Gaseous Exchange

Question 1

What does the breathing system do?

Answer 1

It takes are into and out of the body so that oxygen in the air can diffuse into the blood stream and CO2 can diffuse out of the bloodstream into the air

Question 2

What is ventilation?

Answer 2

It is the movement of air into and out of the lungs

And it occurs due to changes of pressure in the lungs

Question 3

What is the process of inhalation?

Answer 3

During inhalation, the diaphragm contracts pulling down so that it flattens
The intercostal muscles contract, lifting the ribs up and out
This expands the volume of the chest cavity
This reduces the pressure below atmospherical, drawing air into the lungs from outside

Question 4

What is the process of exhalation?

Answer 4

During exhalation, the diaphragm relaxes pushing up to become domed
The intercostal muscle releases, pulling the ribs down and inwards
This reduces the volume of the chest cavity
This increase the pressure above atmospheric, releasing air from the lungs to outside the body

Question 5

What happens on inhalation?

Answer 5

Air passes down the trachea, bronchi and bronchioles until it reaches the aveoli
Here, the oxygen diffuses into the blood and CO2 diffuses out

Question 6

What are the well adaptations of the exchange system?

Answer 6

The large surface area of the avionics allows rapid diffusion of gasses
Ventilation and a good capillary blood supply maintain a steep diffusion gradient for rapid diffusion
A thin alveolar wall gives the shortest diffusion distance for gases

Question 7

Which structures increase the surface area in the lungs?

Answer 7

Alveoli (air sacs)

Question 8

Describe the position of the lungs in a human body

Answer 8

The lungs are in the upper part of the body (thorax) protected by the rib cage and separated from the lower part of the body (abdomen) by the diaphragm

Question 9

Which muscles contract when you breath in?

Answer 9

Intercostal muscles and diaphragm