Cardiovascular System Basics
Think of your cardiovascular system as your body's delivery service - it's made up of your heart, blood, and blood vessels working together. The main job is transporting oxygen and nutrients to every cell whilst removing nasty waste products that would otherwise poison you.
Your heart is basically a muscular pump split into two halves, and here's the clever bit - it works as a double-circulatory system. This means you've got two separate circuits running simultaneously, like having two delivery routes operating at once.
The right side of your heart deals with deoxygenated blood (blood that's used up its oxygen). It collects this tired blood from your body and pumps it to your lungs through pulmonary circulation. Meanwhile, the left side handles the fresh, oxygenated blood from your lungs and sends it around your body via systemic circulation.
Quick Tip: Remember "right to lungs, left to body" - this simple phrase will help you nail those exam questions about blood flow direction!
Blood Vessels and Key Terms
Your blood travels through three types of vessels, each perfectly designed for their job. Arteries have thick, muscular walls because they carry blood away from your heart under high pressure - think of them as motorways for blood flow.
Capillaries are the tiny delivery trucks with super-thin walls that allow gas and nutrients to transfer between blood and tissues. Veins bring blood back to your heart and have thin walls with special valves to prevent backflow.
Red blood cells are your oxygen carriers, packed with haemoglobin that grabs oxygen from your lungs. Without these little heroes, your muscles would fatigue instantly during any physical activity.
For your exams, you'll need to know these calculations: Heart rate (beats per minute), stroke volume (blood pumped per beat), and cardiac output (total blood pumped per minute). Master these terms and you're well on your way to exam success!