Gas Exchange and the Respiratory System

These flashcards cover key vocabulary and concepts related to gas exchange and the respiratory system as outlined in the lecture.

Alveoli

Cup shaped pouches in the lungs, approximately 300 million in number, where gas exchange occurs.

Type I Pneumocytes

Simple squamous epithelial cells in the alveoli that are the primary site of gas exchange.

Type II Pneumocytes

Simple cuboidal cells in the alveoli that secrete alveolar fluid and surfactant.

Surfactant

A substance secreted by Type II pneumocytes that reduces surface tension in the alveoli, preventing collapse.

Respiratory Membrane

The barrier between the alveoli and capillaries, consisting of alveolar epithelium, fused basement membrane, and capillary endothelium.

Partial Pressure

The pressure exerted by a single gas in a mixture of gases, dictating the movement of gases across membranes.

External Respiration

Gas exchange that occurs between the alveoli and blood in the lungs.

Internal Respiration

Gas exchange that occurs between blood in the capillaries and body tissues.

Gas Transport

The process by which oxygen and carbon dioxide are carried in the blood.

Pulmonary Ventilation

The act of breathing, which involves inhalation and exhalation to replenish oxygen and remove carbon dioxide.