Exam 4 study guide Pt. 2

Question 1

What is intrapleural pressure?

Answer 1

Intrapleural pressure is the pressure found within the pleura cavity, rises and falls with inspiration and expiration.

Question 2

Intrapulmonary pressure?

Answer 2

intrapulmonary pressure is the pressure within the alveoli, it rises and falls with inspiration and expiration.

Question 3

Describe Boyle’s law.

Answer 3

A gas law that states that pressure and volume have an inverse relationship, meaning that as volume increases pressure will decrease, and the opposite is true as well as volume decreases the pressure will increase.

Question 4

Describe the muscles activated with inspiration.

Answer 4

Inspiratory muscles increase the volume of the lungs, and they are the diaphragm muscle and external intercostal muscles.

During inspiration these two muscles contract, the contraction of the diaphragm muscle causes the thorax to increase in height and the diameter and lungs increases in volume.

The contraction of the external intercostal muscles causes the thorax to increase in diameter and lungs to increase in volume.

Question 5

What happens during pressure and volume changes with inspiration & expiration? What happens during pressure and volume changes with inspiration & expiration?

Answer 5

During inspiration, the inspiratory muscles contract, which increases volume and interpulmonary pressure decreases; during expiration lung volume decreases and interpulmonary pressure increases.

Question 6

What is surface tension?

Answer 6

In gas-water boundary, the water molecules are more attracted to one another than the nonpolar gas molecules, this attraction water molecules to cluster together to form hydrogen bonds.

This creates at state of surface tension.

Question 7

Describe surfactant and its importance

Answer 7

Surfactant is an amphiphilic chemical produced by type II alveolar cells that disrupts hydrogen bonds between water molecules, reducing surface tension.

Question 8

What is lung compliance? What determines this? (2 factors)

Answer 8

Is the ability of the lungs and the chest wall to stretch known as distensibility. It’s determined by degree of alveolar surface tension, distensibility of elastic tissue in the lungs, and the ability of the chest wall to move.

Question 9

Describe the 4 respiratory volumes we discussed in class.

Answer 9

Tidal volume (TV)
Inspiratory reserved volume (IRV)
Expiratory reserved volume (ERV)
Residual volume (RV)

Question 10

Describe Tidal volume (TV).

Answer 10

Tidal volume (TV) is the volume of air exchanged with normal quiet breathing.

Question 11

Describe Inspiratory reserved volume (IRV).

Answer 11

Inspiratory reserved volume (IRV) is the maximal volume of air that can be forcibly inspired after TV.

Question 12

Describe Expiratory reserved volume (ERV)

Answer 12

Expiratory reserved volume (ERV) is the amount of air expelled after a normal TV expiration.

Question 13

Describe Residual volume (RV)

Answer 13

Residual volume (RV) is the volume of air that remains in the lungs after a forced expiration.

Question 14

What are the various respiratory capacities? (4)

Answer 14

Inspiratory capacity
Functional residual capacity
Vital Capacity
Total lung capacity

Question 15

Describe Inspiratory capacity

Answer 15

inspiratory capacity that is the total amount of air a person can inspire after a tidal respiration.

Question 16

Describe Functional residual capacity

Answer 16

Functional residual capacity that is the amount of air that is normally left in the lungs after a tidal inspiration.

Question 17

Describe Vital capacity

Answer 17

Vital capacity represents the total amount of air that can be move in and out of the lungs.

Question 18

Describe total lung capacity

Answer 18

Total lung capacity represents the total amount of exchangeable air and nonexchangeable air in the lungs.

Question 19

What is a spirometer?

Answer 19

A laboratory instrument that measures volume of air exchanged with ventilation.

Question 20

What do spirometry tests indicate?

Answer 20

It shows a record of a person’s normal and forceful inspirations and expirations.

Question 21

Define Dalton’s law of partial pressure

Answer 21

A gas law stating that the total pressure of a container is equal to the sum of partial pressures of the gases in the mixture.

Question 22

What is Henry’s law?

Answer 22

Henry’s law states that the degree to which a gas dissolves in a liquid is proportional to both its partial pressure and its solubility in the liquid.

Question 23

How does Henry’s law relate to respiration?

