Final: AP2 8 May 25 Final Review

Question 1

What is the relationship between pH and proton concentration?

Answer 1

A pH of 1 corresponds to a proton concentration of 0.1 moles per liter

A pH scale measures acidity; lower pH means higher proton concentration.

Question 2

How do you calculate the concentration of O2 in the lungs?

Answer 2

Concentration of O2 = (partial pressure of O2) / (total pressure)

Use the partial pressure of O2 at FRC to estimate concentration.

Question 3

What is the typical alveolar O2 concentration at FRC in a healthy adult?

Answer 3

Approximately 13.16%

This value is used in calculations to estimate O2 volume in the lungs.

Question 4

What is the expected bicarbonate level in a patient with metabolic acidosis due to uncontrolled diabetes?

Answer 4

Reduced bicarbonate level

The body attempts to buffer excess acid, resulting in lower bicarbonate.

Question 5

What is the anion gap and how is it calculated?

Answer 5

Anion gap = (sodium concentration) - (chloride concentration + bicarbonate concentration)

A normal anion gap is around 12; an increased anion gap indicates metabolic acidosis.

Question 6

True or False: In metabolic acidosis, the respiratory system compensates by decreasing ventilation.

Answer 6

False

The respiratory system increases ventilation to blow off CO2 and help restore pH balance.

Question 7

What effect does intrapulmonary shunting have on arterial blood gas values?

Answer 7

Decreases PAO2 and may increase PCO2

Intrapulmonary shunting can lead to hypoxemia and respiratory acidosis.

Question 8

What happens to titratable acid excretion in chronic uncontrolled diabetes?

Answer 8

It increases

The kidneys excrete more acid to compensate for metabolic acidosis.

Question 9

What is the expected urine bicarbonate excretion in chronic uncontrolled diabetes?

Answer 9

Lower than normal

The kidneys conserve bicarbonate in response to acidosis.

Question 10

Fill in the blank: The respiratory quotient is used to estimate the _______.

Answer 10

balance of O2 consumption and CO2 production

Question 11

How does the body respond to an increase in metabolic acidosis?

Answer 11

Increased respiratory rate to decrease CO2 levels

This helps restore acid-base balance by reducing carbonic acid levels.

Question 12

What is the primary function of the VRG in the neuro control of breathing?

Answer 12

Stimulates breathing rate

The Ventral Respiratory Group (VRG) responds to chemical signals and higher brain centers.

Question 13

What is the impact of aspirin overdose on acid-base balance?

Answer 13

Causes metabolic acidosis

Excess salicylic acid increases acidity in the body.

Question 14

What should be expected in plasma PCO2 for a patient with metabolic acidosis?

Answer 14

Lower than normal

The respiratory system compensates by hyperventilation.

Question 15

What is the expected change in plasma anion gap due to salicylic acid overdose?

Answer 15

Increased anion gap

Non-volatile acids contribute to a higher anion gap.

Question 16

What is the significance of measuring arterial blood gases?

Answer 16

To assess respiratory and metabolic function

ABG values help diagnose conditions like acidosis or alkalosis.

Question 17

What happens to the levels of CO2 during severe hypoxemia due to intrapulmonary shunting?

Answer 17

PCO2 may be elevated

Ventilation may increase, but CO2 levels can still rise if shunting is severe.

Question 18

What stimulates the VRG during breathing?

Answer 18

Both higher brain centers and chemoreceptors

The VRG (ventral respiratory group) is influenced by multiple factors including exercise and changes in blood chemistry.

Question 19

What type of breathing pattern is associated with DKA?

Answer 19

Cozumel breathing

This pattern is characterized by hyperventilation but is not classified as hyperventilation due to ongoing acidosis.

Question 20

What is the respiratory quotient (RQ) typically around?

Answer 20

0.8

The RQ indicates that we do not convert all oxygen into CO2; some oxygen is utilized in other metabolic pathways.

Question 21

What calculation can be performed based on normal breathing?

Answer 21

Respiratory quotient

Although the course may not require detailed calculations, understanding the concept is still beneficial.

Question 22

What should students focus on when reviewing graphs?

Answer 22

Identifying trends and understanding data

Students should be able to relate graphical data to normal and disease conditions.

Question 23

What is the significance of the alveolar gas equation?

