GENERAL HISTOLOGY

Detailed explanation-1: -Epithelial layers contain no blood vessels (avascular), so they must receive nourishment via diffusion of substances from the underlying connective tissue, through the basement membrane.

Detailed explanation-2: -Epithelial tissues do not contain blood vessels and as such are avascular. Connective tissues are usually highly vascular and so the nearby connective tissue provides essential nutrients (from the blood) to the epithelial tissue.

Detailed explanation-3: -Answer and Explanation: The epithelium is connected to the underlying connective tissues by the basement membrane. This is comprised of two layers which are the basal lamina and the reticular connective tissue.

Detailed explanation-4: -Epithelial and connective tissue are generally avascular, which means they lack a blood supply. While, Muscle and nervous tissue are vascular tissues, which means they have a strong blood supply.

Detailed explanation-5: -Epithelial tissues are nearly completely avascular. For instance, no blood vessels cross the basement membrane to enter the tissue, and nutrients must come by diffusion or absorption from underlying tissues or the surface. Many epithelial tissues are capable of rapidly replacing damaged and dead cells.