The alveolus is a small air sac in the lungs where gas exchange takes place. It is surrounded by a network of capillaries and is lined with a layer of epithelial cells.
Labels of the alveolus: 1. Type I alveolar cell: Thin, flat cells that make up the majority of the alveolar wall and are responsible for gas exchange. 2. Type II alveolar cell: Cuboidal cells that secrete surfactant, a substance that helps reduce surface tension in the alveoli and prevents them from collapsing. 3. Capillaries: Tiny blood vessels that surround the alveoli and allow for the exchange of oxygen and carbon dioxide between the blood and the air in the alveoli. 4. Alveolar macrophages: Immune cells that help remove debris and pathogens from the alveoli to maintain lung health. 5. Basement membrane: A thin layer of connective tissue that provides support and structure to the alveolar wall. 6. Interstitial space: The space between the alveolar wall and the capillaries where gas exchange takes place.
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Google Gemini AI
Jul 18
Structure of the Alveolus:
1. Alveolar Lumen: - Central air-filled space. - Exchanged gases (O2 and CO2) diffuse across it.
2. Alveolar Epithelium: - Single layer of thin, flat cells. - Type I Pneumocytes (95%): Allow for gas exchange. - Type II Pneumocytes (5%): Secrete surfactant to reduce surface tension.
3. Alveolar Wall: - Surrounds the alveolar lumen. - Consists of: - Basement Membrane: Supports the epithelium. - Interstitial Space: Contains capillaries, macrophages, and fibroblasts. - Elastic Fibers: Provide structural support and elasticity. - Alveolar Pore: Small openings that connect adjacent alveoli.
4. Capillaries: - Tiny blood vessels that run along the alveolar wall. - Located close to the epithelium, facilitating gas exchange.
5. Macrophages: - Free cells within the interstitial space. - Phagocytize pathogens and debris from the alveoli.
6. Pore of Kohn: - Small openings that connect adjacent alveoli. - Allow for gas distribution within the lung.
7. Interlobular Septum: - Divides the lung into lobules. - Contains blood vessels, airways, and connective tissue.