How Does Blood Travel Through the Body?
Are you looking for an easy way to teach your child about the human body? We’ve put together a set of free materials that parents and teachers can use right away. In this lesson, your child will dive into the fascinating world of how blood travels through the body.
We’ll explore components of blood and its journey through vessels. Explore science in a more engaging way with captivating 3D videos and interactive quizzes. Download our app to get started!
What You Will Learn from This Lesson
- Blood is made of plasma, red blood cells, white blood cells, and platelets.
- Blood flows from the heart, through arteries and capillaries, then back through veins.
Table of Contents
What Is Blood Made Of?
Blood travels inside blood vessels, delivering oxygen and nutrients to the entire body to keep us energized. Blood is composed of several key parts that work together to move and function:
- The yellowish liquid called plasma flows forward, carrying red blood cells and other cells, while delivering nutrients throughout the body.
- Red blood cells appear bright when they are carrying oxygen.
- White blood cells kill bacteria and viruses. The macrophage is a type of white blood cell.
- Platelets repair rips in the blood vessels to stop bleeding, which helps wounds heal.
How Does Blood Deliver and Exchange Materials?
Blood flows from larger arteries and branches into smaller and smaller vessels. This leads into the capillaries, which are the smallest blood vessels in our bodies. The capillaries act as exchange stations where vital materials are passed between blood and other body cells.
Inside the capillaries, the following exchanges occur:
- Red blood cells give oxygen to other cells and pick up carbon dioxide produced by those other cells. This exchange causes red blood cells to turn darker.
- Plasma delivers nutrients to the other cells in exchange for waste produced by those other cells.
After passing through the capillaries, the blood enters the veins and returns to the heart. Blood completes this entire journey in less than a minute.
Fun Fact
- Your blood zips through its entire body and heart journey in less than a minute.
- When you get a cut, platelets rush to the injury site and act like tiny plugs to stop the bleeding and help your wound heal.
- The smallest vessels the blood travels through are the capillaries.
Vocabulary
- Blood Vessels: The lines or tubes inside the body through which blood travels.
- Plasma: The yellowish liquid in blood that flows forward, carries other cells, and delivers nutrients throughout the body.
- Red Blood Cells: The components of blood that carry oxygen.
- White Blood Cells: Components of blood that kill bacteria and viruses.
- Platelets: Blood components that repair rips in blood vessels to stop bleeding, helping wounds heal.
- Capillaries: The smallest blood vessels in our bodies, where the red blood cells drop off oxygen and pick up carbon dioxide and waste.
- Arteries: The blood vessels that carry blood away from the heart to the rest of the body.
- Veins: The blood vessels that carry blood back to the heart.