HUMAN BREATHING SYSTEM

Question 1

Give two features of the alveoli and capillaries that allow for efficient gas exchange

Answer 1

Large surface area
Thin walled

Question 2

Name a disorder of the breathing system and say how it may be:
1. Caused.
2. Prevented.
3.Treated

Answer 2

Asthma
1. Allergic reaction e.g. pollen.
2. Avoid your triggers.
3. Inhaler.

Question 3

Which gas, dissolved in the blood, can trigger deeper or faster breathing?

Answer 3

Carbon dioxide.

Question 4

In the course of your practical studies you found that heart rate and breathing rate increase
with exercise.
Explain why this is the case.

Answer 4

More oxygen is required.

Question 5

When you investigated the effect of exercise on the human pulse rate or breathing rate what did you first establish?

Answer 5

Resting pulse rate.

Question 6

How did you measure pulse rate or breathing rate?

Answer 6

Feel your pulse, count the heart beats for a minute and repeat and find average.

Question 7

Outline the details of the process of inhalation.

Answer 7

The brain sends a message to muscles causing the intercostals and the diaphragm to contract.
The ribcage moves up and out and the diaphragm moves down. Volume of thoracic cavity increases. The pressure drops and air rushes in.

Question 8

Name a structure found in the cells in which carbon dioxide is produced.

Answer 8

Mitochondrion

Question 9

Give a feature of a capillary which allows the rapid uptake of carbon dioxide.

Answer 9

Wall one cell thick

Question 10

Carbon dioxide levels are usually higher in venous blood than arterial blood. Why is this the case?

Answer 10

Venous blood has collected CO2

Question 11

Name a blood vessel which is an exception to the situation outlined in (iii) above

Answer 11

Pulmonary Artery: Brings CO2-rich blood to the lungs.

Question 12

Briefly outline the role of carbon dioxide in the control of the human breathing rate.

Answer 12

More CO2 results in faster breathing.

Question 13

What is the pulse?

Answer 13

Alternate expansion and contraction of arteries.

Question 14

What makes the wrist a suitable part of the body to detect a pulse?

Answer 14

Arteries are close to the surface of the skin.

Question 15

What is the control for the breathing system experiment?

Answer 15

Rate of pulse measured at rest.

Question 16

What the purpose of the control?

Answer 16

To compare results.

Question 17

How can you measure recovery time?

Answer 17

Immediately after exercise count your pulse per minute and measure the length of time it took for you to get back to resting rate.

Question 18

Explain the term homeostasis

Answer 18

Maintenance of constant internal environment

Question 19

Why is homeostasis important in the human body?

Answer 19

It keeps temperature (or
pH) suitable for enzyme reactions.

Question 20

Blood vessel that capillary arises from.

Answer 20

Pulmonary artery (arteriole)

Question 21

Give three features of alveoli or their capillaries that allow for efficient gas exchange.

Answer 21

Large surface area
The wall is one cell thick
Moist surface

Question 22

Name the structures involved in gaseous exchange:

Answer 22

Alveoli

Question 23

Identify the gas that controls the rate of breathing:

Answer 23

CO2

Question 24

Identify the region of the human brain that detects the gas CO2:

Answer 24

Medulla oblongata

Question 25

How does the breathing system respond to a high level of CO2?

Answer 25

Increases rate of breathing.

Question 26

Name the process involved in the passage of gas between the alveoli and the blood.

Answer 26

Diffusion.