4. What are veins and arteries? What do they do?

Veins and arteries are like the highways of the human body, each serving distinct purposes in transporting blood. Arteries carry oxygen-rich blood away from the heart to nourish organs and tissues, while veins bring deoxygenated blood back to the heart for reoxygenation. It's fascinating how these vessels work together to keep our body energized and functioning efficiently! In real-world terms, when you exercise, your demand for oxygen increases, prompting your heart to pump more blood through arteries to meet this need. On the flip side, a sedentary lifestyle can lead to weakened veins and potential problems like varicose veins. Keeping active is key to ensuring these critical blood vessels perform their best!