The Circulatory System
Learning goals
By the end of this lesson, you should be able to:
1. Explain the main jobs of the circulatory system.
2. Trace the path of blood through the heart, lungs, and body.
3. Describe the structure of the heart and what each chamber/valve does.
4. Compare arteries, veins, and capillaries.
5. Identify common health issues and basic ways to keep the system healthy.
What it does
The circulatory (cardiovascular) system is the body’s transport network. It:
• Delivers oxygen and nutrients to cells
• Removes carbon dioxide and other wastes
• Transports hormones and immune cells
• Helps regulate temperature and pH
• Protects you with clotting (prevents excessive bleeding)
Main parts
• Heart = pump
• Blood vessels = pipes (arteries, veins, capillaries)
• Blood = fluid that carries materials
Blood basics
Blood has 4 major components:
1. Plasma: liquid part; carries nutrients, hormones, wastes
2. Red blood cells (RBCs): carry oxygen using hemoglobin
