CH 10: Pulmonary System

Question 1

Name and characterize the two functions of the Pulmonary System.

Answer 1

Ventilation: The movement of air in and out of the system.

Respiration: The gas exchange between oxygen and CO2.

Question 2

During Inspiration, the diaphragm _______ while the lungs and thoracic cavity ________. This creates _________ pressure, causing air to move ________ the lungs.

Answer 2

1.) Contracts
2.)Expand
3.) Negative
4.) Into

Question 3

Identify what volume and pressure changes occur during each phase of ventilation.

Answer 3

Inspiration:
Thoracic volume increases and pressure decreases
Abdominal volume decreases and pressure increases

Vice Versa during Expiration

Question 4

True or False? The ventilatory threshold usually occurs at the same time and can be used as an estimation of lactate threshold.

Answer 4

True

Question 5

Explain why expired ventilation increases in a nonlinear fashion while the increase in oxygen uptake is linear as exercise intensity increases.

Answer 5

As exercise intensity increases, an increase in non-metabolic CO2 to clear H+ results in an increase in Expired Ventilation.

Question 6

True or False? As altitude increases, the percentage of oxygen in the air decreases.

Answer 6

False: The percentage of oxygen stays the same, but the barometric pressure decreases as altitude increases.

Question 7

What is represented as PO2?

Answer 7

The Partial Pressure of Oxygen in the air.
(Measured as mmHg).

Question 8

As heart rate increases during exercise, what is one problem that many endurance athletes may experience?

Answer 8

Working at a fast heart rate for a long period can cause oxygen desaturation where it is difficult for full gas exchange to occur as blood flow is moving very quickly.

Question 9

What occurs in the lungs when an individual has pneumonia?

Answer 9

Mucus and puss clog the alveolar sacs, preventing proper gas exchange.

Question 10

Explain the advantage of the Bohr Effect when it comes to skeletal muscle during exercise.

Answer 10

Lower blood pH (more acidic) causes a higher rate of O2 unloading from hemoglobin. As exercise continues, muscle sites become more acidic due to H+ release resulting in higher rates of Oxygen diffusion.

Question 11

True or False? An increase in blood temperature has a similar effect on Oxygen offloading in skeletal muscle as the Bohr effect.

Answer 11

True

Question 12

True or False? Increased CO2 levels during exercise cause a decrease in Oxygen uptake as they take up binding space on Hemoglobin.

Answer 12

False: CO2 does not compete with O2 Hb Binding as O2 binds to the heme portion while CO2 binds to the protein (-globin) portion of Hb.

Question 13

What percentage of CO2 is bound to and transported by Hemoglobin?

Answer 13

20-33%

Question 14

Explain 2 advantages of how PCO2 levels (Partial CO2) effect CO2 -Hb Binding.

Answer 14

1.) Increased PCO2 allows for easier CO2-Hb Binding which helps exercising muscles offload CO2.

2.) Decreased levels of PCO2 allow for easier disassociation of CO2 and Hb which helps with exhalation of CO2.

Question 15

The Average alveolar surface area in the lungs is about ____ which is about 1/2 the size of a tennis court. With only _____ of blood being in the Lungs at one time, this means that there is _______ space for ___ ________. Because of this, Ve, or _____________ ___________, is not a limiting factor during exercise in most individuals.

Answer 15

1.) 50m^2
2.) 1L
3.) Extra, More than enough, Ample, etc.
4.) Gas Exchange
5.) Ventilatory Exchange

Question 16

During VO2 max testing, most individuals only reach __ -__% of their MVV, also known as _______ _________ ___________.

Answer 16

1.) 70-80%
2.) Maximum Voluntary Ventilation

Question 17

List 2 significant factors that effect MVV

Answer 17

1.) Openness of airways
2.) Respiratory Assistor Muscles

Question 18

What is normal atmospheric pressure, intrapulmonic pressure, and intrapleural pressure?

Answer 18

Atmospheric Pressure = 760mmhg
Intrapulmonic Pressure = 760mmhg
Intrapleural Pressure = 756mmhg

Question 19

What is the “act of ventilation”?

Answer 19

It creates a pressure gradient that allows air to flow in and back out during EXHALE.

Question 20

What is the principal job at rest for the diaphragm and how does it do that?

Answer 20

Alter the volume of the thoracic cage to increase the volume to decrease the pressure inside. (Vice Versa)

The contraction of the diaphragm pulls down the thoracic cage or thorax increasing the volume and lowering pressure, creating the pressure gradient to allow air to flow inward.

Question 21

Fill in the blanks.

During expiration, the lung volume ______________, thereby forcing air _______ of the lung.

Answer 21

Decreases
Out

Question 22

Explain the mechanics of an exhalation.

Answer 22

Reducing the thoracic cavity volume to increase its pressure to create an atmospheric pressure gradient allowing for air to flow outward.

This is done by the relaxation of the diaphragm muscle, elastic recoil of the thoracic cage at rest, and incorporation of respiratory assisting muscles by pulling the ribs to decrease or increase.

Question 23

Define the volume of air moving in and out of the lungs and the two components that make it up.

Answer 23

Ventilation.
Tidal Volume (TV) x Breathing rate (BR)

Question 24

Explain how Ventilation increases through Tidal volume and Breathing rate as the exercise starts and as the intensity increases.

