Hjärtat Publicerad 2013-10-22 21:54:16 i Hjärtat, Meet the heart!: Find out exactly where the heart rests in your body and what it does. Rishi is a pediatric infectious disease physician and works at Khan Academy. Layers of the Heart: Take a closer look at the heart, explore some of its interesting features and get to know the three layers that make up the heart. Rishi is a pediatric infectious disease physician and works at Khan Academy. Flow through the Heart: Learn how blood flows through the heart, and understand the difference between systemic and pulmonary blood flow. Rishi is a pediatric infectious disease physician and works at Khan Academy. Two Circulations in the Body: Learn the difference between the pulmonary and systemic circulatory systems in the body. Rishi is a pediatric infectious disease physician and works at Khan Academy. Lub Dub: Ever wonder why the heart sounds the way that it does? Opening and closing of heart valves makes the heart rhythm come alive with its lub dub beats... Rishi is a pediatric infectious disease physician and works at Khan Academy. Three types of muscle: Understanding the structure of a muscle cell. Heart Cells Up Close!: Get a close-up view of the cardiac cells and see what makes them different from the other (skeletal and smooth) muscle cells. Rishi is a pediatric infectious disease physician and works at Khan Academy. Myosin and actin: How myosin and actin interact to produce mechanical force. Tropomyosin and troponin and their role in regulating muscle contraction: Tropomyosin and troponin and their role in regulating muscle contraction. How calcium ion concentration dictates whether a muscle is contracting or not. Calcium puts myosin to work: See exactly how Calcium binds Troponin-C and allows Myosin to do some work. Sympathetic Nerves Affect Myosin Activity: Check out how the amount of Myosin that is tugging on your heart can change depending on your activity level! Rishi is a pediatric infectious disease physician and works at Khan Academy. Why Doesn't the Heart Rip?: Understand LaPlace's law to see the effect that pressure, radius, and wall thickness each have on the "wall stress" in the left ventricle. Rishi is a pediatric infectious disease physician and works at Khan Academy. Membrane Potentials - Part 1: Find out how a cell that is permeable to one ion can become charged (either positive or negative) if there is permeability and a concentration gradient. Rishi is a pediatric infectious disease physician and works at Khan Academy. Membrane Potentials - Part 2: Find out how a cell that is permeable to one ion can become charged (either positive or negative) if there is permeability and a concentration gradient. Rishi is a pediatric infectious disease physician and works at Khan Academy. Permeability and Membrane Potentials: Find out why a cell that is permeable to multiple ions has a membrane potential that is influenced by the ion with the highest permeability. Rishi is a pediatric infectious disease physician and works at Khan Academy. Action Potentials in Pacemaker Cells: Find out how the pacemaker cells use the movement of sodium, calcium, and potassium to get your heart beating! Rishi is a pediatric infectious disease physician and works at Khan Academy. Action Potentials in Cardiac Myocytes: See how muscle cells in the heart contract by allowing Calcium to flow inside and bringing along some positive charge with it! Rishi is a pediatric infectious disease physician and works at Khan Academy. Reseting Cardiac Concentration Gradients: Watch as the heart cells use energy to reset the concentration gradients for all of the ions after the action potential has gone through. Rishi is a pediatric infectious disease physician and works at Khan Academy. Electrical System of the Heart: See where the pacemaker cells start the electrical wave of depolarization, and how it gets all the way to the ventricles of the heart. Rishi is a pediatric infectious disease physician and works at Khan Academy. Depolarization Waves Flowing through the Heart: Get a clearer idea of what a "Depolarization Wave" means and how it goes from cell to cell through the entire heart! Rishi is a pediatric infectious disease physician and works at Khan Academy. A Race to Keep Pace!: Find out how the various pacemaker cells in the heart actually race against the clock to try to keep pace for the heart, and how the heart has not one but two back up systems! Rishi is a pediatric infectious disease physician and works at Khan Academy. Thinking about Heartbeats: Find out what happens when things move very slowly through the AV Node! Rishi is a pediatric infectious disease physician and works at Khan Academy. New Perspective on the Heart: Take a look at the heart in cross section, looking down at it from the top! Rishi is a pediatric infectious disease physician and works at Khan Academy. Pressure in the Left Heart - Part 1: Watch the pressure in the left heart go up and down with every heart beat! Rishi is a pediatric infectious disease physician and works at Khan Academy. Pressure in the Left Heart - Part 2: Watch the pressure in the left heart go up and down with every heart beat! Rishi is a pediatric infectious disease physician and works at Khan Academy. Pressure in the Left Heart - Part 3: Watch the pressure in the left heart go up and down with every heart beat! Rishi is a pediatric infectious disease physician and works at Khan Academy. Left Ventricular Pressure vs. Time: Ever wonder exactly how the left ventricle's pressure changes over time? Find out in this color-coded video! Rishi is a pediatric infectious disease physician and works at Khan Academy. Left Ventricular Volume vs. Time: Left ventricular volume changes over time in a way that makes a curious looking graph. Learn more in this video! Rishi is a pediatric infectious disease physician and works at Khan Academy. Drawing a Pressure-Volume Loop: Use the left ventricular pressure and volume information to put together a cool new graph. Rishi is a pediatric infectious disease physician and works at Khan Academy. Understanding the Pressure-Volume Loop: Figure out how all of those physiology terms: end-systolic, end-diastolic, pulse pressure, stroke volume, and ejection fraction, can be easily figured out using the pressure-volume loop. Rishi is a pediatric infectious disease physician and works at Khan Academy. End Diastolic Pressure-Volume Relationship (EDPVR): Find out what happens when the left ventricle is not allowed to contract, and instead you simply add and take away blood from it. Rishi is a pediatric infectious disease physician and works at Khan Academy. End Systolic Pressure-Volume Relationship (ESPVR): Find out what happens when the left ventricle is not allowed to relax, and instead you simply add and take away blood from it. Rishi is a pediatric infectious disease physician and works at Khan Academy. Reimagine the Pressure Volume Relationship: Understand what is happening at the cellular level to cause two identical left ventricular volumes to have such different pressures! Rishi is a pediatric infectious disease physician and works at Khan Academy. What is Preload?: Some say Preload = End-Diastolic Pressure, others say Preload = End-Diastolic Volume, so which one is it? Watch and find out! Rishi is a pediatric infectious disease physician and works at Khan Academy. Kommentarer (0)
