Respiratory System

What is ventilation in the context of the respiratory system?

Movement of air into and out of the lungs (breathing).

What takes place during external respiration?

Gas exchange between alveoli and pulmonary blood where O₂ enters the blood and CO₂ leaves.

What occurs during internal respiration?

Gas exchange between systemic blood and body tissues where O₂ is delivered to tissues and CO₂ is transported back to the blood.

What structures are involved in the respiratory system for air conduction?

Nose, pharynx, larynx, trachea, bronchi/branches.

What is the primary function of the alveoli?

Site of gas exchange.

What differentiates the respiratory zone from the conducting zone?

Respiratory zone includes structures for gas exchange, while the conducting zone comprises passages that only conduct air.

What is anatomical dead space?

Air in conducting pathways (~150 mL) that is not involved in gas exchange.

What is alveolar dead space?

Alveoli that do not exchange gases due to collapse or blockage.

How do cilia contribute to respiratory health?

Cilia move mucus and trapped particles toward the throat for swallowing, keeping lungs sterile.

Why is it important to warm inspired air?

Warmer air increases diffusion efficiency and protects the delicate alveoli.

What roles do the sinuses play in the respiratory system?

They lighten the skull, produce mucus, and warm/moisten air.

What does the larynx do?

Routes food and air and houses vocal cords.

What is the function of the pharyngotympanic tube?

Connects the middle ear to the nasopharynx and equalizes pressure between ear and throat.

What is the purpose of the epiglottis?

Covers the larynx during swallowing to prevent food from entering the airway.

What are the true vocal cords and their function?

True vocal cords (vocal folds) produce sound.

What influences the pitch of the voice?

The length and tension of the vocal cords.

How does the trachea's structure contribute to its function?

Reinforced with C-shaped hyaline cartilage rings and lined with cilia to maintain open airways.

How is coughing related to the trachea?

Coughing is triggered by irritants when the glottis closes and pressure builds, forcing air out.

What is the Heimlich maneuver?

A method of abdominal thrusts to expel a foreign object obstructing the trachea.

Where does gas exchange primarily occur?

In the alveoli of the respiratory zone.

What constitutes the respiratory membrane?

A thin barrier consisting of alveolar epithelium, fused basement membrane, and capillary endothelium.

What is the role of surfactant in the lungs?

Reduces surface tension to prevent alveolar collapse, especially during exhalation.

What happens when intrapleural pressure is lost?

The vacuum is lost, leading to lung collapse.

What are obstructive diseases characterized by?

Airflow limitation with increased total lung capacity (TLC), functional residual capacity (FRC), and residual volume (RV).

What is the significance of partial pressure in respiration?

It determines the pressure each gas contributes to the total mixture, driving gas diffusion.

How do changes in pH and temperature affect oxygen affinity for hemoglobin?

A decrease in pH or an increase in temperature reduces O2 affinity, enhancing O2 delivery to tissues.

What role does erythropoietin play in high altitude conditions?

It stimulates the production of red blood cells, increasing blood viscosity due to low O2 levels.

What is the primary stimulant for respiration?

Rising CO₂ levels, which increase H+ concentration in the brain.