Answer 24

Ventilation will initially increase through tidal volume (how deeply we breathe) as exercise starts. When exercise progresses the tidal volume will also increase and when the intensity changes closer to VO2 max breathing rate will also cause ventilation to go up.

Question 25

True or false?
A ventilatory threshold does not coincide with your lactate threshold.

Answer 25

False, There is a both consistent and proportional increase in ventilation and lactate threshold, and at some point, it will increase more rapidly than before.

Question 26

Is ventilation the same as oxygen consumption?

Answer 26

Oxygen consumption increases in a straight positive linear fashion when you increase workload or power, where ventilation is non-linear with a steeper rise in higher exercise intensities which reflects the non-metabolic CO2 that is formed to buffer hydrogen ions. (HCO3-)

Question 27

True or false.
We have CO2 sensors inside our heart and blood vessels that alert the brain to expel the remaining non-metabolic CO2 when sensing an increase in CO2 inside the body.

Answer 27

True, this explains a way on how ventilation increases.

Question 28

What makes the atmospheric pressure and the partial pressures that make it up?

Answer 28

Nitrogen, Oxygen, and CO2.
Nitrogen = 600.7mmhg
Oxygen = 159.1 mmhg
Carbon Dioxide = 0.2 mmhg

Question 29

What are the PO2 and PCO2 inside the alveoli, the systemic arteries, and the systemic veins?

Answer 29

Alveoli
PO2 = 105mmhg
PCO2 = 40mmhg

Systemic Arteries
PO2 = 100mmhg
PCO2 = 40mmhg

Systemic Veins
PO2 = 40mmhg
PCO2 = 46mmhg

Question 30

What variables influence the diffusion of gasses through a tissue?

Answer 30

The partial pressures and pressure gradient (Dependent on altitude)
Thickness of the tissue

Question 31

What is the diffusion gradient when at a higher altitude?

Answer 31

42 (Arterial blood) - 27 (Venous blood) = 15mmhg

Question 32

What happens to (A-VO2) Difference between rest to exercise?

Answer 32

(A-VO2) Difference will increase as we begin the exercise, where at rest there is 4-5ml of O2 diffusing into the capillaries, whereas when exercising there is 15 ml of O2 being diffused.

This also means that the amount of O2 left after diffusion from the capillaries to the veins will decrease as exercise increases.

Question 33

Fill in the blanks.

When CO2 leaves the tissues and enters the blood combines with ______ to form __________ ___________. This process occurs in the _____ ________ _______ which is catalyzed by an enzyme called __________ ____________.

Answer 33

Water (H20)
Carbonic Acid
Red blood cells
Carbonic Anhydrase

Question 34

When carbonic acid is formed explain the process of how it releases a hydrogen ion.

Answer 34

Carbonic acid will dissociate into bicarbonate and a hydrogen ion which then will circulate the body until it gets to the lungs or kidneys to expel the CO2. The protons (Hydrogen) that form from this trigger the Bohr effect creating cellular respiration.

Question 35

Consider a sub-max run at 40% of your VO to Max at sea level versus a 40% VO2 max run at altitude why is it harder to run the altitude?

Answer 35

The air pressure is less at altitude which means that the pressure gradient for oxygen drop-off is reduced because we have reduced the pressure gradient between the atmospheric air, the air in our lungs, and the PO2 in our muscle cells.

Question 36

What type of CO2 is responsible for 10%, 20%, and 70% of the CO2 diffused into the Alveoli?

Answer 36

10%: The CO2 that was dissolved in the blood plasma.
20%: The CO2 that was traveling in the RBC as Carbaminohemoglobin
70%: The CO2 that was traveling as bicarbonate

Question 37

Explain why a chloride shift occurs.

Answer 37

Bicarbonate is a negatively charged ion and when diffusing out of the RBC it will disrupt the electrical balance. Our body will then replace the missing negative ion with a chloride ion from the plasma to balance the electrical charge explaining a “chloride shift”.

Question 38

Fill in the blanks.
Around ____ - ______ % of endurance athletes experience something called, “desaturation”. Where their blood becomes more _________ gradually because there is not a good balance between ____________ and ____________.

Answer 38

40-50
Deoxygenated
Perfusion
Ventilation

Question 39

How does ventilation play a role as a performance limiter?

Answer 39

For elite endurance athletes, their Q (Cardio output) is very high. This can cause a potential mismatch between diffusion and ventilation, especially when the respiratory assistor muscles fatigue.

What is happening is that blood is flowing so fast through capillaries in the lungs and ventilation is occurring frequently there

Question 40

What impact does the falling PO2 in Pulmonary capillaries have on the oxygen content of blood and the Fick equation?

Answer 40

Affects the oxyhemoglobin saturation as this is the primary variable that determines how well hemoglobin gets saturated with oxygen which is the main way oxygen travels around the body.

In the Fick equation, the A is going to be lower creating a smaller (A-VO2) difference that results in a lower VO2 which reduces oxidative metabolism leading to fatigue.

Question 41

In a working muscle will the PCO2 be high or low?

Answer 41

High because of metabolism producing metabolic CO2 and possibly some non-metabolic CO2 as well from the bicarbonate buffer