Structural Support: The
extracellular matrix and connective tissue fibers provide a scaffold that maintains the shape and integrity of the organ.
Nutrient and Waste Transport: Blood vessels within the stroma facilitate the delivery of oxygen and nutrients to the parenchymal cells and the removal of metabolic waste.
Immune Response: The stroma contains various
immune cells that help defend against pathogens and mediate inflammatory responses.
Signaling and Communication: The ECM and stromal cells secrete signaling molecules such as
growth factors and cytokines that regulate cell behavior and tissue homeostasis.
Fibroblasts: These are the most common cells in connective tissue and are responsible for synthesizing the ECM and collagen.
Extracellular Matrix (ECM): Composed of proteins like collagen and elastin, as well as glycoproteins and proteoglycans, the ECM provides structural and biochemical support to surrounding cells.
Blood Vessels: Capillaries, arterioles, and venules within the stroma ensure a steady supply of nutrients and oxygen.
Immune Cells: Macrophages, mast cells, and lymphocytes are present to mediate immune responses and tissue repair.
Light Microscopy: Stained tissue sections are observed under a microscope to identify the cellular and extracellular components.
Electron Microscopy: Provides high-resolution images of the ultrastructure of stromal components, such as the arrangement of collagen fibers.
Immunohistochemistry (IHC): Uses antibodies to detect specific proteins, allowing for the localization of different cell types and ECM components.
Histochemical Staining: Techniques like Masson's Trichrome and Van Gieson's stain are used to differentiate between various tissue elements such as collagen and muscle fibers.
Cancer: The
tumor microenvironment includes stromal cells that can influence tumor growth, metastasis, and response to therapy.
Fibrosis: Excessive deposition of ECM components by fibroblasts can lead to fibrotic diseases affecting organs like the liver, lungs, and kidneys.
Wound Healing: Stromal cells play a key role in tissue repair and regeneration, making them targets for therapeutic interventions in chronic wounds and injuries.
Inflammatory Diseases: The stroma's immune components are involved in conditions such as rheumatoid arthritis and inflammatory bowel disease.
