Question

Inner line of vagina is composed of
A. Stratified ciliated columnar epithelium
B. Simple squamous epithelium
C. Simple columnar epithelium
D. Stratified squamous epithelium

Answer 1

Hint: The vagina can be thought of as a fibro-muscular tube when it is relaxed. It lies within the female pelvis. The inner lining of vagina is the vaginal epithelium. The walls of the vagina are composed of three different layers; mucosa, muscularis and adventitia. There are cells that are specific for inner vaginal lining that lie in deeper layers of the submucosa layer.

Complete answer:
> Stratified ciliated columnar epithelium- Here the cells are columnar and ciliated as the name suggests. This is mainly responsible for the lining of epididymis, vas deferens and respiratory passages. Hence, this is not the suitable option.

> Simple squamous epithelium- It is only one layer of cells that are flat and are in contact with the basal lamina. This epithelium serves as an advantage to the small molecules to pass through the membrane as it is permeable. It can be mainly found in areas including skin, alveolar and peritoneal cavity and capillary walls. So, it is not found in the inner line of vagina.

> Simple columnar epithelial- Here the columnar cells are attached to the basement membrane and they have an oval shaped nuclei. It lines many organs of the digestive system.

> Stratified squamous epithelium- The inner lining of the vagina is made up of this stratified squamous epithelium. One layer is attached to the basement membrane and the others are attached to each other so that structural integrity can be properly maintained.

Hence, the correct answer is option (D).

Note: The epithelial cells are spread throughout our body. They are the protective coating for body surfaces, body cavities and hollow organs. They perform some very vital functions like absorption, secretion, diffusion and many others. Their structure is such that they are very tightly packed with very less intercellular matrix. All these cells are attached to a layer or membrane called a basement membrane which consists of carbohydrates and proteins which they epithelial cells secrete.