Respiratory Organs and Functions
What organ contains the vocal folds and is commonly called the voice box?
The larynx.
What is the pharynx commonly called?
The throat.
What flap helps protect the airway during swallowing?
The epiglottis.
What are the two main branches of the trachea called?
Answer: The right and left primary bronchi.
What tiny air sacs are the main sites of gas exchange?
Answer: Alveoli.
What tube connects the larynx to the primary bronchi?
The trachea.
What three things does the nasal cavity do to incoming air?
Filters, warms, and humidifies it.
Which laryngeal structures vibrate to produce sound?
The true vocal folds.
How do secondary and tertiary bronchi differ in the areas they supply?
Answer: Secondary bronchi supply lung lobes; tertiary bronchi supply bronchopulmonary segments.
Which alveolar cells form most of the thin gas-exchange surface?
Answer: Type I alveolar cells.
Question: Put these structures in airflow order: trachea, nasal cavity, bronchi, larynx, pharynx.
Nasal cavity → pharynx → larynx → trachea → bronchi.
What are the three regions of the pharynx, from superior to inferior?
Nasopharynx → oropharynx → laryngopharynx.
What supports the trachea and helps prevent its collapse?
Answer: C-shaped rings of hyaline cartilage.
What small airways lack cartilage and use smooth muscle to adjust their diameter?
Answer: Bronchioles.
Which cells produce surfactant, and what does it do?
Answer: Type II alveolar cells. Surfactant lowers surface tension, helping prevent alveolar collapse and making inflation easier.
Besides gas exchange, name three functions of the respiratory system.
Answer: Regulating blood pH, producing sound, and providing the sense of smell. It also helps protect against inhaled pathogens and particles.
How do the nasal conchae help condition inhaled air?
They increase surface area and create turbulence, increasing contact with the mucosa so air can be warmed, humidified, and filtered.
How do goblet cells and cilia work together in the trachea?
Answer: Goblet cells produce mucus that traps particles. Cilia move the mucus toward the pharynx for removal.
What is the difference between the conducting zone and respiratory zone?
Answer: The conducting zone moves and conditions air. The respiratory zone contains alveoli and allows gas exchange.
What forms the thin respiratory membrane between alveolar air and blood?
Answer: The alveolar epithelium, the thin basement membrane layer between them, and the capillary endothelium.
Trace airflow from the trachea to the alveoli.
Answer: Trachea → primary bronchi → secondary bronchi → tertiary bronchi → bronchioles → terminal bronchioles → respiratory bronchioles → alveolar ducts → alveolar sacs and alveoli.
Where are the paranasal sinuses, and what are their functions?
Answer: They are air-filled spaces in bones surrounding the nasal cavity. They produce mucus, lighten the skull, and contribute to voice resonance.
why are the tracheal cartilage rings open posteriorly, and what spans that opening?
Answer: The opening allows the esophagus to expand during swallowing. The trachealis muscle spans it and can adjust tracheal diameter.
Where does the conducting zone end, and what structures make up the respiratory zone?
Answer: The conducting zone ends at the terminal bronchioles. The respiratory zone includes respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
Why can insufficient surfactant cause breathing problems in premature infants?
Answer: High surface tension promotes alveolar collapse and decreases lung compliance, increasing the effort needed to inflate the lungs.