Biology: Respiratory System

Question 1

What is the air pathway?

Answer 1

nose
nasal cavity 
pharynx
larynx 
trachea 
2 bronchi 
bronchioles 
alveoli

Question 2

What happens during inspiration?

Answer 2

the diaphragm and intercostal muscles contract
diaphragm moves down
thoracic volume increases and pressure decreases
so air is drawn into the lungs

Question 3

What happens during expiration?

Answer 3

the muscles relax
diaphragm moves upwards
thoracic volume decrease and pressure increase and the lungs deflate

Question 4

Define external respiration:

Answer 4

the exchange of oxygen and carbon dioxide in the lungs between the alveoli and the pulmonary capillaries

Question 5

What aids the diffusion of gases in the alveoli?

Answer 5

large surface area, thin walls, moist lining and good blood supply

Question 6

What carries oxygen to respiring cells?

Answer 6

red blood cells - haemoglobin within these cells can bind 4 oxygen molecules as oxyhaemoglobin

Question 7

How is carbon dioxide carried away from respiring cells?

Answer 7

as hydrogen carbonate ions

Question 8

What is internal respiration ?

Answer 8

cellular respiration in the tissues the combines oxygen and glucose to produce ATP for cellular processes and carbon dioxide as a by product

Question 9

When does anaerobic respiration occur?

Answer 9

When the demand for oxygen exceed the supply - this respiration produces ATP but also lactic acid as a by-product