Tag Archives: alveoli

Alveolar Units
4
Feb

Overview

Alveoli are microscopic air sacs where oxygen and carbon dioxide exchange occurs across thin alveolar capillary membranes. Surfactant reduces surface tension and prevents alveolar collapse while capillary perfusion enables gas transport. Alveolar integrity is essential for efficient respiration.

Alveolar Structure

Type I pneumocytes provide a thin barrier for gas diffusion while type II pneumocytes produce surfactant and contribute to repair. Alveolar macrophages clear debris and pathogens to maintain sterility. Interstitial tissue supports capillaries and gas exchange.

Gas Exchange Dynamics

Diffusion across the alveolar capillary membrane depends on surface area thickness and partial pressure gradients. Ventilation perfusion matching optimizes oxygen uptake and carbon dioxide removal. Disruption by edema inflammation or fibrosis impairs gas exchange.

Clinical Relevance

Alveolar disease includes pneumonia pulmonary edema and acute respiratory distress syndrome. Imaging with chest radiography and CT identifies consolidation interstitial changes and edema. Supportive care and targeted therapy address underlying causes.

Respiratory System
4
Feb

Overview

The respiratory system enables gas exchange between the environment and the bloodstream. It includes the nose pharynx larynx trachea bronchi and lungs with alveolar units. Ventilation perfusion matching is critical for oxygenation and carbon dioxide removal.

Upper Airway

The nose and pharynx filter warm and humidify inspired air. The larynx protects the airway and facilitates phonation. Upper airway patency affects breathing and sleep related disorders.

Lower Airway and Lungs

The trachea divides into bronchi and bronchioles terminating in alveoli for gas exchange. Pulmonary circulation delivers blood for oxygenation and removes carbon dioxide. Surfactant and alveolar architecture maintain lung compliance and surface area.

Clinical Relevance

Respiratory diseases include pneumonia COPD asthma and pulmonary embolism. Imaging such as chest radiography CT and ultrasound aid diagnosis and guide therapy. Pulmonary function testing complements imaging for functional assessment.