"Krause's glands Krause's glands are small, mucous accessory lacrimal glands that are found underneath the eyelid where the upper and lower conjuctivae meet. Their ducts unite into a rather long sinus which open into the fornix conjunctiva. There are approximately forty Krause glands in the region of the upper eyelid, and around 6 to 8 in the region of the lower lid. The function of these glands are to produce tears which are secreted onto the surface of the conjuctiva. There are rare instances of tumors associated with Krause's glands. They usually occur as retention cysts in cicatricial conditions of"
"turn to the nasolacrimal duct, which dumps them out into the nose. Lacrimal glands are also present in other mammals, such as horses. The lacrimal gland is a compound tubuloacinar gland, it is made up of many lobules separated by connective tissue, each lobule contains many acini. The acini contain only serous cells and produce a watery serous secretion. Each acinus consists of a grape-like mass of ""lacrimal gland cells"" with their apices pointed to a central lumen. The central lumen of many of the units converge to form intralobular ducts, and then they unite to form interlobular ducts. The"
"Lacritin Lacritin is a 12.3 kDa glycoprotein encoded in humans by the LACRT gene. Lacritin's discovery emerged from a screen for factors that stimulate tear protein secretion. Lacritin is a secreted protein found in tears and saliva. Lacritin also promotes tear secretion, the proliferation and survival of epithelial cells, and corneal wound healing Lacritin is thus a multifunctional prosecretory mitogen with cell survival activity. Natural or bacterial cleavage of lacritin releases a C-terminal fragment that is bactericidal. Most lacritin is produced by the lacrimal gland, including the accessory lacrimal gland of Wolfring. Some lacritin is produced by the meibomian gland,"
"Endocrine glands secrete substances that circulate through the blood stream. The glands secrete their products through basal lamina into the blood stream. Basil lamina typically can be seen a layer around the glands to which a million maybe more tiny blood vessels are attached. These glands often secrete hormones which play an important role in maintaining homeostasis. The pineal gland, thymus gland, pituitary gland, thyroid gland, and the two adrenal glands are all endocrine glands. Exocrine glands secrete their products through a duct onto an outer surface of the body, such as the skin or the gastrointestinal tract. Secretion is"
"except the lips, ear canal, prepuce, glans penis, labia minora, and clitoris. They are ten times smaller than apocrine sweat glands, do not extend as deeply into the dermis, and excrete directly onto the surface of the skin. The proportion of eccrine glands decreases with age. The clear secretion produced by eccrine sweat glands is termed sweat or ""sensible perspiration"". Sweat is mostly water, but it does contain some electrolytes, since it is derived from blood plasma. The presence of sodium chloride gives sweat a salty taste. The total volume of sweat produced depends on the number of functional glands"
"from sebaceous glands. Mammary glands use apocrine secretion to produce milk. Sweat glands are used to regulate temperature and remove waste by secreting water, sodium salts, and nitrogenous waste (such as urea) onto the skin surface. The main electrolytes of sweat are sodium and chloride, though the amount is small enough to make sweat hypotonic at the skin surface. Eccrine sweat is clear, odorless, and is composed of 98–99% water; it also contains NaCl, fatty acids, lactic acid, citric acid, ascorbic acid, urea, and uric acid. Its pH ranges from 4 to 6.8. On the other hand, the apocrine sweat"
"Tears Tearing (), lacrimation, or lachrymation () is the secretion of tears, a body fluid which often serves to clean and lubricate the eyes in response to an irritation of the eyes. Tears formed through crying are associated with strong internal emotions, such as sorrow, elation, love, awe, and pleasure. Laughing or yawning may also lead to the production of tears. In humans, the tear film coating the eye, known as the precorneal film, has three distinct layers, from the most outer surface: Having a thin tear film may prevent one's ability to wear contact lenses, as the amount of"
"glands contain a glandular portion and a duct portion, the structures of which can be used to classify the gland. Exocrine glands are named apocrine glands, holocrine glands, or merocrine glands based on how their products are secreted. Exocrine gland Exocrine glands are glands that produce and secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, and mucous. Exocrine glands are one of two types of glands in the human body, the other being endocrine glands, which secrete their products directly into the bloodstream. The liver and"
