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.

Figure out how to calculate an equivalent and how it relates to a mole. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Find out what a systolic and diastolic blood pressure mean. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Learn the categories of hypertension for systolic and diastolic blood pressures. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Learn the difference between the cold and the flu, and how we sometimes can get fooled by viruses! Rishi is a pediatric infectious disease physician and works at Khan Academy. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video.

Spin down your blood and find out what it's made up of. Rishi is a pediatric infectious disease physician and works at Khan Academy.

This video from NOAA details their greenhouse gas monitoring process. The resource, "What's in the Air: How NOAA Monitors Greenhouse Gases in our Atmosphere Part 2" included in "Lesson 1 Sources of Atmospheric Carbon" is a part of "Unit 02 Atmospheric Carbon" included in Energy & Sustainability ES - Course 4.

Learn how flu viruses get into and out of your cells using Hemagglutinin and Neuraminidase proteins on their surface. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Students use DNA profiling to determine who robbed a bank. After they learn how the FBI's Combined DNA Index System (CODIS) is used to match crime scene DNA with tissue sample DNA, students use CODIS principles and sample DNA fragments to determine which of three suspects matches evidence obtain at a crime location. They communicate their results as if they were biomedical engineers reporting to a police crime scene investigation.

This video is from the Khan Academy subject of Partner content on the topic of Crash Course and it covers Why Carbon is a Tramp.

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.

Meat is a complicated issue. But also a delicious one. Let's talk about it. The video "Why Meat is the Best Worst Thing in the World ??" is a resource included in the Environmental science topic made available from the Kurzgesagt open educational resource series.

The lower half of Mr. Andersen's head explains why cells are small. This video begins with a simple geometry problem and ends with a discussion of Allen's Rule and reasoning for the microscopic nature of cells.

This "The Winogradsky Column" learning object is the from the Sumanas resource series. Sumanas offers a robust selection of content and services that are directed at enhancing the learning experience.

In this interactive object, learners identify the parts of an animal cell and its organelles.

Learners view video clips demonstrating acid-fast staining procedures. Correctly stained slides are shown. The learning object includes two matching exercises.

In this animated and interactive object, learners examine how blood flows through the heart and lungs. A brief quiz completes the activity.

In this interactive learning activity, learners review the terms used to describe relative position of body parts in order to have a common set of words to describe their position.