The walls of capillaries are composed of endothelium,which is:

This epithelium is made of a single thin layer of flattened cells and is involved in functions like forming a diffusion boundary. It is found in:

$A$: Gap junctions connect the cytoplasm of adjoining cells.
$R$: Gap junctions facilitate the cells to communicate with each other.

Cells of the epithelial tissue rest on a basement membrane which is made up of

The cells of the coelomic epithelium are made up of which type of tissue?

Junction which facilitates the exchange of small and sometimes big molecules is $:-$