Respiratory Lab Worksheet Label the photomicrogram of the trachea. Connect 0.23 points Print References Reset Zoom Saved Help Save & Exit Submit Cartilage Epithelium Submucosa Perichondrium Lamina propria
The Correct Answer and Explanation is:
To accurately label a photomicrograph of the trachea, you must identify and distinguish between the major histological layers. These typically include:
- Epithelium – the innermost lining.
- Lamina propria – connective tissue under the epithelium.
- Submucosa – loose connective tissue with glands and blood vessels.
- Cartilage – hyaline cartilage providing structural support.
- Perichondrium – the connective tissue sheath surrounding the cartilage.
Correct Labeling of Tracheal Photomicrograph:
From lumen outward (innermost to outermost):
- Epithelium
- Lamina propria
- Submucosa
- Cartilage (Hyaline cartilage)
- Perichondrium
Explanation
The trachea is a vital respiratory structure composed of several histological layers, each serving specific functions in airway conduction and protection.
The epithelium lining the trachea is pseudostratified ciliated columnar epithelium with goblet cells. This epithelial layer plays a key role in the mucociliary escalator system: the cilia beat rhythmically to move mucus and trapped debris upward toward the pharynx for removal, thus protecting the lower respiratory tract.
Beneath the epithelium lies the lamina propria, a thin layer of loose connective tissue that contains blood vessels, nerves, and immune cells. This layer supports the epithelium structurally and immunologically.
Following that is the submucosa, which contains mucous and seromucous glands, lymphatic tissue, and larger blood vessels. These glands secrete mucus into ducts that open into the tracheal lumen, enhancing the airway’s protective mucus layer.
The cartilage layer is composed of C-shaped rings of hyaline cartilage, which help maintain the trachea’s open lumen. These rings prevent airway collapse during breathing and give the trachea its characteristic rigidity and flexibility.
Surrounding the cartilage is the perichondrium, a dense irregular connective tissue layer rich in fibroblasts and chondroblasts. It plays a crucial role in cartilage growth and repair, supplying nutrients to the avascular cartilage.
Understanding the microscopic anatomy of the trachea is essential for recognizing how structure supports function in the respiratory system—ensuring air conduction, filtering, humidifying, and protecting against pathogens.