Answer 23

It relates to respiration because it predicts how gasses will dissolve in the alveoli and bloodstream during gas exchange.

Question 24

Describe the general pressure differentials and relationships with pulmonary gas exchange (external respiration).

Question 25

Describe the general pressure differentials and relationships with tissue gas exchange (internal respiration).

Question 26

What is ventilation-perfusion coupling?

Answer 26

Is the relationship between the degree of match between the amount of air reaching the alveoli (ventilation), and the amount of blood flow in the pulmonary capillaries (perfusion).

Changes in ventilation lead to changes in perfusion, so blood flow is directed to areas with the most oxygen and changes in the efficiency of perfusion lead to changes in the amount of ventilation, so air flow is directed to areas with the most blood flow.

Question 27

How is oxygen transported in the blood?

Answer 27

Most oxygen is transported on the protein hemoglobin.

Question 28

How does unloading of oxygen cause pH changes?

Answer 28

A decreased affinity of hemoglobin to oxygen leading to unloading leads to a decrease in pH.

Question 29

What is the oxygen-hemoglobin dissociation curve?

Answer 29

A graphic representation of the relationship between the partial pressure of oxygen in the blood and the degree of saturation of hemoglobin.

Question 30

What causes the curve to shift right? Where does this happen?

Answer 30

The right shift in the association curve happens in the systemic circuit and causes a decrease in the affinity of hemoglobin affinity for oxygen.

Question 31

What causes the curve to shift left? Where does this happen?

Answer 31

The left shift in the association curve happens in the lungs and is caused by an increase in the affinity of hemoglobin to oxygen.

Question 32

What is hypoxia?

Answer 32

Is an absence of enough oxygen in the tissues to sustain bodily functions.

Question 33

How is carbon dioxide transported in the body?

Answer 33

Dissolved in plasma, bound to hemoglobin within erythrocytes, and as bicarbonate ions in blood.

Question 34

What is the function of carbonic-acid-bicarbonate buffer system?

Answer 34

The major buffer system in the blood that prevents the blood pH to change majorly disturbing body homeostasis.

It happens because hydrogen ions bind with buffers such as bicarbonate ions to form carbonic acid to prevent hydrogen ions from disturbing the pH range.

When blood pH increases and the levels of hydrogen ions drop too low, hydrogen ions are released from carbonic acid to bring pH back down to the normal range.

Question 35

What happens to pH of blood during hypoventilation?

Answer 35

Hypoventilation causes the retention of carbon dioxide and increases the blood’s partial pressure of CO2. This results in in carbonic acid releasing more hydrogen ions decreasing the blood pH.

Question 36

What happens to pH of blood during Hyperventilation?

Answer 36

During hyperventilation:
- the amount of carbon dioxide that is being expired increases and leads to the decrease the blood partial pressure of carbon dioxide.

• As a result, carbonic acid can release fewer hydrogen ions and the pH of blood increases.
• It also raises the amount of oxygen in the lungs, which causes more oxygen to dissolve in plasma.

Question 37

What is the Haldane effect?

Answer 37

At higher partial pressure, the oxygenation of the blood in the lungs displaces CO2 from hemoglobin which increases the removal of CO2.

Question 38

What is the Bohr effect?

Answer 38

As temperature, acidity, and partial pressure of CO2 decrease, hemoglobin binds oxygen more strongly and less oxygen is being unloaded.

Question 39

What areas of the brainstem control respiration?

Answer 39

the medulla oblongata, and a collection of neurons called the respiratory pattern generator (RPG) that generates the basic rhythm for breathing located in the superior anterior medulla.

Question 40

What are chemoreceptors?

Answer 40

Special nerve cells that detect changes in the chemical composition of the blood and send information to the brain to regulate respiratory functions.

The two types of chemoreceptors involved in the control of ventilation are central and peripheral.

Question 41

How does altitude impact respiration?

Answer 41

Higher altitudes have lower atmospheric pressure with lower levels of oxygen, and less oxygen will be diffused into the blood lowering the rate and depth of breathing.

High altitude acclimation, where the rate of elevation is increased over days instead of hours, allows peripheral receptors to “acclimate” to the higher altitudes and increase the rate and depth of breathing.