Label the structures on this slide of simple columnar epithelium. Basement membrane Lamina propria Goblet cell Nucleus of columnar cell Lumen Microvilli (brush border) Columnar epithelial cell Lumen
The Correct Answer and Explanation is:
Here are the correct labels for the structures on the slide of simple columnar epithelium, from top to bottom:
- Microvilli (brush border)
- Goblet cell
- Columnar epithelial cell
- Nucleus of columnar cell
- Basement membrane
- Lamina propria
- Lumen
Explanation
This image displays a micrograph of simple columnar epithelium, a tissue type characterized by a single layer of tall, column-shaped cells. This tissue is commonly found lining organs of the digestive tract, such as the small intestine.
The topmost pointer indicates the microvilli, which are microscopic projections of the cell membrane on the apical (top) surface of the epithelial cells. Collectively, they form a brush border, which appears as a fuzzy line under a light microscope. Their primary function is to dramatically increase the surface area available for absorption.
The second pointer identifies a goblet cell. These specialized cells are interspersed among the columnar cells and are responsible for secreting mucus. The mucus lubricates the lining of the intestine and protects it from digestive enzymes. Goblet cells appear pale and swollen because the mucus within them does not stain well with standard histological dyes.
The third pointer indicates an entire columnar epithelial cell, the main cell type of this tissue. These cells are taller than they are wide and are involved in secretion and absorption.
The fourth pointer is directed at the nucleus of a columnar cell. In this type of epithelium, the nuclei are typically elongated and located in the basal half of the cell, often aligned in a row.
Below the layer of cells, the fifth pointer shows the basement membrane. This is a thin, non-cellular layer of proteins and carbohydrates that anchors the epithelial cells to the underlying connective tissue.
The sixth pointer indicates the lamina propria. This is a layer of loose connective tissue situated directly beneath the basement membrane. It provides structural support and vascular supply (blood vessels) to the avascular epithelium.
Finally, the bottom pointer, already labeled, points to the lumen. This is the open space or cavity of the organ that the epithelium lines, in this case, likely the inside of the intestine.
