F2 IS WS10 Answers

1st Term WS 10 Submission date：_____________ Name：______________________ Class & no.：2 _________(     )

7.6       Breathing and breathing system

             in humans

A.     The importance of breathing

B.      Our breathing system

i      Matching:

Breathing	•	•Drawing of air in and out of the lungs
Gaseous exchange	•	•Exchange of oxygen and carbon dioxide between the air and the blood
		inside lungs
Respiration	•	•Complicated chemical process which release energy from food

i      Fill in the blanks:

1       Our living cells need continuous supply of oxygen for use in respiration for releasing energy.

2       Breathing is a process by which air is repeatedly drawn into and out of the lungs.

3       Through gaseous exchange in our lungs, we obtain oxygen from the environment and        release carbon dioxide to the environment. Oxygen in the air enters the blood while carbon dioxide leaves the blood and goes into the air.

4       In the human body, there is a well-developed breathing system that facilitates gaseous exchange. Lung is the part of this system in which gaseous exchange occurs.

5       Sequence (次序) of structures through which air enters the breathing system:

         Air     à Nose   à Trachea à Bronchus à small tubes à Air sacs

                       or mouth

6        Label the following diagrams:

           Nose

           Trachea

           Lung

           Bronchus

           Ribs

           Intercostal muscle

           Diaphragm

          

           Air sac

7       In the air sacs, oxygen enters the blood (air / blood) from the air

while carbon dioxide leaves the blood and goes into the air.

8       The following table shows the difference between the blood entering and leaving the air sacs:

	Blood entering air sacs	Blood leaving the air sacs
Come from	Living cells / air sacs	Air sacs
Go to	Air sacs	Living cells
Oxygen content	Higher / Lower	Higher
Carbon dioxide content	Higher	Lower