Answer 23

It relates to the respiratory quotient and gas exchange

This equation helps in understanding how gases behave in the lungs.

Question 24

What is the role of peripheral chemoreceptors?

Answer 24

They analyze arterial blood gas numbers

Changes in oxygen and carbon dioxide levels trigger increased ventilation.

Question 25

What causes a decrease in arterial hemoglobin saturation?

Answer 25

Presence of methemoglobin and carbon monoxide ## Footnote These factors interfere with hemoglobin's ability to bind oxygen.

Question 26

What is the effect of a decrease in hematocrit on gas exchange?

Answer 26

It may not significantly affect PAO2 or PACO2 ## Footnote Anemia affects oxygen delivery but not necessarily the partial pressures of gases.

Question 27

How does the body compensate for increased PCO2?

Answer 27

Through renal or respiratory compensation ## Footnote Compensation mechanisms help maintain acid-base balance.

Question 28

What is the capital D in the fixed diffusion equation?

Answer 28

Diffusivity ## Footnote This value considers both solubility and molecular weight.

Question 29

What is the expected vital capacity in a healthy student?

Answer 29

Approximately 5 liters ## Footnote This is measured during maximal effort expiration after a full inspiration.

Question 30

What does curve W represent in a maximal expired flow curve?

Answer 30

Normal maximal expired flow ## Footnote This reflects healthy respiratory function.

Question 31

What can indicate the presence of asthma or aspiration in a respiratory curve?

Answer 31

A decrease in the maximal expired flow rate ## Footnote Such conditions can lead to obstructed airflow.

Question 32

Fill in the blank: The Cozumel breathing pattern is characterized by _______.

Answer 32

Hyperventilation ## Footnote This pattern occurs while the patient is still acidotic.

Question 33

True or False: The respiratory quotient is always equal to 1.

Answer 33

False ## Footnote The typical respiratory quotient is around 0.8.

Question 34

What is the impact of tracheal obstruction on airflow?

Answer 34

It can slow down the rate of air entering or leaving the lungs, depending on the severity of the blockage. ## Footnote If the trachea is completely blocked, normal airflow cannot occur.

Question 35

What is the role of PO2 in ventilation?

Answer 35

As PO2 increases, ventilation increases until it reaches a critical level around 70 mmHg, after which the response diminishes. ## Footnote This relationship is not linear, with significant changes occurring at lower PO2 levels.

Question 36

True or False: CO2 levels have a linear relationship with ventilation.

Answer 36

True ## Footnote A slight increase in CO2 leads to a slight increase in ventilation, while a massive increase results in a significant increase.

Question 37

What does the 95:5 rule refer to in CO2 content?

Answer 37

It refers to the proportion of dissolved CO2 to bicarbonate in arterial blood. ## Footnote In arterial circulation, approximately 90% of CO2 exists as bicarbonate.

Question 38

Fill in the blank: The dorsal respiratory group is also known as the _______.

Answer 38

nucleus tractus solitarius ## Footnote This region of the brain is crucial for respiratory control.

Question 39

What limits expiratory flow in restrictive lung disease?

Answer 39

Low lung volume and narrowed airways due to increased tissue recoil. ## Footnote In restrictive diseases, the inability to inflate the lungs leads to narrower airways, affecting airflow.

Question 40

What is the recommended strategy for reviewing study questions before a test?

Answer 40

Review the study questions one last time the day before or morning of the test for improved recognition. ## Footnote This approach helps reinforce familiar concepts and data.

Question 41

What happens to ventilation when arterial PCO2 rises?

Answer 41

Ventilation increases linearly in response to increased PCO2 levels. ## Footnote The sensitivity of receptors to CO2 contributes to this response.

Question 42

What is the function of the ventral respiratory group in the brain?

Answer 42

It helps control the pace of breathing. ## Footnote This group is associated with the botzinger complex and the pre-Bötzinger complex.

Question 43

What is the effect of aspiration of a foreign body into the trachea?

Answer 43

It may occlude airflow, affecting both inspiration and expiration depending on the size of the object. ## Footnote Complete obstruction would prevent normal breathing.

Question 44

What is the significance of the critical PO2 level in ventilation?

Answer 44

Breathing activity decreases significantly once PO2 exceeds approximately 70 mmHg. ## Footnote Below this level, hypoxic chemoreceptors are more active.