--- title: "The circulatory system" description: "Identify and name the main parts of the human circulatory system and describe the functions of the heart, blood vessels, and blood" canonical: https://lightmysky.com/learn/science/the-circulatory-system-mt_BX4D8cCFtQ source: https://lightmysky.com/learn/science/the-circulatory-system-mt_BX4D8cCFtQ.md retrieved: 2026-11-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # The circulatory system Identify and name the main parts of the human circulatory system and describe the functions of the heart, blood vessels, and blood Subject: Science · Area: Organisms & Life Processes · Ages 10 to 11 Page: https://lightmysky.com/learn/science/the-circulatory-system-mt_BX4D8cCFtQ ## Ready when they can - Name the main components: heart, arteries, veins, capillaries, blood - Describe the heart as a pump that pushes blood around the body in a continuous loop - Explain that blood carries oxygen and nutrients to cells and removes waste products like carbon dioxide ## Lesson: How your blood gets around You have learned the names artery, vein, and capillary. These are the three main types of blood vessel, the tubes blood travels through. The circulatory system has three main parts: the heart, blood vessels, and blood. The heart is a muscular pump. It squeezes to push blood through vessels. *(drawing: Follow the boxes in order. This body route leaves the heart through arteries and returns through veins. It repeats.)* Arteries carry blood away from the heart. Veins carry blood toward it. In the body's tiny capillaries, oxygen and nutrients pass from blood through thin walls to nearby cells. Carbon dioxide, a waste gas made by cells, passes into the blood. Blood carries supplies to cells and takes waste away. **Example.** When Maya runs, her working muscles need more oxygen. Her heart beats faster and sends more blood to them. At body capillaries, blood delivers oxygen and nutrients and collects carbon dioxide from the cells. Veins return this blood to the heart. The heart then pumps it to the lungs, where carbon dioxide leaves the blood to be breathed out. Blood makes two linked loops. One goes from the heart to the lungs and back. In the lungs, blood loses carbon dioxide and gains oxygen. The other goes from the heart to the rest of the body and back. Each loop returns blood to the heart, ready to be pumped onward. **Recap.** The heart pumps blood through lung and body loops. Arteries carry it away, veins bring it back, and capillaries let supplies and waste pass between blood and cells. *Original circulatory-system lesson, questions and flashcards written for this dataset.* ## Practice 8 questions on this page, each with its working shown. ## Needs first - [Organ Systems Vocabulary](https://lightmysky.com/learn/science/organ-systems-vocabulary-mt_K8DJzqbksM) - [The Digestive System](https://lightmysky.com/learn/science/the-digestive-system-mt_Ruk2-lyGPZ) ## Optional connections - [Heart & Blood Circulation](https://lightmysky.com/learn/science/heart-and-blood-circulation-mt_g_M4Vh_pK7) - [Skeletons & Muscles](https://lightmysky.com/learn/science/skeletons-and-muscles-mt_g4YSiOCS8g) ## Opens up - [Diet, Exercise & Lifestyle](https://lightmysky.com/learn/science/diet-exercise-and-lifestyle-mt_2x-EwdBsgl) - [Heart structure & double circulation](https://lightmysky.com/learn/science/heart-structure-and-double-circulation-mt_TR2oTy9c2M) - [Nutrient Transport in Animals](https://lightmysky.com/learn/science/nutrient-transport-in-animals-mt_YSyjTZfjvv)