Homework Revision to include: Worksheet blood vessels if not done next lesson Jan ,3,4,5,a,b,8,9

Circulatory system of a mammal Aqa book p 184-5

Objectives How do large organisms move substances around their bodies? What are the features of the transport systems of large organisms? How is blood circulated in mammals?

How do large organisms move substances around their bodies? 1.When is a mass transport system necessary in an organism? Key words = surface area to volume ratio, active

Components of circulatory systems Multi-cellular animals overcome the limitations of diffusion by having a specialised circulatory system. This comprises: a heart vessels through which the fluid can flow. a fluid in which substances are transported (medium) The two types of circulatory system are open (e.g. molluscs, arthropods) and closed (e.g. vertebrates, a few invertebrates).

Closed circulatory systems In a closed circulatory system, blood is fully enclosed within blood vessels at all times. From the heart, blood is pumped through a series of progressively smaller vessels. In the smallest vessels, capillaries, substances diffuse in and out of the blood and into cells. Blood then returns to the heart via a series of progressively larger vessels. heart capillaries

What are the features of the transport systems of large organisms? 1.What is a medium? 2.What is a mass flow system? 3.Why is the system closed? Branching? 4.How is the pressure achieved in animals? Plants? 5.Why must there be a mechanism to ensure unidirectionality? 6.Why should there be a way to control the flow to suit the changing requirements of different parts of the organism?

Closed circulatory systems

The mammalian circulatory system

Left side of the heart receives Oxygenated blood and delivers it to the body tissues Deoxygenated blood and delivers it to the lungs Right side of the heart receives

How is blood circulated in mammals? What is double circulation? Why is it more effective than single circulation?

Copy diagram into notes. How many can you name? Next slide has all labels so leave blanks if not sure

Label your diagram add colour learn the names of the blood vessels !!

Circulation: true or false?