Occurrence and importance of glomus organs (Hoyer-Grosser’s organs) in the skin of the equine and bovine mammary gland.

This research article examines the occurrence and importance of glomus organs (Hoyer-Grosser’s organs) in the skin of the mammary gland in equines and bovines. The study reports these specialized vascular structures in all investigated skin areas and discusses aspects like their functional interpretation, potential involvement of lymphatics, and their relevance.

Overview of Glomus Organs

• The study centers on glomus organs (Hoyer-Grosser’s organs), which were frequently detected in the corium (also known as the “dermis”, the thick layer of skin beneath the epidermis) and subcutis (a layer of tissue beneath the skin) of the skin of the mammary gland in equines and bovines.
• Glomus organs are arteriovenous anastomoses, structures that facilitate direct connections between the arterial and venous blood supply, without passing through capillaries.

Location of the Glomus Organs

• These organs were often found in the border zone between two layers of the skin: the stratum profundum (the deeper layer of the dermis) and the stratum superficiale corii (the upper layer of the dermis).
• Despite varying sizes and shapes, these organs were found in all the examined skin areas.

Composition and Structure of the Glomus Organs

• The glomus organs have several common histological features. These include an arteriole (a small branch of an artery that leads into capillaries) entering the connective tissue capsule of the glomus and dividing into strongly convoluted arteriovenous channels.
• The arteriovenous channels eventually merge to form a venule (a very small vein, especially one collecting blood from capillaries).
• All these vascular components are enveloped by a connective tissue capsule, forming an organ-like structure.

Discussed Aspects of the Glomus Organs

• The research further addresses the occurrence, function, and significance of these glomus organs.
• Other aspects considered include the size variance of the glomus organs and a hypothesized involvement of the lymphatics, which are essential for maintaining fluid balance and serving a crucial role in the body’s immune system.