"glands are in the areola that surrounds the nipple in the female breast. These glands secrete an oily fluid that lubricates the nipple, and also secrete volatile compounds that are thought to serve as an olfactory stimulus for the newborn. During pregnancy and lactation these glands, also called Montgomery's glands, become enlarged. Meibomian glands, in the eyelids, secrete a form of sebum called meibum onto the eye, that slows the evaporation of tears. It also serves to create an airtight seal when the eyes are closed and its lipid quality also prevents the eyelids from sticking together. The meibomian glands"
"Lacrimal artery The lacrimal artery is an artery that arises close to the optic foramen, and is one of the largest branches derived from the ophthalmic artery. Not infrequently it is given off before the artery enters the orbit. It accompanies the lacrimal nerve along the upper border of the lateral rectus and supplies the lacrimal gland. Its terminal branches, escaping from the gland, are distributed to the eyelids and conjunctiva: of those supplying the eyelids, two are of considerable size and are named the lateral palpebral arteries; they run medially in the upper and lower lids respectively and anastomose"
"Exocrine gland Exocrine glands are glands that produce and secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, and mucous. Exocrine glands are one of two types of glands in the human body, the other being endocrine glands, which secrete their products directly into the bloodstream. The liver and pancreas are both exocrine and endocrine glands; they are exocrine glands because they secrete products—bile and pancreatic juice—into the gastrointestinal tract through a series of ducts, and endocrine because they secrete other substances directly into the bloodstream. Exocrine"
"Apocrine sweat gland An apocrine sweat gland (; from Greek ""apo–"" ""away"" and ""krinein"" ""to separate"") is composed of a coiled secretory portion located at the junction of the dermis and subcutaneous fat, from which a straight portion inserts and secretes into the infundibular portion of the hair follicle. In humans, apocrine sweat glands are found only in certain locations of the body: the axillae (armpits), areola and nipples of the breast, ear canal, eyelids, wings of the nostril, perianal region, and some parts of the external genitalia. Modified apocrine glands include the ciliary glands in the eyelids; the ceruminous"
"Sebaceous gland Sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals. In humans, they occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. The type of secretion of the sebaceous glands is referred to as holocrine. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Fordyce"
"Preorbital gland The preorbital gland is a paired exocrine gland found in many species of hoofed animals, which is homologous to the lacrimal gland found in humans. These glands are trenchlike slits of dark blue to black, nearly bare skin extending from the medial canthus of each eye. They are lined by a combination of sebaceous and sudoriferous glands, and they produce secretions which contain pheromones and other semiochemical compounds. Ungulates frequently deposit these secretions on twigs and grass as a means of communication with other animals. The preorbital gland serves different roles in different species. Pheromone-containing secretions from the"
"and found to be effective ""in vivo"", the potential exists for producing new antimicrobial agents against pathogenic skin microorganisms. Preorbital gland The preorbital gland is a paired exocrine gland found in many species of hoofed animals, which is homologous to the lacrimal gland found in humans. These glands are trenchlike slits of dark blue to black, nearly bare skin extending from the medial canthus of each eye. They are lined by a combination of sebaceous and sudoriferous glands, and they produce secretions which contain pheromones and other semiochemical compounds. Ungulates frequently deposit these secretions on twigs and grass as a"
"Phlegm Phlegm ( ""inflammation, humour caused by heat"") is a liquid secreted by the mucous membranes of mammals. Its definition is limited to the mucus produced by the respiratory system, excluding that from the nasal passages, and particularly that which is expelled by coughing (sputum). Phlegm is in essence a water-based gel consisting of glycoproteins, immunoglobulins, lipids and other substances. Its composition varies depending on climate, genetics, and state of the immune system. Its color can vary from transparent to pale or dark yellow and green, from light to dark brown, and even to dark grey depending on the constituents."
"SDC1. Involvement of a G-protein coupled receptor would explain the rapidity of lacritin signaling. Lacritin is a glycoprotein of the human tear film, and to a lesser extent of saliva, lung lavage and plasma. It is mainly produced by the lacrimal gland. Some lacritin also is produced by the meibomian gland, and also by epithelial cells of the conjunctiva and cornea. The lacritin gene (""LACRT"") is one of the most transcriptionally regulated genes in the human eye. Functional studies suggest a role in epithelial renewal of some non-germative epithelia. By flowing downstream through ducts, it may generate a 'proliferative field'."
