8.1 The Circulatory System

Fig. 1 represents a capillary as it passes through the tissues of the body along with the surrounding tissue fluid.

Fig. 1

Give three differences between the composition of the blood at the arteriole end of the capillary and the venule end.

Use Fig. 1 to explain the formation of tissue fluid and its return to the capillary.

Protein deficiency in an individual's diet can influence the return of tissue fluid to the capillaries.

Suggest and explain one tissue fluid-related symptom of dietary protein deficiency.

The main component of both blood and tissue fluid is water.

Explain how one property of water makes it an ideal transport medium for organisms with a transport system.

Based on your knowledge of diffusion, explain why multicellular organisms need a specialised transport system.

Fig. 1 shows two organs of the mammalian circulatory system.

Fig. 1

Identify the organs labelled X and Y. 

[1]

Explain the evidence shown in Fig. 1 that determined your answer to part (i).

[2]

Fig. 2 shows a biological drawing of organ X

Fig. 2

Describe the errors contained within this drawing.

The heart, contains two blood vessels that transport blood via the lungs. 

Give the name of these two blood vessels. 

[1]

Explain the movement of blood between the heart and the lungs. Do not include details of the cardiac cycle as part of your answer.

[4]

Fig.1 shows an image of a micrograph of a cross section through a mammalian blood vessel.

Fig. 1

Identify the type of blood vessel shown in Fig.1.

Explain how the blood vessel shown in Fig.1 is adapted to carry out its function.

Fig. 2 shows pressure changes in the blood vessels as the blood passes through different sections of the mammalian circulatory system.

Fig. 2

Explain the need for a separate systemic and pulmonary circulation in mammals. 

Explain the blood pressure in the following sections of Fig. 2

[3]

[1]

[1]