Which structures are highlighted?
- pseudostratified columnar epithelium 2. goblet cells 3. cilia 4. microvilli
The Correct Answer and Explanation is :
The structures highlighted in your query include:
- Pseudostratified columnar epithelium
- Goblet cells
- Cilia
- Microvilli
Explanation:
Pseudostratified Columnar Epithelium: This type of epithelial tissue appears to be stratified because the nuclei are at different levels, giving the impression of multiple layers. However, it is actually a single layer of cells, where all cells are attached to the basement membrane. This type of epithelium is commonly found in the respiratory tract, particularly in the trachea and bronchi, where it plays a crucial role in the movement of mucus.
Goblet Cells: These are specialized epithelial cells located within the pseudostratified columnar epithelium. They are responsible for producing and secreting mucus, which serves to trap dust, pathogens, and other particles, helping to keep the respiratory tract clear and moist. The mucus also aids in the movement of cilia by providing a medium for their action.
Cilia: These are hair-like structures that extend from the surface of epithelial cells, particularly in the respiratory tract. Cilia beat in a coordinated manner to move mucus and trapped particles out of the airways, a process essential for maintaining respiratory health. This action is often referred to as the “mucociliary escalator,” which helps to clear debris and pathogens from the lungs.
Microvilli: These are smaller, finger-like projections found on the surface of epithelial cells, increasing the surface area for absorption and secretion. While they are not typically abundant in pseudostratified columnar epithelium, they are crucial in other types of epithelial tissues, such as the intestines, where they enhance nutrient absorption.
Together, these structures are vital for the protective and functional roles of epithelial tissues, especially in the respiratory system, where they collaborate to maintain a clear airway and facilitate efficient gas exchange.