Respiratory System: Gas Exchange in Alveoli

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What are the two main parts of the air passages in the respiratory system?

Conducting airway and respiratory tissues

Which cells line the wall of conducting airways and form a layer called mucociliary blanket?

Mucus-secreting gland cells

What is the function of ciliated cells in the conducting airways?

Clear the lower airways and alveoli

What happens to the motility of ciliated cells in the airways due to smoking?

Paralyzed Signup and view all the answers

What structures make up the conducting airways in the respiratory system?

Nasal passage, mouth, pharynx, larynx, trachea, bronchi, bronchioles Signup and view all the answers

What is the key function of the respiratory tissues in the lungs?

Gas exchange Signup and view all the answers

What is the function of Type I epithelial cells in the alveolar structure?

Gas exchange takes place Signup and view all the answers

What is the role of Type II cells in the alveoli?

They produce surfactant Signup and view all the answers

Explain the concept of surface tension as it relates to the alveoli.

It is the interface between the liquid film lining the alveoli and alveolar air Signup and view all the answers

Why do alveoli with the smallest radii not empty into larger alveoli?

Because of surfactant Signup and view all the answers

How does surfactant work to decrease surface tension in the alveoli?

By attaching its head to liquid molecules and its tail to gas molecules Signup and view all the answers

What are some functions of surfactant in the alveoli?

Prevent alveolar collapse, provide stability, distribute ventilation, keep alveoli dry, prevent pulmonary edema Signup and view all the answers

What is the function of serous glands in the respiratory system?

To secrete a watery fluid containing antibacterial enzymes for moist and protection Signup and view all the answers

How does an increase in respiratory rate and fever affect the moisture in the lungs?

It increases water vapor in the lungs, causing withdrawal of moisture from the mucosal surface, thickening secretions, and diminishing free cilia movement. Signup and view all the answers

What is the main function of the larynx in the respiratory system?

The larynx promotes speech, protects the lungs during swallowing, and directs liquids and food into the esophagus. Signup and view all the answers

How are the walls of the trachea supported to prevent collapse?

The trachea is supported by C-shaped rings of hyaline cartilage. Signup and view all the answers

Why is cartilage absent in the walls of bronchioles?

Bronchioles do not have cartilage to allow flexibility and regulation of airflow through smooth muscle and elastic fibers. Signup and view all the answers

What are the functions of the lungs in the respiratory system?

The functions of the lungs include gas exchange, conversion of angiotensin I to angiotensin II, heparin production, and inactivation of vasoactive substances. Signup and view all the answers

What two factors interfere with the matching of ventilation and perfusion in the lungs?

Dead air space and shunt Signup and view all the answers

What is alveolar dead space?

Alveoli that are ventilated but not perfused Signup and view all the answers

Why does CO2 diffuse 20 times more rapidly than O2 in the respiratory membrane?

Due to its great solubility Signup and view all the answers

What are the two forms in which oxygen is transported in the blood?

In chemical combination with hemoglobin (98-99%) Signup and view all the answers

What is the normal range for partial pressure of CO2 (PCO2) in arterial blood?

35 to 45 mmHg Signup and view all the answers

What is the main purpose of matching ventilation and perfusion in the lungs?

To ensure equal amounts of gas and blood enter the respiratory portion of the lungs Signup and view all the answers

What is lung compliance?

Lung compliance refers to the ease with which the lungs can be inflated. Signup and view all the answers

Define tidal volume (TV).

Tidal volume is the amount of air that moves into and out of the lung during a normal breath. Signup and view all the answers

What is the formula for Vital Capacity (VC)?

Vital Capacity (VC) = Inspiratory Reserve Volume (IRV) + Tidal Volume (TV) + Expiratory Reserve Volume (ERV). Signup and view all the answers

Explain the term Alveolar ventilation.

Alveolar ventilation refers to ventilation in the gas exchange portion of the lungs. Signup and view all the answers

What is the primary function of pulmonary circulation?

The primary function of pulmonary circulation is to provide blood flow to the gas exchange portion of the lungs. Signup and view all the answers

What happens in the case of hypoxia?

Hypoxia leads to marked vasoconstriction in the blood vessels when alveolar oxygen levels drop below 60 mmHg. Signup and view all the answers

Describe Diffusion in the context of gas exchange.

Diffusion refers to the movement of gases in the alveoli and across the alveolar-capillary membrane. Signup and view all the answers

What are the three processes involved in pulmonary gas exchange?

The three processes are ventilation, perfusion, and diffusion. Signup and view all the answers

How does lung compliance change in pulmonary fibrosis?

In pulmonary fibrosis, the lung becomes stiff and noncompliant as elastin fibers are replaced by scar tissue. Signup and view all the answers

Explain the concept of Functional Residual Capacity (FRC).

Functional Residual Capacity (FRC) is the sum of Residual Volume (RV) and Expiratory Reserve Volume (ERV) in the lungs. Signup and view all the answers