How respiration takes place.

Question 1

This is the flow of air between the atmosphere and the lungs, occurs due to differences in air pressure.

Answer 1

Pulmonary Ventilation:

Question 2

quiet (unforced) inhalation

What nerve sends impulses to contract the diaphram?

Answer 2

phrenic nerves.

Question 3

quiet (unforced) inhalation

What is happening to the lung volume when the diaphram contracts and flattens?

Answer 3

The lung volume expands, thus pulling the ribs
upward and outward, and further increasing lung volume.

Question 4

quiet (unforced) inhalation

Contraction of the diaphragm is responsible for about % of the air that enters the lungs during quiet breathing.

Answer 4

75%

Question 5

quiet (unforced) inhalation

Advanced pregnancy, obesity, confining clothing, or increased size of the stomach after eating a large meal can

Answer 5

impede descent of the diaphragm and may cause shortness of breath.

Dumb Question?

Question 6

External intercostal muscles contract:

During deep, labored inhalations, what structures are being utilized to increase lung size?

Answer 6

1. Sternocleidomastoid muscles elevated the sternum
2. the scalene muscles elevate the two uppermost ribs
3. and pectoralis minor muscles elevate the third through fifth ribs

Question 7

is what occurs due to elastic recoil of the chest wall and lungs, both of which have a natural tendency to spring back after they have been stretched.

in addition, alveoli and airways don’t completely collapse due to this recoil effect and the presence of surfactant.

Answer 7

Exhalation

Question 8

Diaphragm and external intercostal.

Because no muscular contractions are involved, quiet exhalation, unlike quiet inhalation this is what process?

Answer 8

is a passive process and the diaphragm and external intercostal
relax.

Question 9

During forced exhalation, muscles of exhalation are:

These group of muscles contract to move the lower ribs downward and compress the abdominal viscera, thus forcing the diaphragm upward.

Answer 9

a) Internal intercostal
b) External oblique
c) Internal oblique
d) Transverse abdominis
e) Rectus abdominis

Question 10

Lung expansion causes air molecules within the lungs to occupy a larger volume, causing the air pressure inside to

Answer 10

decrease.

Question 11

When lung volume decreases,

Answer 11

the alveolar pressure increases.

Question 12

At rest just before inhalation, the air pressure inside the lungs is the

Answer 12

same as the pressure of the atmosphere (760 mm Hg at sea level).

Question 13

As the diaphragm and external intercostal contract and the overall size of the thoracic cavity increases, the volume of the lungs

Answer 13

increases and alveolar
pressure decreases from 760 to 758 mm Hg.