Circulatory System and Pathway of Blood Through the Heart
Introduction to the Circulatory System
In this video, we will learn about the basics of the circulatory system and how blood travels through the heart. We will also discuss the components of blood and their functions.
Blood
- Human blood is red and always red although the shade of red can vary based on how much oxygen is in the blood.
- Blood is made up of different components including plasma, which is a liquid portion containing water, proteins, salts, and lipids. Cellular components include red blood cells that transport gases, white blood cells that fight infections, and platelets that help with clotting.
Heart Anatomy
- The human heart has two distinct partitions - a deoxygenated partition and an oxygenated partition. Arteries generally carry oxygen-rich blood away from the heart while veins typically carry oxygen-poor blood to the heart.
- Capillaries are small vessels where oxygen is delivered to organs and tissues while carbon dioxide is picked up to travel back to lungs. The right side of the heart pumps deoxygenated blood while left side pumps oxygenated blood.
Tracing Pathway of Blood Through Heart
- Deoxygenated blood from a human toe enters inferior vena cava before entering right atrium. Right atrium contracts pushing it through tricuspid valve into right ventricle. Right ventricle contracts pumping it through pulmonary valve to pulmonary artery leading to lungs for gas exchange.
- Oxygenated blood returns from lungs via pulmonary vein entering left atrium before passing through mitral valve into left ventricle. Left ventricle contracts pumping it through aortic valve into aorta leading to the rest of the body.
The Pathway of Blood
This section explains the pathway of blood through the heart and body.
Oxygenated Blood Pathway
- Oxygenated blood travels through a pulmonary vein to the left atrium.
- The left atrium contracts and the blood travels through the mitral valve into the left ventricle.
- The left ventricle contracts and pumps the blood through the aortic valve and out a major artery known as the aorta.
Heart's Blood Supply
- The heart needs its own blood supply to deliver oxygen and glucose.
- The heart can receive this blood supply through coronary arteries.
- Coronary arteries branch off from the aorta and eventually deliver blood into capillaries.
Deoxygenated Blood Pathway
- Coronary veins take deoxygenated blood to the right atrium where it will eventually travel back to become oxygenated.
- To quiz yourself, trace this pathway: Right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary artery, lungs, back through pulmonary vein, left atrium, mitral valve (bicuspid valve), left ventricle, aortic valve, aorta.
Significance of Cardiac Cycle
This section discusses how every beat of your heart is coordinated and directed where it should go.
Coordinated Sequence of Heart Contractions
- A human heart beats over 100,000 times per day so it’s significant that every beat is coordinated and blood is directed where it should go.
- The complexity of cardiac cycle isn't something this short video can go into; hopefully in another video soon.
Heart Conditions
This section discusses heart conditions that change the pathway flow of blood.
Atrial Septal Defect
- An atrial septal defect is an example of a heart condition that changes the pathway flow of blood.
- The septum is the muscular wall that separates the right and left side of the heart.
- A septal defect could mean an opening and oxygen-rich blood could mix with oxygen-poor blood.
- Depending on the size, this can cause future problems such as an abnormal heartbeat, stroke, or potentially heart failure in severe cases.
Treatment for Cardiovascular Conditions
- Some medications may help symptoms or surgery can be an option.
- There continues to be more advancements for treating cardiovascular conditions.
Conclusion
This section concludes the video.
Final Thoughts
- The significance of pathways, how they interact, coordination of contraction, and many more elements are part of every beat of your heart.
- If you have interest in cardiology, take a look at suggested further reading links in video details.