Pressure changes that facilitate breathing. Answer all of the following MCQs and leave your answers in the comments section for marking.

During exhalation and before the onset of inhalation the intrapleural pressure is;
a. 0 mm Hg
b. 2 mm Hg
c. 4 mm Hg.
d. 6 mm Hg

During inhalation the intrapleural pressure is;
a. 0 mm Hg
b. 2 mm Hg
c. 4 mm Hg
d. 6 mm Hg

Which of the following is an accessory muscle of ventilation?
a. sternocleidomastoid
d. diaphragm
c. external intercostals
d. myocardium

During the process of inspiration the;
a. diaphragm contracts and moves downward.
b. diaphragm contracts and moves upwards
c. diaphragm relaxes and moves downward
d. diaphragm relaxes and moves upwards

During the process of inspiration the;
a. external intercostal muscles relax and move the diaphragm upwards
b. external intercostal muscles relax to allow the chest wall to move up and out
c. the external intercostal muscles contract and move the chest wall down and in
d. the external intercostal muscles contract and move the chest wall up and out

Which statement about the ribs is true?
a. men have 12 pairs of ribs and women have 11 pairs
b. men have 11 pairs of ribs and women have 12 pairs
c. ten pairs of ribs are connected to the sternum by costal cartilage
d. all of the ribs are directly attached to the sternum by the costal cartilage

Which statements about inspiration is true?
a. air is blown into the lungs using positive pressure ventilation
b. air is sucked into the lungs using negative pressure ventilation.
c. the diaphragm moves upwards
d. air enters the lungs as a result of the passive recoil of the elastic walls of the alveoli

Identify one true statement:
a. intrapulmonary pressure is lower than atmospheric pressure during expiration
b. intrapulmonary pressure is higher than atmospheric pressure during inspiration
c. intrapulmonary pressure is the same as the pressure in the alveoli.
d. intrapulmonary pressure is higher than the pressure in the alveoli
e. intrapulmonary pressure is lower than the pressure in the alveoli