Respiratory System

Question 1

Spirometry

Total lung volume

Answer 1

Question 2

Spirometry

Tidal volume

Answer 2

Question 3

Spirometry

Functional residual capacity

Answer 3

Question 4

Spirometry

Residual volume

Answer 4

Question 5

Spirometry

Inspiratory and expiratory reserve volume

Answer 5

Question 6

Spirometry

Vital capacity

Answer 6

Question 7

Graph of Spirometry

Total lung volume
Sum of all volumes in the lungs.
Note that this can not be measured by spirometry (only lung capacity can be measured).

Tidal volume
Volume of a normal breath.

Functional residual capacity
Volume left in lungs after a natural exhalation.

Residual volume
Volume left in lungs after a full forced exhalation. In order to keep alveoli open, the lung cannot fully deflate, resulting in residual volume

Inspiratory and expiratory reserve volume
Additional volume that can be inhaled after a natural breath in, or exhaled after a natural breath out.

Vital capacity
Volume of a full forced inhalation and exhalation. Equals the total lung capacity minus the residual volume.

Answer 7

Question 7

Nostrils of nose, which contain nose hairs called vibrissae that help protect from pathogens.

Answer 7

Nares

Question 8

Connects the mouth to the esophagus.
Allows passage of both air and food.

Answer 8

Pharynx

Question 9

Connects the mouth to the trachea.
Allows air, but food is blocked by the epiglottis.

Answer 9

Larynx

Question 10

Central airway. Branches into two bronchi.

Answer 10

Trachea

Question 11

Branch of the airway which enters into each lung. Branches further into bronchioles.

Answer 11

Bronchi

Question 12

The lining around the lungs. Allows movement with minimal friction.

Answer 12

Pleura

Question 13

Bicarbonate buffer equation

Answer 13

CO2 + H2O ⇌ H2CO3 ⇌ H+ + HCO3-

Question 14

Application of Le Chatelier’s principle to blood gas physiology

Answer 14

To regulate blood pH, the body will change respiration rate which affects the blood CO2 concentration.
This shifts the equilibrium of the bicarbonate buffer system to modulate H+ concentration.

Question 15

If the blood pH is too low, the body will compensate by increasing respiration rate to blow off more CO2.

Answer 15

Blood acidosis

Question 16

If the blood pH is too high, the body will compensate by decreasing respiration rate to blow off less CO2.

Answer 16

Blood alkalosis

Question 17

Breathing mechanisms

Differential pressure

Intrapulmonary pressure vs Intrapleural pressure

Answer 17

Intrapulmonary pressure: same as atmospheric pressure because lung is open to outside.

Intrapleural pressure: lower than atmospheric pressure to keep lung from collapsing.

Question 18

Occurs through negative pressure mechanism.
The diaphragm muscle pulls downward, decreasing intrapleural pressure and causing lung expansion.

Answer 18

Inhalation

Question 19

Usually a passive process due to muscle relaxation.
Active exhalation recruits the intercostal muscles to help force air out.

Answer 19

Exhalation

Question 20

Alveoli are coated with surfactant which helps decrease surface tension, preventing collapse.

Answer 20

Surface tension

Question 21

Respiratory control center of brain is the

Answer 21

Respiratory control center of brain is the medulla oblongata.
When blood pH is acidic, respiration increases to blow off CO2 and increase bicarbonate buffer.

Question 22

Amount of CO2 produced per O2 consumed.

Answer 22

Respiratory quotient