Substantia propria

Substantia Propria is a term used in anatomy and histology to describe the main, functional part of an organ or tissue. The term is derived from Latin, where "substantia" means "substance" or "material", and "propria" means "own" or "proper". This term is used to differentiate the main functional part of an organ from its connective tissue framework, or stroma.

Anatomy and Histology[edit | edit source]

In anatomy and histology, the term "substantia propria" is used to describe the main, functional part of an organ or tissue. This is in contrast to the stroma, which is the connective tissue framework that supports the organ or tissue. The substantia propria contains the cells that carry out the main functions of the organ or tissue.

For example, in the cornea, the substantia propria is the thick, central layer that makes up the majority of the cornea's thickness. It is composed mainly of collagen fibers and keratocytes, which are specialized cells that produce and maintain the collagen matrix.

In the mucous membrane, the substantia propria is the layer of loose connective tissue that underlies the epithelium. It contains blood vessels, nerves, and immune cells, and supports the epithelium in its functions of protection, secretion, and absorption.

Clinical Significance[edit | edit source]

Changes in the substantia propria can be indicative of disease. For example, in keratoconus, a degenerative disorder of the eye, the collagen fibers in the corneal substantia propria become thin and irregular, leading to a conical shape of the cornea and impaired vision.

In the mucous membranes, inflammation or infection can lead to changes in the substantia propria, such as increased blood vessel dilation and immune cell infiltration. These changes can be observed under the microscope in histological samples, and can help in the diagnosis of diseases such as inflammatory bowel disease or gastritis.