bone marrow while still immature to the bloodRBC matures it loses its nucleus to create more room on the cell for the hemoglobin. Function of the erythrocyte: transport oxygen and carbon dioxideErythrocyteHemoglobin takes up 1/3 of each erythrocyteTwo parts: Heme and globinHeme: formed from a pigment that contains ironGlobin: protein

Hemoglobin combines with the oxygen in the blood it forms oxyhemoglobin bright redAfter the oxygen is released into the tissues it becomes deoxyhemoglobin darker redHemoglobin

Production of ErythrocytesErythropoietin is a hormone manufactured by the liver and secreted into the blood in an inactive state. When blood oxygen level gets low the kidneys produce REF renal erythropoietic factor which activates the erythropoietin already circulating in the blood, and it stimulates the red bone marrow to increase the production of RBCs. Once 02 levels stabilize, the kidneys decrease the REF and RBC production decreases Production of ErythrocytesIn order for new RBC to be produced, the body must have Iron, Folic Acid and Vitamin B12. The stomach produces Intrinsic factor a protein, so Vitamin B12 can be absorbed. Pernicious Anemia: low RBC count due to Vitamin B12 deficiency (alcoholism, celiac, Charon's)

Destruction of ErythrocytesLifespan of RBC 120 days As the cell ages, the membrane becomes fragile and the cell breaks downMacrophages (phagocytic cells in the spleen and liver) remove them from circulation and new ones are created a the same time. Hemoglobin separates into Heme and globinHeme: bilirubin, yellow bile pigmentglobin: protein broken down into an amino acidLeukocytes - WBCWBCs fight infection. There are 5 types of white blood cells and each fights infection in a special way.WBCs are larger than RBC but fewer in numberNormal WBC 4,500 -11,000Produced from the same hemocyotoblast stem cell but keep their nucleusDo most of their work in the tissues Travel around in the blood and move into tissue spaces by diapedesis: Diapedesis

5 types of LeukocytesGranular and nongranular depending on if they have granules in their cytoplasm. NeutrophilsEosinophilsBasophilsLymphocytesMonocytes(Phils are grainy) Granular LeukocytesNeutrophils: most common 50-70% very grainy cytoplasm with a purple multilobed nucleus stains violet pink first responders to tissue damagework by engulfing bacteria by PhagocytosisBANDS immature neutrophilsNumber Bands and neutrophils increaseduring acute infections

Granular LeukocytesEosinophil: Segmented nucleus 1 or 2Large granules in cytoplasm stains bright reddish orangeNeutralize histamine Multiply during allergic reactions

Granular LeukocytesBasophils: least numerousS shaped nucleus Large coarse granulesStain bluish blackSecrete histamine and heparin (anticoagulant)

Nongranular LeukocytesLymphocytesLarge round or dented nucleusStains deep, purplish blueProduce antibodiesNumbers increase with viruses

Non Granular LeukocytesMonocyte: while still circulatingLargest WBCU shaped/Kidney shaped nucleusStains grayish blue

Macrophages: enters the tissue Finish clean up after neutrophils

Thrombocytes (platelets)Function: close breaks in the blood vesselsAfter injury, become sticky and clump together to form platelet plug which starts the formation of a clot

HemostasisThe stoppage of bleedingThree phases: 1. Vascular Constriction2. Platelet Plug Formation3. Coagulation

1. VasoconstrictionAs soon as the vessel is injured:Smooth muscle in the vessel walls constrictSlows the flow of blood through the openingTemporary lasts long enough for the platelets to secrete serotonin prolongs the vascular constrictions until step 2 starts

2. Platelet Plug FormationBreak in the vessel leaves underlying tissue exposed and attracts the plateletsGather in the injured area and create a platelet plug

http://www.bing.com/videos/search?q=how+blood+clots&view=detail&mid=BB4338AF0FA5F3276DCDBB4338AF0FA5F3276DCD&first=0

3. CoagulationFormation of a blood clotProcoagulants: factors in blood that promote clottingAnticoagulants: factors in blood that inhibit clottingNormally anticoagulants override procoagulants your body does NOT want your blood to clotCoagulation When a vessel is damaged, it starts a chemical reaction that promotes clot formation.Damaged vessels and the platelets release chemicals that activate the clotting factors in the bloodProthrombin (inactive) is activated to thrombinThrombin in the blood converts fibrinogen to fibrin. Fibrin makes a mesh net that sticks to the damaged tissue and traps blood cells and platelets to form a clot.

Clot Formation:

http://www.bing.com/videos/search?q=how+blood+clots&view=detail&mid=BB4338AF0FA5F3276DCDBB4338AF0FA5F3276DCD&first=0

Heart Attack:

http://www.youtube.com/watch?v=H_VsHmoRQKk