Texas Respiratory Therapy Certification Exam
—Practice Questions Covering Respiratory
Therapy Knowledge, Patient Care, Diagnostics,
Mechanical Ventilation, Pharmacology,
Neonatal/Pediatric Care, And Professional
Practice.
Which structure is the primary site of gas exchange in the
lungs?
A. Trachea
B. Bronchi
C. Alveoli
D. Larynx
Correct Answer: C. Alveoli
Rationale: Alveoli are thin-walled air sacs surrounded by
pulmonary capillaries where oxygen and carbon dioxide are
exchanged.
What is the primary muscle of inspiration?
,A. Diaphragm
B. Abdominal muscles
C. Internal intercostals
D. Sternocleidomastoid
Correct Answer: A. Diaphragm
Rationale: Contraction of the diaphragm increases thoracic
volume and creates the pressure gradient required for
inspiration.
Which gas normally has the greatest partial pressure in
atmospheric air?
A. Oxygen
B. Carbon dioxide
C. Nitrogen
D. Helium
Correct Answer: C. Nitrogen
Rationale: Nitrogen makes up approximately 78% of dry
atmospheric air.
What is the normal adult respiratory rate at rest?
A. 4–8 breaths/min
,B. 12–20 breaths/min
C. 24–32 breaths/min
D. 35–45 breaths/min
Correct Answer: B. 12–20 breaths/min
Rationale: A resting respiratory rate of approximately 12–20
breaths per minute is considered normal for most adults.
Which blood component carries most oxygen?
A. Plasma
B. Platelets
C. Hemoglobin
D. White blood cells
Correct Answer: C. Hemoglobin
Rationale: Most oxygen is transported bound to hemoglobin
within red blood cells.
What is the primary function of pulmonary surfactant?
A. Increase airway resistance
B. Reduce alveolar surface tension
C. Increase mucus production
, D. Increase blood viscosity
Correct Answer: B. Reduce alveolar surface tension
Rationale: Surfactant reduces surface tension and helps
prevent alveolar collapse, particularly during expiration.
Which condition is characterized by reversible airway
obstruction and bronchial hyperresponsiveness?
A. Asthma
B. Pulmonary fibrosis
C. Emphysema
D. Pleural effusion
Correct Answer: A. Asthma
Rationale: Asthma commonly involves variable and reversible
airflow obstruction, inflammation, and airway
hyperresponsiveness.
Which finding is commonly associated with emphysema?
A. Increased elastic recoil
B. Destruction of alveolar walls
C. Increased surfactant production
D. Reduced lung compliance
—Practice Questions Covering Respiratory
Therapy Knowledge, Patient Care, Diagnostics,
Mechanical Ventilation, Pharmacology,
Neonatal/Pediatric Care, And Professional
Practice.
Which structure is the primary site of gas exchange in the
lungs?
A. Trachea
B. Bronchi
C. Alveoli
D. Larynx
Correct Answer: C. Alveoli
Rationale: Alveoli are thin-walled air sacs surrounded by
pulmonary capillaries where oxygen and carbon dioxide are
exchanged.
What is the primary muscle of inspiration?
,A. Diaphragm
B. Abdominal muscles
C. Internal intercostals
D. Sternocleidomastoid
Correct Answer: A. Diaphragm
Rationale: Contraction of the diaphragm increases thoracic
volume and creates the pressure gradient required for
inspiration.
Which gas normally has the greatest partial pressure in
atmospheric air?
A. Oxygen
B. Carbon dioxide
C. Nitrogen
D. Helium
Correct Answer: C. Nitrogen
Rationale: Nitrogen makes up approximately 78% of dry
atmospheric air.
What is the normal adult respiratory rate at rest?
A. 4–8 breaths/min
,B. 12–20 breaths/min
C. 24–32 breaths/min
D. 35–45 breaths/min
Correct Answer: B. 12–20 breaths/min
Rationale: A resting respiratory rate of approximately 12–20
breaths per minute is considered normal for most adults.
Which blood component carries most oxygen?
A. Plasma
B. Platelets
C. Hemoglobin
D. White blood cells
Correct Answer: C. Hemoglobin
Rationale: Most oxygen is transported bound to hemoglobin
within red blood cells.
What is the primary function of pulmonary surfactant?
A. Increase airway resistance
B. Reduce alveolar surface tension
C. Increase mucus production
, D. Increase blood viscosity
Correct Answer: B. Reduce alveolar surface tension
Rationale: Surfactant reduces surface tension and helps
prevent alveolar collapse, particularly during expiration.
Which condition is characterized by reversible airway
obstruction and bronchial hyperresponsiveness?
A. Asthma
B. Pulmonary fibrosis
C. Emphysema
D. Pleural effusion
Correct Answer: A. Asthma
Rationale: Asthma commonly involves variable and reversible
airflow obstruction, inflammation, and airway
hyperresponsiveness.
Which finding is commonly associated with emphysema?
A. Increased elastic recoil
B. Destruction of alveolar walls
C. Increased surfactant production
D. Reduced lung compliance
