Question

1) Why is the zonula adherans only found in epithelia and not other tissues? Or looking at it another way, why are the other cell junctions found in other tissues in addition to epithelia?

2) Why would glycocalyx be associated with microvilli?

3) What is the terminal bar and why can we see it using a light microscope?

Answer 1

1.The adherens junction which is also known as zonula adherens which are a type of protein complexes. These are mainly observed in the interjunction between two cells and tissues like epithelial and endothelial. In the epithelial tissues one of the most commonly found part is the cell junctions, these tissues are combined with molecules and cellular matrix which combines to the cell and to hold them intact position.

2. The glycocalyx are associated with microvilli , as these glycocalyx are mostly present in the digestive tract ( microvilli within the small intestine). The main function is the absorption and adsorption. It also includes the enzyme secretion and the helps in the final steps of digestion of complex sugars and proteins.

3. The terminal bar is found as a spot at the apical surface in the cell. It mainly occurs in light microscopy. This cannot be determined by any other. Whereas in electron microscopy , they can be found and can be closely assessed to these type of structures.