How Digestion and Blood Work Together

About this printable How Digestion and Blood Work Together science reading passage, NGSS-aligned (Grades 3-5)

This 250-word reading passage introduces fourth-grade students to the relationship between the digestive system and circulatory system, aligned with NGSS standard 4-LS1-1. Students discover how nutrients from food pass from the digestive system into the blood, and how the heart pumps nutrient-rich blood to every cell in the body. The passage uses simple, age-appropriate language to explain this key example of body systems working together. Audio-integrated features support diverse learners by providing text-to-speech functionality. The passage includes bolded vocabulary terms with immediate definitions, real-world examples, and an engaging fact about the digestive process. Supplementary activities include comprehension questions testing recall and application, writing prompts requiring explanation and connection-making, and graphic organizers that help students visualize the sequence of nutrient delivery and the structure-function relationships of body systems. A simplified differentiated version ensures accessibility for students reading below grade level. Spanish translations of both passages support English language learners. This comprehensive resource builds foundational understanding of how body systems interact, preparing students for hands-on investigations and deeper exploration of human body functions.

Written by Workybooks TeamPublished by Workybooks

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Sample passage and quiz from How Digestion and Blood Work Together

Illustration of digestive and circulatory systems delivering nutrients to body organs. — Digestive and circulatory systems working together to deliver energy to cells.

Your body has many different systems that work together to keep you alive and healthy. Two important systems are the digestive system (the parts of your body that break down food) and the circulatory system (the heart and blood vessels that move blood around your body). These two systems depend on each other to deliver the energy and materials your body needs.

When you eat food, your digestive system goes to work. Your stomach and intestines break down the food into tiny pieces called nutrients (substances from food that your body needs to grow and stay healthy). But these nutrients cannot help your body while they are still in your stomach or intestines. They need to travel to every part of your body—your brain, muscles, skin, and all your other organs.

This is where blood comes in. After nutrients are broken down in your digestive system, they pass through the walls of your intestines and enter your blood. Think of blood like a delivery truck that carries important packages to different addresses. Once the nutrients are in your blood, your heart pumps that nutrient-rich blood through blood vessels to every cell in your body. Without blood, the nutrients from your lunch would have nowhere to go. Without digestion, your blood would have nothing to deliver. These two systems must work together for your body to get the energy it needs.

Interesting Fact: Your small intestine is about 20 feet long, and it has tiny finger-like bumps called villi that help nutrients pass into your blood faster!