"Apocrine Apocrine () is a term used to classify exocrine glands in the study of histology. Cells which are classified as apocrine bud their secretions off through the plasma membrane producing extracellular membrane-bound vesicles. The apical portion of the secretory cell of the gland pinches off and enters the lumen. It loses part of its cytoplasm in their secretions. Apocrine glands are found primarily in the breast of lactating mammals (i.e. the mammary glands are apocrine glands). Secretion occurs when the release of secretory materials is accompanied with loss of part of cytoplasm. Apocrine secretion is less damaging to the"
"Areolar gland Areolar glands or Glands of Montgomery are sebaceous glands in the areola surrounding the nipple. The glands make oily secretions (lipoid fluid) to keep the areola and the nipple lubricated and protected. Volatile compounds in these secretions may also serve as an olfactory stimulus for newborn appetite. The portions of the gland visible on the skin's surface are called ""Montgomery tubercles"". The round bumps are found in the areola, and on the nipple itself. They can become exposed and raised when the nipple is stimulated. The skin over the surface opening is lubricated and tends to be smoother"
"tears that are made in response to irritants to the eye, such as when chopping onions or getting poked in the eye. Psychic tears are produced by the lacrimal system and are the tears expelled during emotional states. The lacrimal system is made up of a secretory system, which produces tears, and an excretory system, which drains the tears. The lacrimal gland is primarily responsible for producing emotional or reflexive tears. As tears are produced, some fluid evaporates between blinks, and some is drained through the lacrimal punctum. The tears that are drained through the punctum will eventually be drained"
"menses (leaving from the vagina), sebum (from the sebaceous glands), alkaline fluid (from the Bartholin's glands), mucus (from the Skene's glands), vaginal lubrication from the vaginal wall and smegma. Smegma is a white substance formed from a combination of dead cells, skin oils, moisture and naturally occurring bacteria, that forms in the genitalia. In females this thickened secretion collects around the clitoris and labial folds. It can cause discomfort during sexual activity as it can cause the clitoral glans to stick to the hood, and is easily removed by bathing. Aliphatic acids known as copulins are also secreted in the"
"the poisonous secretion is released. Glands secreting a sugary liquid—the nectar—in flowers pollinated by insects are called nectaries. Nectaries may occur on the floral stalk or on any floral organ: sepal, petal, stamen, or ovary. The hydathode structures discharge water—a phenomenon called guttation through openings in margins or tips of leaves. The water flows through the xylem to its endings in the leaf and then through the intercellular spaces of the hydathode tissue toward the openings in the epidermis. Strictly speaking, such hydathodes are not glands because they are passive with regard to the flow of water. Some carnivorous plants"
"Salivary gland The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual) as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous or seromucous (mixed). In serous secretions, the main type of protein secreted is alpha-amylase, an enzyme that breaks down starch into maltose and glucose, whereas in mucous secretions the main protein secreted is mucin, which acts as a lubricant. In humans, between 0.5 and 1.5 litres of saliva are produced every day. The secretion of"
"Perspiration Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distributed over much of the body. In humans, sweating is primarily a means of thermoregulation, which is achieved by the water-rich secretion of the eccrine glands. Maximum sweat rates of an adult can be up to 2–4 liters per hour or 10–14 liters per day (10–15 g/min·m), but is less in children prior to puberty. Evaporation of sweat from"
"Sweat gland Sweat glands, also known as sudoriferous or sudoriparous glands, , are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial surface by way of a duct. There are two main types of sweat glands that differ in their structure, function, secretory product, mechanism of excretion, anatomic distribution, and distribution across species: Ceruminous glands (which produce ear wax), mammary glands (which produce milk), and ciliary glands in the eyelids are modified apocrine sweat glands. Generally, sweat glands consist of a"
