Question 1

Which of the following does not directly affect the alveolar partial pressure of oxygen?

Accepted Answer

A) Arterial partial pressure of carbon dioxide (Paco2) 
B) Atmospheric pressure 
C) Tidal volume 
D) Fraction of inspired oxygen 
E) Oxygen consumption and carbon dioxide production (R) 
A) Arterial partial pressure of carbon dioxide (Paco2) 
B) Atmospheric pressure 
C) Tidal volume 
D) Fraction of inspired oxygen 
E) Oxygen consumption and carbon dioxide production (R) C

Question 2

In comparison with pulmonary blood flow at rest in the upright position,pulmonary blood flow when upright during exercise in normal individuals is:

Accepted Answer

A) Distributed more to the bottom of the lung than to the top. 
B) Distributed more to the top of the lung than to the bottom. 
C) Distributed essentially evenly between the top and the bottom of the lung. 
D) Is too highly variable to be determined. 
A) Distributed more to the bottom of the lung than to the top. 
B) Distributed more to the top of the lung than to the bottom. 
C) Distributed essentially evenly between the top and the bottom of the lung. 
D) Is too highly variable to be determined. C

Question 3

A patient is admitted to the hospital because of hypoxemia.While the patient breathes ambient air,the arterial partial pressure of oxygen (Pao2)is 50 mm Hg with an oxygen saturation of 82%.When the patient breathes 100% oxygen through a non-rebreathing mask,the Pao2 is 83 mm Hg with an oxygen saturation of 92%.The cause of this patient's hypoxemia is probably:

Accepted Answer

A) A physiological shunt. 
B) Low V̇/Q̇. 
C) Hypoventilation. 
D) Decreased inspired oxygen. 
A) A physiological shunt. 
B) Low V̇/Q̇. 
C) Hypoventilation. 
D) Decreased inspired oxygen. A

Question 4

When the respiratory rate is 15 breaths per minute,tidal volume is 500 mL,and anatomical dead space volume is 150 mL,what is the minute ventilation?

Accepted Answer

A) 2.25 L/minute 
B) 5.25 L/minute 
C) 7.50 L/minute 
D) 9.75 L/minute 
A) 2.25 L/minute 
B) 5.25 L/minute 
C) 7.50 L/minute 
D) 9.75 L/minute

Question 5

If the oxygen consumption is 200 mL/minute and the carbon dioxide production is 140 mL/minute,what is the respiratory quotient?

Accepted Answer

A) 60 mL/minute 
B) 0.8 
C) 0.7 
D) 143 mL/minute 
A) 60 mL/minute 
B) 0.8 
C) 0.7 
D) 143 mL/minute

Question 6

A twofold increase in the blood flow through a pulmonary arteriole is associated with:

Accepted Answer

A) No significant change in pulmonary vascular resistance. 
B) A twofold increase in pulmonary vascular resistance. 
C) A fourfold increase in pulmonary vascular resistance. 
D) A 15-fold increase in pulmonary vascular resistance. 
A) No significant change in pulmonary vascular resistance. 
B) A twofold increase in pulmonary vascular resistance. 
C) A fourfold increase in pulmonary vascular resistance. 
D) A 15-fold increase in pulmonary vascular resistance.

Question 7

The Paco2 decreases when:

Accepted Answer

A) Alveolar ventilation and CO2 production are increased and dead space is increased. 
B) Alveolar ventilation is decreased,CO2 production is unchanged,and dead space is increased. 
C) Alveolar ventilation is increased and CO2 production and dead space are decreased. 
D) Both alveolar ventilation and CO2 production are decreased and dead space is increased. 
A) Alveolar ventilation and CO2 production are increased and dead space is increased. 
B) Alveolar ventilation is decreased,CO2 production is unchanged,and dead space is increased. 
C) Alveolar ventilation is increased and CO2 production and dead space are decreased. 
D) Both alveolar ventilation and CO2 production are decreased and dead space is increased.

Question 8

An individual with early lung disease has a tidal volume of 500 mL.What is the alveolar volume if the dead space doubles and the tidal volume remains the same? (Assume that the normal ratio of dead space ventilation per minute to tidal volume [VD/VT] = 0.25.)

