ITEC Respiratory System Ultimate Exam
Question 1. **What is the primary function of the nasal conchae?**
A) Produce mucus
B) Warm and humidify inspired air
C) Filter blood
D) Conduct sound vibrations
Answer: B
Explanation: The conchae increase surface area in the nasal cavity, allowing air to be warmed and
humidified before reaching the lower airway.
Question 2. **Which part of the pharynx is common to both the respiratory and digestive tracts?**
A) Nasopharynx
B) Oropharynx
C) Laryngopharynx
D) All of the above
Answer: B
Explanation: The oropharynx lies posterior to the oral cavity and serves as a passage for both air and
food.
Question 3. **The epiglottis prevents which of the following during swallowing?**
A) Air from entering the esophagus
B) Food from entering the trachea
C) Mucus from entering the lungs
D) Vocal cords from vibrating
Answer: B
Explanation: The epiglottis folds down over the glottis during swallowing, directing food toward the
esophagus and protecting the airway.
Question 4. **C-shaped cartilage rings in the trachea are incomplete posteriorly to allow for:**
A) Expansion of the esophagus
B) Passage of the aorta
, ITEC Respiratory System Ultimate Exam
C) Flexibility of the neck
D) Attachment of the diaphragm
Answer: A
Explanation: The open posterior part of the tracheal rings is adjacent to the esophagus, permitting its
expansion during swallowing.
Question 5. **Which structure marks the bifurcation of the trachea into the right and left main bronchi?
**
A) Carina
B) Hilum
C) Bronchus intermedius
D) Mediastinum
Answer: A
Explanation: The carina is a cartilaginous ridge at the lower end of the trachea where it splits into the
primary bronchi.
Question 6. **How many lobes does the right lung contain?**
A) Two
B) Three
C) Four
D) Five
Answer: B
Explanation: The right lung is divided into three lobes—superior, middle, and inferior—separated by
oblique and horizontal fissures.
Question 7. **Surfactant primarily reduces surface tension in the alveoli by decreasing the tendency of
the alveolar walls to:**
A) Collapse during expiration
B) Expand during inspiration
C) Leak fluid into the interstitium
, ITEC Respiratory System Ultimate Exam
D) Recruit immune cells
Answer: A
Explanation: Surfactant lowers alveolar surface tension, preventing collapse (atelectasis) especially at
low lung volumes.
Question 8. **During quiet inspiration, which muscle is the main driver of thoracic volume increase?**
A) Internal intercostals
B) Diaphragm
C) Scalenes
D) Abdominal muscles
Answer: B
Explanation: Contraction of the diaphragm flattens its dome, expanding the thoracic cavity and creating
negative intrapulmonary pressure.
Question 9. **Boyle’s law explains why air flows into the lungs during inspiration because:**
A) Pressure and volume are directly proportional
B) Pressure and volume are inversely proportional
C) Temperature remains constant
D) Gas solubility changes
Answer: B
Explanation: As thoracic volume increases, intrapulmonary pressure falls below atmospheric pressure,
causing air to move inward.
Question 10. **Which muscle group is recruited during forced expiration?**
A) External intercostals
B) Diaphragm
C) Internal intercostals and abdominal muscles
D) Scalenes
Answer: C
, ITEC Respiratory System Ultimate Exam
Explanation: Forced expiration requires active contraction of internal intercostals and abdominal
muscles to decrease thoracic volume rapidly.
Question 11. **The primary site of external respiration (gas exchange) is:**
A) Bronchi
B) Alveolar ducts
C) Alveoli
D) Trachea
Answer: C
Explanation: Alveoli have thin walls and a rich capillary network, allowing O₂ and CO₂ diffusion between
air and blood.
Question 12. **In internal respiration, oxygen diffuses from:**
A) Alveolar air to pulmonary capillary blood
B) Systemic capillary blood to tissue cells
C) Venous blood to arterial blood
D) Tissue cells to pulmonary capillaries
Answer: B
Explanation: Internal respiration refers to O₂ moving from systemic capillaries into tissue cells, and CO₂
moving in the opposite direction.
Question 13. **Which form of hemoglobin carries the majority of carbon dioxide in the blood?**
A) Oxyhemoglobin
B) Carbaminohemoglobin
C) Methemoglobin
D) Fetal hemoglobin
Answer: B
Explanation: About 20–25% of CO₂ is transported bound to the amino groups of hemoglobin as
carbaminohemoglobin.
