Meet the heart!Flow through the heartTwo circulations in the bodyThe heart is a double pumpLub dubLayers of the heartThermoregulation in the circulatory systemArteries vs. veins - what's the difference?Arteries, arterioles, venules, and veinsCirculatory system and the heart
What is blood pressure?Learn how a stethoscope can help determine blood pressureResistance in a tubeAdding up resistance in series and in parallelAdding up resistance problemFlow and perfusionPutting it all together: Pressure, flow, and resistanceBlood pressure changes over time
Regulation of blood pressure with baroreceptorsParts of a nephronGeneral overview of the RAAS system: Cells and hormonesRenin production in the kidneysActivating angiotensin 2Angiotensin 2 raises blood pressureAldosterone raises blood pressure and lowers potassiumAldosterone removes acid from the bloodADH secretionADH effects on blood pressureAldosterone and ADH
Meet the placenta!Umbilical vessels and the ductus venosusFlow through the heartHypoxic pulmonary vasoconstrictionForamen ovale and ductus arteriosusFetal hemoglobin and hematocritDouble Bohr effectFetal circulation right before birthBaby circulation right after birthFetal structures in an adult
Three types of muscleHeart cells up close!Myosin and actinHow tropomyosin and troponin regulate muscle contractionCalcium puts myosin to workSympathetic nerves affect myosin activityWhy doesn't the heart rip?
Membrane potentials - part 1Membrane potentials - part 2Permeability and membrane potentialsAction potentials in pacemaker cellsAction potentials in cardiac myocytesResetting cardiac concentration gradientsElectrical system of the heartDepolarization waves flowing through the heartA race to keep pace!Thinking about heartbeatsNew perspective on the heart
Changing the AV node delay - chronotropic effectChanging the heart rate - chronotropic effectIncreasing ventricular contractility - inotropic effectAutonomic nervous system effects on the heartGetting a new heart
Why doesn't the heart rip?What is preload?Preload and pressurePreload stretches out the heart cellsFrank-Starling mechanismSarcomere length-tension relationshipActive contraction vs. passive recoilWhat is afterload?Increasing the heart's force of contraction
Pressure in the left heart - part 1Pressure in the left heart - part 2Pressure in the left heart - part 3Left ventricular pressure vs. timeLeft ventricular volume vs. timeDrawing a pressure-volume loopUnderstanding the pressure-volume loopEnd diastolic pressure-volume relationship (EDPVR)End systolic pressure-volume relationship (ESPVR)Reimagine the pressure volume relationshipWhat is preload?Why doesn't the heart rip?
What is preload?What is afterload?Increasing the heart's force of contractionReimagine the pressure volume relationshipWhat is contractility?Getting Ea (arterial elastance) from the PV loopArterial elastance (Ea) and afterloadArterial elastance (Ea) and preloadStroke work in PV loops and boxesContractility, Ea, and preload effects on PV boxesPressure-Volume Boxes
About this unit
Your heart sits in the middle of your chest and pumps blood from about 4 weeks after conception until the day that you die. This little pump is the size of your clenched fist and it never stops. Watch these videos to learn more about how the heart works, blood flow in arteries and veins, blood pressure, and lymphatics.