Question

The lining of blood vessels, lung alveoli and kidney tubules are all made up of ______ tissue.
A. Endothelial
B. Connective
C. Epithelial
D. All of the above

Answer 1

Hint: Tissues are a group of cells that are similar in structure, origin and function. The word tissue was given by Bichat. The animal body has four types of fundamental tissue- epithelial, muscular, connective and nervous.

Complete answer:
> Connective tissues are special tissues that perform the function of linking and supporting other tissues or organs of the body. This tissue arises from the mesoderm of the embryo. These are the most abundant types of animal tissue. It consists of variously shaped cells lying wide apart in a large amount of non-living intracellular or extracellular material called the matrix.
> An epithelium tissue covers the external surface of the body and viscera i.e. the internal organs and is composed of one or more layers of cells. It also lines the cavities in the body. Epithelial tissue is classified on the basis of cell layers and shape of cells. These are mainly of two types- simple and compound epithelial tissue. Simple epithelia is further classified as squamous, cuboidal, ciliated and columnar epithelium on the basis of the form and structure of their cells.
> The lining of blood vessels and alveoli are lined by squamous epithelium while the kidney tubules are lined by cuboidal epithelium tissue.
> Simple squamous epithelium consists of thin, flat, disc-like cells that are closely fitted like tiles in a floor and thus are also called pavement epithelium. The simple squamous epithelium that lines the blood vessels and the coelom are called endothelium and mesothelium respectively. These cells outlining these tissues are wavy. These are also called tessellated epithelium.

So the correct answer is D. Epithelial tissue.

Note: The main function of the epithelium tissue is to provide protection, and help in excretion, gas exchange and secretion of coelomic fluid. The cells of this tissue are subjected to wear, tear and injury so they keep on dividing for producing new cells.