Khan Academy: Preload and Afterload: Sarcomere Length Tension Relationship

A video exploring the definition of preload and afterload as it relates to the study of the heart. Understand that preload is the stretch of the heart at the beginning of systole while afterload is the squeeze at the end of systole. [10:27]

Carefully follow five different preload scenarios to see how each one will have a different effect on how actin and myosin line up. Rishi is a pediatric infectious disease physician and works at Khan Academy. [14:18]

Find out why stretching a heart cell in diastole affects how forcefully it contracts in systole. Rishi is a pediatric infectious disease physician and works at Khan Academy. [12:41]

Go through the similarities and differences between the sarcomere and a slingshot! This video explores a contraction in terms of what happens to the interaction between actin and myosin and the length of the sarcomere. Then the video...

Find out exactly how stretch increases force of contraction in end-diastole, whereas more calcium increased force of contraction in end-systole in this video lecture. [14:29]

Khan Academy presents the rules and processes of naming alkanes and cycloalkanes. [12:34]

How can oxidizing and reducing agents be identified? Sal Khan will explain. [8:25]

An introduction to oxidation states, oxidation, and reduction. Find some tips for remembering oxidation and reduction. [10:09]

Identify the anode and cathode in a galvanic cell and calculate the voltage using standard electrode potentials. [4:28]

An introduction to mechanisms and the rate determining step. Review the example of finding rate law of multistep reaction with an initial slow step. [8:36]