Revision PPQ'S Respiratory System

Question 1

Describe how the medulla oblongata increases breathing rate:

Answer 1

It increases the frequency of the signals and then respiratory muscles contract faster

Question 2

Describe the mechanism of breathing for expiration at rest.

Answer 2

The internal intercostals and diaphragm relax which brings the rib cage down and in, this increases the pressure in the thoracic cavity and air is forced out

Question 3

Describe the process of gaseous exchange at the alveoli:

Answer 3

At the alveoli oxygen moves from the alveoli into the blood because of diffusion and gases always move from an area of high concentration (in the alveoli) to an area of low concentration (blood capillaries)
Carbon dioxide moves from the blood capillaries (high concentration) into the alveoli (low concentration)