Your heart helps you live, by moving about 5 liters (1.3 gallons) of blood through almost 100,000 kilometers (62,000 miles) of blood vessels every single minute! It has to do this all day, everyday. Learn about how the heart works, how blood flows through the heart and where the blood goes. This is an introduction to the heart and the circulatory system. It consists of nine videos and three quizzes, and covers: Meet the heart! Flow through the heart; Two circulations in the body; Lub dub; Layers of the heart; Thermoregulation in the circulatory system; Arteries vs veins: what's the difference?; Arteries, arterioles, venules, veins.

Roughly five liters of blood fill your arteries, veins, capillaries, and venules. It carries oxygen to help your cells carry out respiration in addition to a number of other substances like lipids and hormones throughout the body.  This course consists of 12 videos on the following topics: What's inside of blood? Red blood cells; Blood types; Blood cell lineages; Life and times of RBCs and platelets; Hemoglobin; Hemoglobin moves oxygen and carbon dioxide; Fetal hemogloin and hematocrit; Oxygen content; How do we make blood clots; Coagulation cascade; Bohr effect vs. Haldane effect.

Every thirty minutes, your kidneys filter the entire blood supply in your body. Imagine a dirty pool filled with algae. Placing a filter in this pool will cause the algae to be flushed out, and after a time you’ll have a clean, crisp blue pool to enjoy. This is what your kidneys do to your blood! This course contains 8 videos and a quiz at the end. The videos are on: Meet the kidneys! Kidney function and anatomy; Glomerular filtration in the nephron; Changing glomerular filtration rate; Countercurrent multiplication in the kidney; Urination; The kidney and nephron; Secondary active transport in the nephron.

Food and water play a powerful role in our everyday lives. If we were cars, food and water would be the gasoline. Eating keeps us moving, laughing, playing, and learning. The energy from food is carefully extracted through a process of ingestion, digestion, and absorption - this is the gastrointestinal system. This course consists of 15 videos on the following: Meet the gastrointestinal tract! Mouth; Teeth; Esophagus; Stomach; Small intestine 1: structure; Small intestine 2: Digestion; Small intestine 3: Absorption; Liver; Hepatic lobule; Biliary tree; Exocrine pancreas; Endocrine pancreas; Colon, rectum and anus; Control of the gastrointestinal tract.