Pseudostratified columnar epithelium is best described as which statement?

Pseudostratified columnar epithelium is best described as which statement?

• A. Appears to be multiple layers but is a single layer of cells
• B. Contains many layers of different cell sizes
• C. Is composed of short cells only
• D. Is keratinized

Answer: (A)

Pseudostratified columnar epithelium appears to have multiple layers because the nuclei are at different heights, but every cell is anchored to the basement membrane, so it is technically a single, simple layer. This illusion of layering comes from the varying cell heights, not from true layered organization. The tissue is typically tall, with ciliated cells and goblet cells that secrete mucus, which helps move mucus along the surface in the respiratory tract. That’s why the description statement is the best fit: it captures the key idea that the tissue looks multilayered but is actually a single layer of cells attached to the base. The other possibilities don’t fit because this tissue is not made up of several true layers of different cell sizes, it isn’t composed only of short cells, and it is not keratinized (which would be a feature of some skin-type epithelium, not this respiratory-type tissue).

Pseudostratified columnar epithelium appears to have multiple layers because the nuclei are at different heights, but every cell is anchored to the basement membrane, so it is technically a single, simple layer. This illusion of layering comes from the varying cell heights, not from true layered organization. The tissue is typically tall, with ciliated cells and goblet cells that secrete mucus, which helps move mucus along the surface in the respiratory tract.

That’s why the description statement is the best fit: it captures the key idea that the tissue looks multilayered but is actually a single layer of cells attached to the base. The other possibilities don’t fit because this tissue is not made up of several true layers of different cell sizes, it isn’t composed only of short cells, and it is not keratinized (which would be a feature of some skin-type epithelium, not this respiratory-type tissue).