THREE MAIN COMPONENTS OF THE CIRCULATORY SYSTEM

---

🫀 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:

• Has four chambers – right atrium, right ventricle, left atrium, left ventricle

• Left side pumps oxygenated blood to the body

• Right side pumps deoxygenated blood to the lungs

• 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

---