Need for transport: Circulatory system. Homework

Nat 5 Lungs Homework

1. (a) Copy the table below and decide if each of the followingstatements about the breathing system is True or False, and tick () the appropriate box.

If the statement is false, write the correct word in the Correction box to replace the word underlined in the statement.

(b)The following graphs show changes in lung pressure and volume during breathing in and breathing out.

Statement True False Correction

The trachea divides into two bronchioles.

Air sacs are moist toallow oxygen to dissolve.

Large numbers ofcapillaries surround theair sacs.

Need for transport: Circulatory system. Homework

(i) From Graph 2 calculate the volume of air breathed out in one breath.

(ii) State the relationship between lung pressure and the volume of the air in the lungs during breathing in.

(iii) What evidence from Graph 2 supports the statement that the lungs are never completely empty of air?

2. (a) The diagram below shows an air sac and a capillary in the lungs.

(i)Name the process by which oxygen moves from the air sac into the capillary.

(ii)Why is oxygen required by an organism?

(iii)Copy and complete the following sentence using the words ‘high’ or ‘low’.

Oxygen is moving from a ____________ concentration in the air sac to a

______________ concentration in the capillary.

(iv) Name a substance which moves from the capillary into the air sac.

(b)Give two features of the air sacs which make them efficient gas exchange surfaces.

Need for transport: Circulatory system. Homework

Questions 3 and 4 refer to the diagram which shows the structure of the lungs.

3. Which label identifies the bronchioles?

4. The function of part A is to

A prevent the lungs from collapsing

B keep the trachea open at all times

C prevent food entering the windpipe

D trap dirt and bacteria

5. (a) The diagram below shows a capillary network similar to that found surrounding air sacs in the lungs.

State two features of the capillary network in the lungs that allow efficient gas exchange to take place.Explain how each feature improves gas exchange.

Need for transport: Circulatory system. Homework

(b) The diagram below shows gas exchange taking place in the tissues.

Name the process by which gases pass between capillaries and body cells.

6. The oxygen concentration of the air decreases as the height above sea level increases.

The table below shows the red blood cell count of a mountaineer taken at different heights above sea level.

(a) On a grid, plot a line graph to show red blood cell count against height above sea level.

(b) (i) From the table, describe the relationship between the height above sea level and the red blood cell count.

(ii) Explain the importance of this change in the red blood cell count.

Height above sea level(metres)

Red blood cell count(millions/mm3 of blood)

200 50

1000 56

2200 65

3600 76

4800 85

Need for transport: Circulatory system. Homework

Need for transport: Circulatory system. Homework

7.(a) (i) Describe two features of the lungs which make them efficient gas exchange surfaces.

(ii) Name the structures in the lungs through which oxygen diffuses from the air into the blood capillaries.

(b) The table below shows the rates of oxygen intake and energy release during various activities.

Describe the relationship between oxygen intake and energy release.

8. Describe the functions of machrophages and lymphocytes in defence.

A labelled diagram may be included if appropriate.

Activity Rate of oxygen intake(cm3/second)

Rate of energy release(joules/second)

Resting 35 70

Playing golf 20 400

Playing tennis 25 500

Playing football 30 600