Skin
Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard in Toxicologic Pathology, 2018
Apocrine glands are simple sac-like or tubular glands with a coiled secretory component connected to a straight duct that opens to the hair follicle just below the opening at the skin surface. The secretory component has a large lumen lined by flattened cuboidal to low columnar epithelial cells containing lipid, glycogen, or pigment granules. In general, secretory activity is manifested by cytoplasmic profusions (secretory blebs) at the apical surface of these cells. Myoepithelial cells surround the secretory portion of the gland, which is innervated by postganglionic fibers of the sympathetic nervous system. The ductal segment has a narrow lumen lined by two layers of flattened cells. Apocrine glands are distributed throughout the skin of most mammals in contrast to humans where they are principally found in the axillary, pubic, and perianal areas (thought to represent vestigial scent glands) or in rodents where they are only present in the plantar areas. In animals, apocrine glands may become specialized, such as the anal sac glands of dogs and cats, the ceruminous glands of the external ear canal, and the glands of Moll in the eyelids.
Integumentary system
Aida Lai in Essential Concepts in Anatomy and Pathology for Undergraduate Revision, 2018
Sweat glandsApocrine glands – open into hair follicles– found in axilla, groin and anal regionEccrine glands – open on to surface of skin– regulate body temperature
The Cause of Pressure Sores
J G Webster in Prevention of Pressure Sores, 2019
The dermis is a vascular layer that lies beneath the epidermis. The surface between the dermis and the epidermis is usually uneven, because the epidermis has ridges projecting inward and the dermis has finger-like papillae passing into the spaces between the ridges (Hole 1987). These papillae increase the mechanical strength of the skin, binding the epidermis to the underlying tissues. The dermis is composed of mostly fibrous connective tissue that includes tough collagenous fibers and elastic fibers that are surrounded by a gel-like substance (Hole 1987). This also adds to the strength of skin. The dermis ranges from 0.5 mm thick in the eyelids to 3.0 mm on the soles, the average being 1.0 to 2.0 mm thick. It contains two kinds of sweat glands, the apocrine and eccrine glands. Eccrine glands are connected to pores on the surface of the epidermis. They respond throughout life by secreting sweat to cool the skin’s surface when the body’s temperature becomes elevated due to environmental heat or physical exercise. The apocrine glands are connected to hair follicles. They occur mostly in the armpits and groin. Other structures contained in the dermis include the lymphatics, nerves, hair follicles, smooth muscle fibers, and striated muscle fibers.
Physiology of sweat gland function: The roles of sweating and sweat composition in human health
Published in Temperature, 2019
Lindsay B. Baker
The apocrine gland is a second type of sweat gland, which was first recognized by Krause in 1844 and later named by Schiefferdecker in 1922 [20,21]. Apocrine sweat glands are located primarily in the axilla, breasts, face, scalp, and the perineum [21,22]. As shown in Figure 1, these glands differ from eccrine glands in that they are larger and open into hair follicles instead of onto the skin surface [12]. In addition, although present from birth, the secretory function of apocrine glands does not begin until puberty [23]. Apocrine glands produce viscous, lipid-rich sweat, which is also comprised of proteins, sugars, and ammonia [21,23]. The function of apocrine glands in many species is generally regarded as scent glands involved in production of pheromones (body odor), although this social/sexual function is rudimentary in humans. Apocrine gland innervation is poorly understood, but isolated sweat glands have been found to respond equally to adrenergic and cholinergic stimuli [23].
Anti-ageing peptides and proteins for topical applications: a review
Published in Pharmaceutical Development and Technology, 2022
Mengyang Liu, Shuo Chen, Zhiwen Zhang, Hongyu Li, Guiju Sun, Naibo Yin, Jingyuan Wen
Glands are partial appendages, and the sebaceous glands are the small oil-producing glands directly open to the skin's surface and attach to hair follicles. These glands are most abundant on the scalp and face. They secrete an antibacterial substance known as sebum, a mixture of free fatty acids, glycerides, and cholesterol (Wertz 2018). Sebum acts as a lubricant and is the source of SC plasticizing lipids. The essential function of sebum is to maintain the pH of the skin’s surface (Ma et al. 2019). Sweat glands are present in the lower layers of the dermis and are responsible for temperature regulation. Distributed all over the body, except around the areola, secretions from sweat glands are a diluted salt solution with a pH of around 5 (Ma et al. 2019). Conversely, the apocrine glands are only located in areas such as the armpit and perianal, and they are usually larger than other counterparts (Farah et al. 2020). These appendages also change during puberty, affecting the permeation of the skin (Hirt et al. 2019).
Primary apocrine adenocarcinoma of the lacrimal sac: an extremely rare variant of lacrimal sac neoplasm
Published in Orbit, 2022
Md. Shahid Alam, Vazhipokkil Anju Chandran, Subramanian KrishnaKumar
Primary lacrimal sac malignancies are extremely rare. A total of about 700 cases have been reported in the literature till date. Most of these tumours are of epithelial origin. The tumors mostly present with a mass or swelling in the lacrimal sac area with or without watering. Amongst the epithelial tumours, squamous carcinoma is the most common variant, while tumours of glandular origin like adenocarcinoma are seldom seen.1 Apocrine adenocarcinoma is an extremely rare sweat gland carcinoma. They usually arise in the area of high sweat gland density like axilla but have been reported elsewhere in the body including scalp, forehead, eyelid, upper lip, submandibular skin, chest, pubic skin, nipple, arm, wrist, and finger.2 In the periocular and adnexal area, they have been reported in the eyelid and caruncular region.3–7 To the best of authors’ knowledge, there is only a single case report of apocrine adenocarcinoma arising from the lacrimal sac.8 We herewith report the second case of this extremely rare tumor arising from the lacrimal sac. We feel that this report would further expand the horizon of histopathological variants of lacrimal sac malignancies and would aid in tailoring down the management. The patient gave consent for publication of his photograph for research purpose and the case report adhered to the tenets of Declaration of Helsinki.
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