Accepted Answer

A) 150 mL 
B) 250 mL 
C) 300 mL 
D) 400 mL 
A) 150 mL 
B) 250 mL 
C) 300 mL 
D) 400 mL

Question 9

Which of the following is not a primary cause of hypoxemia (low oxygen level in the blood)?

Accepted Answer

A) Anatomical shunt 
B) Physiological shunt 
C) Low V̇/Q̇ 
D) Increased dead space 
A) Anatomical shunt 
B) Physiological shunt 
C) Low V̇/Q̇ 
D) Increased dead space

Question 10

When alveolar ventilation (VA)is reduced from 5 L/minute to 2.5 L/minute,the Paco2 changes from 40 mm Hg to:

Accepted Answer

A) 20 mm Hg. 
B) 60 mm Hg. 
C) 80 mm Hg . 
D) 100 mm Hg. 
E) 250 mm Hg. 
A) 20 mm Hg. 
B) 60 mm Hg. 
C) 80 mm Hg . 
D) 100 mm Hg. 
E) 250 mm Hg.

Exam 23: Ventilation

Which of the following does not directly affect the alveolar partial pressure of oxygen?

In comparison with pulmonary blood flow at rest in the upright position,pulmonary blood flow when upright during exercise in normal individuals is:

When the respiratory rate is 15 breaths per minute,tidal volume is 500 mL,and anatomical dead space volume is 150 mL,what is the minute ventilation?

If the oxygen consumption is 200 mL/minute and the carbon dioxide production is 140 mL/minute,what is the respiratory quotient?

A twofold increase in the blood flow through a pulmonary arteriole is associated with:

The Paco2 decreases when:

An individual with early lung disease has a tidal volume of 500 mL.What is the alveolar volume if the dead space doubles and the tidal volume remains the same? (Assume that the normal ratio of dead space ventilation per minute to tidal volume [VD/VT] = 0.25.)

Which of the following is not a primary cause of hypoxemia (low oxygen level in the blood)?

When alveolar ventilation (VA)is reduced from 5 L/minute to 2.5 L/minute,the Paco2 changes from 40 mm Hg to:

Principles of Cell Function

Homeostasis of Body Fluids

Signal Transduction, membrane Receptors, second Messengers, and Regulation of Gene Expression

The Nervous System: Introduction to Cells and Systems

Generation and Conduction of Action Potentials

Synaptic Transmission

The Somatosensory System

The Special Senses

Organization of Motor Function

Higher Functions of the Nervous System

The Autonomic Nervous System and Its Central Control

Skeletal Muscle Physiology

Cardiac Muscle

Smooth Muscle

Overview of Circulation

Elements of Cardiac Function

Properties of the Vasculature

Regulation of the Heart and Vasculature

Integrated Control of the Cardiovascular System

Structure and Function of the Respiratory System

Static Lung and Chest Wall Mechanics

Dynamic Lung and Chest Wall Mechanics

Oxygen and Carbon Dioxide Transport

Control of Respiration

Non-Physiologic Functions of the Lung: Host Defense and Metabolism

Functional Anatomy and General Principles of Regulation in the Gastrointestinal Tract

The Cephalic, oral, and Esophageal Phases of the Integrated Response to a Meal

The Gastric Phase of the Integrated Response to a Meal

The Small Intestinal Phase of the Integrated Response to a Meal

The Colonic Phase of the Integrated Response to a Meal

Transport and Metabolic Functions of the Liver

Elements of Renal Function

Solute and Water Transport Along the Nephron: Tubular Function

Control of Body Fluid Osmolality and Volume

Potassium, calcium, and Phosphate Homeostasis

Role of the Kidneys in the Regulation of Acid-Base Balance

Introduction to the Endocrine System

Hormonal Regulation of Energy Metabolism

Hormonal Regulation of Calcium and Phosphate Metabolism

The Hypothalamus and Pituitary Gland

The Thyroid Gland

The Adrenal Glands

The Male and Female Reproductive Systems

Filters

The Paco₂ decreases when:

An individual with early lung disease has a tidal volume of 500 mL.What is the alveolar volume if the dead space doubles and the tidal volume remains the same? (Assume that the normal ratio of dead space ventilation per minute to tidal volume [V_D/V_T] = 0.25.)

When alveolar ventilation (V_A)is reduced from 5 L/minute to 2.5 L/minute,the Paco₂ changes from 40 mm Hg to: