Risk Factors for Stroke:
In this Khan Academy video you will learn some of the modifiable and non-modifiable risk factors that can lead to a stroke.
What is a Stroke?:
Learn the conditions present in your brain that cause a stroke.
The Circulatory System and the Heart:
This Khan Academy video explains the major vessels involved in the flow of blood and follows the steps that blood takes as it travels through the heart.
Conducting System of the Heart:
This tutorial will help you to understand how all of the components of the heart are able to work together without direct control from the central nervous system. This video shows that for proper function of the heartbeat, it is necessary that all of the muscle fibers in a region contract in unison.
Baroreceptor Reflex Control of Blood Pressure:
Blood pressure is determined by the force of the blood acting on the walls of the blood vessels. Two factors determine the size of this force. One is the volume of blood being pumped through the vessel. The other is the size of the vessels. Changes in blood pressure can be caused by either a change in the amount of blood being pumped or by a change in the size of the blood vessels. Feedback mechanisms, described in this animation, will alter heart rate and blood vessel dilation to maintain blood pressure at appropriate levels.
Chemoreceptor Reflex Control of Blood Pressure:
This tutorial will help students to understand how concentrations of gases in the blood change during breathing. This animation shows high carbon dioxide concentrations and low oxygen concentrations indicating that gas exchage is occurring at a slower than ideal rate. Because of this, heart rate increases or decreases to compensate the exchange of gas.
How the Heart Actually Pumps Blood:
This TED ED original lesson takes a closer look at how the heart pumps blood. For most of history, scientists weren't quite sure why our hearts were beating or even what purpose they served. Eventually, we realized that these thumping organs serve the vital task of pumping clean blood throughout the body. But how? Edmond Hui investigates how it all works by taking a closer look at the heart's highly efficient ventricle system.
Zebrafish Heart Regeneration:
This video presentation will help to understand the regeneration process in a zebrafish. When the zebrafish heart is damaged, the wound site is rapidly sealed with a fibrin clot that stems bleeding within seconds. Following clot formation, the tissue that surrounds the heart muscle, the epicardium, gradually covers the fibrin clot via migration and cell division. Over the next few months, new cardiac muscle is produced and replaces the clot.