Lungs, Gas Exchange and Ventilation

Lesson Objectives

Content Objective: How structure of the lungs and alveoli aid in gas exchange and how ventilation maintains a diffusion gradient so that gas exchange can occur passively.

Language Objective: Explain how structure of the lungs and alveoli aid in gas exchange and how ventilation maintains a diffusion gradient so that gas exchange can occur passively.

Book Reference: pg 291 - 297

Syllabus Statements:

Ventilation maintains concentration gradients of oxygen and carbon dioxide between air and alveolous and blood flowing in adjacent capillaries
Air is carried to the lungs in the trachea and bronchi and then to the alveoli in bronchioles
Muscle contraction cause the pressure changes inside the thorax that force air in and out of the lungs to ventilate them
Different muscles are required for inspiration and expiration because muscles only do work when they contract
External and internal intercostal muscles, and diaphragm and abdominal muscles as examples of antagonistic muscle action
Type I pneumocytes are extremely thin alveolar cells that are adapted to carry out gas exchange
Type II pneumocytes secrete a solution containing surfactant that creates a moist surface inside the alveoli to prevent the sides of the alveolus adhering to each other by reducing surface tension
Causes and consequences of lung cancer
Causes and consequences of emphysema
Skill: Identification of pneumocytes, capillary endothelium cells and blood cells in light micrographs and electron micrographs of lung tissue.