Study Notes
The circulatory system is the body's transportation network, delivering oxygen and nutrients to cells and removing waste products. It includes the heart, blood vessels, and blood components, working together to maintain health and homeostasis.
- Heart — a muscular organ that pumps blood throughout the body. Example: The heart has four chambers and valves to ensure one-way blood flow.
- Arteries — blood vessels that carry oxygen-rich blood away from the heart. Example: The aorta is the largest artery in the body.
- Veins — blood vessels that return deoxygenated blood to the heart. Example: The vena cava is the largest vein, bringing blood back to the heart.
- Capillaries — tiny blood vessels where exchange of substances occurs. Example: Capillaries have thin walls to facilitate the exchange of oxygen and nutrients.
- Red blood cells — cells that transport oxygen using haemoglobin. Example: Haemoglobin binds oxygen in the lungs and releases it in tissues.
- White blood cells — cells that defend the body against infection. Example: Phagocytes engulf and destroy bacteria.
- Platelets — cell fragments involved in blood clotting. Example: Platelets form a plug to stop bleeding at injury sites.
Exam Tips
Key Definitions to Remember
- Circulatory system: The network responsible for transporting blood throughout the body.
- Arteries: Vessels carrying blood away from the heart.
- Veins: Vessels carrying blood to the heart.
- Capillaries: Small vessels where exchange of gases and nutrients occurs.
Common Confusions
- Confusing arteries with veins in terms of the direction of blood flow.
- Mixing up oxygenated and deoxygenated blood.
Typical Exam Questions
- What is the function of the heart? The heart pumps blood throughout the body.
- How do arteries differ from veins? Arteries carry blood away from the heart; veins carry it to the heart.
- What role do capillaries play in the circulatory system? They facilitate the exchange of oxygen, nutrients, and waste.
What Examiners Usually Test
- Understanding of the double circulation system in mammals.
- The structure and function of the heart and its components.
- The role of blood components in transport and defense.