🫀 THREE MAIN COMPONENTS OF THE CIRCULATORY SYSTEM
(New Zealand Curriculum – Study Material) Name of the Student : SARAH
1️⃣ HEART – The Pump of the System
Function:
The heart is a muscular organ that works as a pump to circulate blood throughout the body. It keeps blood moving continuously, supplying oxygen and nutrients and removing waste.
Key Facts:
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Has four chambers – right atrium, right ventricle, left atrium, left ventricle
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Left side pumps oxygenated blood to the body
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Right side pumps deoxygenated blood to the lungs
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Beats about 70–75 times per minute on average
2️⃣ BLOOD VESSELS – The Pathways
Function:
Blood vessels are the network of tubes that carry blood to and from the heart and throughout the body.
Types of Blood Vessels:
| Vessel Type | Function |
|---|---|
| Arteries | Carry blood away from the heart (usually oxygen-rich) |
| Veins | Carry blood toward the heart (usually oxygen-poor) |
| Capillaries | Very thin vessels where exchange of gases, nutrients, and waste takes place between blood and cells |
3️⃣ BLOOD – The Transport Fluid
Function:
Blood is the fluid that carries essential substances throughout the body.
Components of Blood:
| Component | Function |
|---|---|
| Red Blood Cells (RBCs) | Carry oxygen using haemoglobin |
| White Blood Cells (WBCs) | Fight infections (part of immune system) |
| Platelets | Help in clotting to stop bleeding |
| Plasma | The liquid part that carries nutrients, hormones, and waste |
✅ Summary Table
| Component | Role |
|---|---|
| Heart | Pumps blood |
| Blood Vessels | Carry blood throughout the body |
| Blood | Transports oxygen, nutrients, waste, and fights infection |
