In this chapter, you will learn to: / outline the functions of the circulatory system / describe the roles of plasma and the three types of blood cells
/ identify and explain the roles of the elements of the circulatory system
/ describe how blood flows around the body / measure your pulse.
The circulatory system The circulatory system has three main functions: 1. To transport the substances needed for energy and growth to the body’s cells and remove waste
2. To protect the body against disease 3. To help regulate body temperature
The circulatory system is made up of: • blood
• blood vessels White blood cells Red blood cells Plasma (55%) Platelets
White blood cells and
platelets (1%)
Red blood cells (44%)
)Fig. 7.1 The composition of blood
? TEST TUBE
1. The human body must stay the same temperature at all times (around 37 °C). The movement of heat around the circulatory system helps with this. Research why you can see the veins in your hands more clearly when the weather is hot.