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Thermal Physiology and Thermoregulation
Published in James Stewart Campbell, M. Nathaniel Mead, Human Medical Thermography, 2023
James Stewart Campbell, M. Nathaniel Mead
Glabrous skin of the palms and soles contains a large number of glomus bodies, also known as arteriovenous anastomoses or AVAs.39 Although only about 0.5 mm (0.02 in.) in diameter, glomus AVAs can produce substantial changes in blood flow to the skin. The highest concentration of AVAs is found in the nail beds of the fingers and toes (600 AVAs/cm2) and in the skin of the palms and soles (100 AVAs/cm2).40 Glomus bodies are also found scattered over many areas of the non-glabrous skin surface. Glomus AVAs are within a firm capsule. An afferent arteriole enters the glomus body, becoming tortuous with a small lumen and a thick, muscular wall. Richly endowed with sympathetic nerves, this intra-glomus vessel links up with a thin-walled vein that eventually drains into larger superficial skin veins. When the core temperature rises, adrenergic sympathetic tone decreases, opening the intra-glomus vessels. Warm blood then flows directly from artery to vein, bypassing the capillary beds. In this way, the glomus bodies modulate heat exchange and work in parallel with the capillaries and A-V Shunts of the skin.
Onychoscopy and nail fold capillaroscopy
Published in Archana Singal, Shekhar Neema, Piyush Kumar, Nail Disorders, 2019
Glomus tumor is a benign vascular hamartoma arising from the modified smooth muscle cells of the glomus body. Onychoscopic features include: Irregular bluish patch with discrete linear vascular structures (Figure 7.25)24UV light dermoscopy: “Pink glow” indicating vascular nature of the tumor25Intraoperative onychoscopy: Ramified capillaries over a blue background. This is typically useful for determining the tumor margins as these ramified capillaries disappear abruptly at the margins.26
Skin and soft tissue
Published in Tor Wo Chiu, Stone’s Plastic Surgery Facts, 2018
Glomus is Latin for ‘ball’. A glomus body is a highly convoluted arteriovenous shunt (i.e. no intervening capillary bed) with rich sympathetic innervation. It is involved with thermoregulatory activity. The central coiled endothelial canal is surrounded by smooth muscle and rounded specialised pericytes called glomus cells; there are numerous unmyelinated nerve fibres. A glomus tumour is an encapsulated dermal tumour (strictly a hamartoma) of sheets of proliferating glomus cells surrounding small vascular channels. They arise from the arterial portion of the glomus body. These were originally described as ‘painful subcutaneous tubercles’ by William Wood in 1812.
Extradigital glomus tumor of the anterior knee
Published in Case Reports in Plastic Surgery and Hand Surgery, 2020
The glomus body is a neuro-myo-arterial apparatus in the subcutis and reticular dermis which participates in thermoregulatory control. It is composed of an arteriole and venule with multiple shunts, perivascular contractile glomus cells, and non-myelinated nerve fibers which influence vessel diameter through sympathetic tone [1]. In cold conditions, the glomus body assists in shunting blood away from the papillary dermis and skin surface, thereby decreasing heat loss from the body [2]. The converse is true for heat release or in conditions which provoke a flushing response.
Suprascapular glomus tumor: an unusual cause of chronic shoulder pain
Published in Case Reports in Plastic Surgery and Hand Surgery, 2022
Theodoros Floros, Konstantinos Perivoliotis, Athina Samara, Aikaterini Tsionga, Maria Ioannou, Ioannis Baloyiannis, Konstantinos Tepetes
Glomus tumors are rare mesenchymal neoplasms arising from the glomus body [8]. GTs typically develop between the 3rd and the 5th decade of life [9]. Due to the higher density in glomus bodies, the subungual area of the digits, is the most common anatomical area of GT development [10]. Extradigital GTs, though, are quite uncommon, consisting only a 26.7% rate of all new diagnoses [10]. Regarding gender allocation, subungual tumors are associated with a 2:1 female predominance, while extradigital GTs are more frequently diagnosed in male patients [10].