Stroma (tissue)

Stroma
Prostate under a microscope This image shows the microscopic glands of the prostate
Identifiers
Code	TH H2.00.00.0.00003
Anatomical terminology []

Stroma (from Greek στρῶμα, meaning “layer, bed, bed covering”) is the part of a tissue or organ that has a connective and structural role. It consists of all the parts which do not conduct the specific functions of the organ, for example, connective tissue, blood vessels, nerves, ducts, etc. The other part is the parenchyma, which is the cells that perform the function of the tissue or organ. There are multiple ways of classifying tissues: one way of classifying tissues is based on their functions and another is based on their cellular components. Stromal tissue falls into the class that functions in contributing to the body’s support and movement. The cells that stroma tissues are composed of serve as a matrix in which the other cells are embedded. Stroma is made of various types of stromal cells.

Examples of stroma include:

Stromal connective tissues are found in the stroma; this tissue belongs to the group connective tissue proper. The function of connective tissue proper is to secure the parenchymal tissue, including blood vessels and nerves of the stroma, and to construct organs and spread mechanical tension to reduce localised stress. Stromal tissue is primarily made of extracellular matrix containing connective tissue cells. Extracellular matrix is primarily composed of ground substance - a porous, hydrated gel, made mainly from proteoglycan aggregates - and connective tissue fibers. There are three types of fibers commonly found within the stroma: collagen type I, elastic, and reticular (collagen type III) fibres.