"Meibomian gland The Meibomian glands (often written with a small ""m"" and also called tarsal glands) are a holocrine type of exocrine glands, at the rim of the eyelids inside the tarsal plate, responsible for the supply of meibum, an oily substance that prevents evaporation of the eye's tear film. Meibum prevents tear spillage onto the cheek, trapping tears between the oiled edge and the eyeball, and makes the closed lids airtight. There are approximately 50 glands on the upper eyelids and 25 glands on the lower eyelids. Dysfunctional meibomian glands often cause dry eyes, one of the more common"
"intestines, the large intestine, and conjunctiva in the upper eyelid. In the conjunctiva goblet cells are a source of mucin in tears and they also secrete different types of mucins onto the ocular surface. In the lacrimal glands, mucus is synthesized by acinar cells instead. Goblet cells are simple columnar epithelial cells, having a height of four times that of their width. The cytoplasm of goblet cells tends to be displaced toward the basal end of the cell body by the large mucin granules, which accumulate near the apical surface of the cell along the Golgi apparatus, which lies between"
"Tear gas Tear gas, formally known as a lachrymator agent or lachrymator (from the Latin ""lacrima"", meaning ""tear""), sometimes colloquially known as mace, is a chemical weapon that causes severe eye and respiratory pain, skin irritation, bleeding, and even blindness. In the eye, it stimulates the nerves of the lacrimal gland to produce tears. Common lachrymators include pepper spray (OC gas), PAVA spray (nonivamide), CS gas, CR gas, CN gas (phenacyl chloride), bromoacetone, xylyl bromide, syn-propanethial-S-oxide (from onions), and Mace (a branded mixture). Lachrymatory agents are commonly used for riot control. Their use in warfare is prohibited by various international"
"Eccrine sweat gland Eccrine glands (; from ""ekkrinein"" ""secrete""; sometimes called merocrine glands) are the major sweat glands of the human body, found in virtually all skin, with the highest density in palm and soles, then on the head, but much less on the trunk and the extremities. In other mammals, they are relatively sparse, being found mainly on hairless areas such as foot pads. They reach their peak of development in humans, where they may number 200–400/cm² of skin surface. They produce a clear, odorless substance, sweat, consisting primarily of water. Eccrine glands are composed of an intraepidermal spiral"
"strongly linked to reduced body odor, whereas those with wet, sticky earwax (Africans and Europeans) are prone to more body odor. Apocrine sweat gland An apocrine sweat gland (; from Greek ""apo–"" ""away"" and ""krinein"" ""to separate"") is composed of a coiled secretory portion located at the junction of the dermis and subcutaneous fat, from which a straight portion inserts and secretes into the infundibular portion of the hair follicle. In humans, apocrine sweat glands are found only in certain locations of the body: the axillae (armpits), areola and nipples of the breast, ear canal, eyelids, wings of the nostril,"
"only restricted areas, including the armpits and external genitalia. They are inactive until stimulated by hormonal changes in puberty. The apocrine gland secretes an oily fluid with proteins, lipids, and steroids that is odorless before microbial activity. It appears on the skin surface mixed with sebum, as sebaceous glands open into the same hair follicle. Unlike eccrine sweat glands, which secrete continuously, the apocrine glands secrete in periodic spurts. Apocrine sweat glands were originally thought to use only apocrine secretion: vesicles pinch off from the secretory cells, then degrade in the secretory lumen, releasing their product. More recent research has"
"Smegma Smegma (Greek ""smēgma"") is a combination of shed skin cells, skin oils, and moisture. It occurs in both male and female mammalian genitalia. In female bodies, it collects around the clitoris and in the folds of the labia minora; in males, smegma collects under the foreskin. The accumulation of sebum combined with dead skin cells forms smegma. Smegma clitoridis is defined as the secretion of the apocrine glands of the clitoris, in combination with desquamating epithelial cells. Glands that are located around the clitoris and the vulva majoris secrete sebum. If smegma is not removed frequently it can lead"
"is the most prevalent and is also called ""secretory IgA"" (sIgA). sIgA is the main immunoglobulin found in mucous secretions, including tears, saliva, sweat, colostrum and secretions from the genitourinary tract, gastrointestinal tract, prostate and respiratory epithelium. It is also found in small amounts in blood. The secretory component of sIgA protects the immunoglobulin from being degraded by proteolytic enzymes, thus sIgA can survive in the harsh gastrointestinal tract environment and provide protection against microbes that multiply in body secretions. sIgA can also inhibit inflammatory effects of other immunoglobulins. IgA is a poor activator of the complement system, and opsonises"