The Respiratory System

Question 1

State the chemical equation of cellular respiration.

Answer 1

6 O2 + C6H12O6 -> 6 CO2 + 6 H2O + ENERGY (ATP)

Question 2

Explain the details of gas exchange in more complex organisms. [3]

Answer 2

• Diffusion is inadequate due to their larger body size.
• Requires close association with the circulatory system.
• Body parts are differentiated for other uses.

Question 3

What is cellular respiration?

Answer 3

The metabolism of carbohydrates to transfer chemical energy to ATP.

Question 4

What are lungs, and how do they function in gas exchange? [3]

Answer 4

• Internal respiratory system connected to the air by means of internal passageways.
• All have a moist respiratory surface.
• Means of forcing air in contact with lung surface.

Question 5

Define partial pressure.

Answer 5

The pressure of each of the individual gases that make up the total pressure of a mixture of gases.

Question 6

Differentiate between internal and external respiration.

Answer 6

External respiration is the exchange of oxygen and carbon dioxide between air and blood, while internal respiration is the exchange of oxygen and carbon dioxide between blood and cells.

Question 7

How are gills used in complex organisms? [3]

Answer 7

• Ensure a large surface area for gas exchange.
• Gases diffuse in or out of circulatory vessels.
• Aquatic organisms keep gills moist.

Question 8

Describe the purpose of the nostrils in the upper respiratory tract. [3]

Answer 8

• Mucus (moistens and cleans air)
• Capillaries (warms air)
• Hair (traps particles)

Question 9

Define vital capacity.

Answer 9

Total volume of gas that can be moved in or out of lungs.

Question 10

Explain gas exchange in complex terrestrial organisms. [2]

Answer 10

• Keeping gas exchange surface moist is biggest challenge, which is usually solved with an internal respiratory surface.

Question 11

Describe the process of inhalation.

Answer 11

• Intercostal muscles between the ribs contract, moving the ribcage upwards and out
• Diaphragm muscle contracts.
• Processes cause a larger volume and decreased pressure, which creates a vacuum and therefore air rushes in.

Question 12

What is respiration?

Answer 12

It involves the diffusion of gases across a semi-permeable membrane.

Question 13

How is breathing controlled?

Answer 13

It is involuntary, controlled through our Autonomic Nervous System. Blood vessels in the brain detect the lowering pH of the blood when too much carbon dioxide is present, and signals the breathing center of the brain to increase the respiratory rate.

Question 14

Describe the purpose of the pharynx in the upper digestive tract.

Answer 14

• Connects the mouth and nasal cavity to the larynx and esophagus.

Question 15

Define tidal volume.

Answer 15

Volume of air inhaled and exhaled in normal breathing movement.

Question 16

Of the energy, or food we consume, how much gets released as heat, and how much is used for phosphorylation?

Answer 16

64% gets released as heat, and 36% is used for phosphorylation.

Question 17

Explain skin respiration in complex organisms. [3]

Answer 17

• Only in water or damp environments.
• Gases diffuse in or out of circulatory vessels.
• Entire body surface is used for gas exchange.

Question 18

Describe the process of the glottis in the upper digestive tract. [2]

Answer 18

• Opening of the trachea

- Protected by the epiglottis

Question 19

Name the four requirements of a mammalian respiratory system.

Answer 19

• Thin permeable membrane for diffusion of gases to occur
• Large surface area for gas exchange.
• Good supply of blood
• Breathing system for bringing air to the respiratory system.

Question 20

Define inspiratory reserve volume.

Answer 20

Additional volume of air that can be taken in.

Question 21

The lung is enveloped in a flexible membrane, ______.

Answer 21

Pleura

Question 22

Describe the process of exhalation.

Answer 22

• Intercostal mucles relax, moving the ribs downwards and in
• Diaphragm muscle relaxes
• Processes cause a smaller volume and increased pressure, which forces air out.

Question 23

Define residual volume.

Answer 23

Amount of air that remains after a full exhalation.

Question 24

State the difference between ventilation and gas exchange.

Answer 24

Ventilation is the movement of oxygen-rich air to the lungs and carbohydrate-rich air away from the lungs, and gas exchange is when oxygen diffuses into cells and carbon dioxide diffuses out.

Question 25

Explain the gas exchange in simple terrestrial organisms. [1]

Answer 25

They are usually found in damp environments to keep respiratory system moist.

Question 26

Explain the gas exchange in simple aquatic organisms. [2]

Answer 26

Simple diffusion of gas in and out is sufficient and no specialized respiratory system is required.

Question 27

Name the two basic requirements of a respiratory system.

Answer 27

1. Surface area of the respiratory system must be large enough to meet the needs of the organism.
2. Respiratory surface must be kept moist so that oxygen and carbon dioxide are dissolved.

Question 28

Define expiratory reserve volume.

Answer 28

Additional volume that can be forced out of lungs.