1.5 Ventilating the Lungs

Question 1

Name 2 things that breathing relies on

Answer 1

• the thorax

* the intercostal muscles

Question 2

What happens when we breathe in?

Answer 2

1. The intercostal muscles contract
2. The ribcage moves up and out
3. The diaphragm flattens
4. The volume of the thorax increases
5. The pressure in the thorax decreases and air is drawn in as air travels from high to low pressure

Question 3

Describe the movement of air in reference to pressure

Answer 3

Air moves from high to low pressure

Question 4

What happens when we breathe out?

Answer 4

1. The intercostal muscles relax
2. The ribcage moves down and in
3. The diaphragm becomes domed
4. The volume of the thorax decreases
5. The pressure of the thorax increases and air is forced out because

Question 5

Which muscles contract when you breathe in?

Answer 5

Intercostal muscles

Question 6

Where are the lungs situated?

Answer 6

In the thorax, inside the ribcage and above the diaphragm which separates the lungs from the abdomen