Learn: The Circulatory System

Welcome!Great to have you here! You've already learned about the digestive system and enzymes, which help break down food into nutrients. Today, we'll build on that by exploring how these nutrients are transported around the body through the circulatory system.

What is the Circulatory System?The circulatory system is a network of the heart, blood vessels, and blood that transports oxygen, nutrients, and waste products around the body. It's essential for providing cells with what they need to function and removing waste materials.

The HeartThe heart is a muscular organ that pumps blood throughout the body. It has four chambers: two upper chambers called atria and two lower chambers called ventricles. The heart is responsible for pumping oxygen-rich blood to the body and oxygen-poor blood to the lungs.

Blood VesselsBlood vessels are the tubes that carry blood throughout the body. There are three main types: arteries, which carry blood away from the heart; veins, which carry blood back to the heart; and capillaries, which are tiny vessels where substances are exchanged between blood and tissues.

Double CirculationHumans have a double circulatory system. This means blood passes through the heart twice for every full circuit of the body. One loop sends blood to the lungs (pulmonary circulation), and the other sends blood to the rest of the body (systemic circulation).

Key Components of BloodBlood is made up of red blood cells, white blood cells, platelets, and plasma. Red blood cells transport oxygen, white blood cells fight infections, platelets help clot blood, and plasma carries dissolved substances like nutrients and waste.

How Blood Moves Through the HeartBlood enters the heart through the atria. It is then pumped from the atria to the ventricles. The ventricles contract to send blood to the lungs or the rest of the body depending on the circuit.

Review Time!Fantastic work! You've learned about the circulatory system, heart, blood vessels, and double circulation. Now let's test your understanding with a few questions.