Question 1. **What is the primary function of the nasal conchae?**
A) Produce mucus
B) Warm and humidify inspired air
C) Filter blood
D) Conduct sound vibrations
Answer: B
Explanation: The conchae increase surface area in the nasal cavity, allowing air to be warmed and
humidified before reaching the lower airway.
Question 2. **Which part of the pharynx is common to both the respiratory and digestive tracts?**
A) Nasopharynx
B) Oropharynx
C) Laryngopharynx
D) All of the above
Answer: B
Explanation: The oropharynx lies posterior to the oral cavity and serves as a passage for both air and
food.
Question 3. **The epiglottis prevents which of the following during swallowing?**
A) Air from entering the esophagus
B) Food from entering the trachea
C) Mucus from entering the lungs
D) Vocal cords from vibrating
Answer: B
Explanation: The epiglottis folds down over the glottis during swallowing, directing food toward the
esophagus and protecting the airway.
Question 4. **C-shaped cartilage rings in the trachea are incomplete posteriorly to allow for:**
A) Expansion of the esophagus
B) Passage of the aorta
, ITEC Respiratory System Ultimate Exam
C) Flexibility of the neck
D) Attachment of the diaphragm
Answer: A
Explanation: The open posterior part of the tracheal rings is adjacent to the esophagus, permitting its
expansion during swallowing.
Question 5. **Which structure marks the bifurcation of the trachea into the right and left main bronchi?
**
A) Carina
B) Hilum
C) Bronchus intermedius
D) Mediastinum
Answer: A
Explanation: The carina is a cartilaginous ridge at the lower end of the trachea where it splits into the
primary bronchi.
Question 6. **How many lobes does the right lung contain?**
A) Two
B) Three
C) Four
D) Five
Answer: B
Explanation: The right lung is divided into three lobes—superior, middle, and inferior—separated by
oblique and horizontal fissures.
Question 7. **Surfactant primarily reduces surface tension in the alveoli by decreasing the tendency of
the alveolar walls to:**
A) Collapse during expiration
B) Expand during inspiration
C) Leak fluid into the interstitium
, ITEC Respiratory System Ultimate Exam
D) Recruit immune cells
Answer: A
Explanation: Surfactant lowers alveolar surface tension, preventing collapse (atelectasis) especially at
low lung volumes.
Question 8. **During quiet inspiration, which muscle is the main driver of thoracic volume increase?**
A) Internal intercostals
B) Diaphragm
C) Scalenes
D) Abdominal muscles
Answer: B
Explanation: Contraction of the diaphragm flattens its dome, expanding the thoracic cavity and creating
negative intrapulmonary pressure.
Question 9. **Boyle’s law explains why air flows into the lungs during inspiration because:**
A) Pressure and volume are directly proportional
B) Pressure and volume are inversely proportional
C) Temperature remains constant
D) Gas solubility changes
Answer: B
Explanation: As thoracic volume increases, intrapulmonary pressure falls below atmospheric pressure,
causing air to move inward.
Question 10. **Which muscle group is recruited during forced expiration?**
A) External intercostals
B) Diaphragm
C) Internal intercostals and abdominal muscles
D) Scalenes
Answer: C
, ITEC Respiratory System Ultimate Exam
Explanation: Forced expiration requires active contraction of internal intercostals and abdominal
muscles to decrease thoracic volume rapidly.
Question 11. **The primary site of external respiration (gas exchange) is:**
A) Bronchi
B) Alveolar ducts
C) Alveoli
D) Trachea
Answer: C
Explanation: Alveoli have thin walls and a rich capillary network, allowing O₂ and CO₂ diffusion between
air and blood.
Question 12. **In internal respiration, oxygen diffuses from:**
A) Alveolar air to pulmonary capillary blood
B) Systemic capillary blood to tissue cells
C) Venous blood to arterial blood
D) Tissue cells to pulmonary capillaries
Answer: B
Explanation: Internal respiration refers to O₂ moving from systemic capillaries into tissue cells, and CO₂
moving in the opposite direction.
Question 13. **Which form of hemoglobin carries the majority of carbon dioxide in the blood?**
A) Oxyhemoglobin
B) Carbaminohemoglobin
C) Methemoglobin
D) Fetal hemoglobin
Answer: B
Explanation: About 20–25% of CO₂ is transported bound to the amino groups of hemoglobin as
carbaminohemoglobin.
