Transport in Animals: Circulatory Systems and Blood

Syllabus tag: KCSE | Biology | Form 2 | Topic 2 Transport in Animals

Lesson objectives

By the end of this topic, you should be able to:

• Distinguish between open and closed circulatory systems.
• Describe the structure and functions of arteries, veins and capillaries.
• Describe the composition and functions of blood.
• Explain blood groups, clotting and immunity.

Summary

Animals transport materials in blood. Simple animals have an open system in which blood bathes the organs directly; vertebrates have a closed system in which blood stays within vessels. Mammals have a double circulation, passing through the heart twice per circuit. Blood is plasma carrying red cells, white cells and platelets, each with a distinct job.