Arteries vs. veins-what's the difference? | Circulatory system physiology | NCLEX-RN | Khan Academy

TL;DR

Arteries carry oxygenated blood away from the heart, while veins carry deoxygenated blood towards the heart.

Transcript

• [Instructor] Let's talk a little bit about arteries and veins and the roles they play in the circulatory system. So I want you to pause this video and first think to yourself, Do you have a sense of what arteries and veins are? Well one idea behind arteries and veins are that well, in most of these drawings, arteries are drawn in red, and I even ... Read More

Key Insights

• 🥰 Arteries carry oxygenated blood away from the heart, while veins carry deoxygenated blood towards the heart.
• 🩵 The misconception that deoxygenated blood in veins appears blue is due to the way light interacts with the vessels.
• 😘 Arteries have high pressure, while veins have low pressure.
• 🥰 Veins have valves to facilitate the one-way flow of blood towards the heart.
• 🔈 Arteries have low volume, while veins have high volume.
• 🥰 Exceptions like the pulmonary artery carry deoxygenated blood away from the heart.
• ❓ The circulatory system consists of both pulmonary and systemic circulation.

Questions & Answers

Q: Why are arteries commonly depicted as carrying oxygenated blood in red?

Arteries are often shown as red because they typically carry oxygenated blood. However, this is not always the case, as there are exceptions like the pulmonary artery which carries deoxygenated blood to the lungs.

Q: What causes veins to appear blue?

Veins appear blue due to an optical illusion created by the way light passes through the skin and reflects off the veins. The actual color of the blood in the veins is a deeper red, not blue.

Q: Why do arteries have high pressure while veins have low pressure?

Arteries have high pressure because they are directly pumped by the heart, while veins have low pressure as the blood is returning to the heart in a slower, less forceful manner.

Q: Why do veins have valves?

Veins have valves to prevent the backward flow of blood. Since blood in veins is not being directly pumped by the heart, the valves ensure that the blood flows in one direction, towards the heart.

Summary & Key Takeaways

• Arteries and veins can be differentiated by the direction in which they carry blood - arteries carry blood away from the heart, while veins carry blood towards the heart.

• It is a misconception that veins carry blue, deoxygenated blood. Veins appear blue due to the way light reflects off the vessels.

• Arteries are under high pressure and have low volume, while veins have low pressure and high volume.