|
Bowman's Glands
Olfactory glands, also known as Bowman's glands, are a type of nasal gland situated in the part of the olfactory mucosa beneath the olfactory epithelium, that is the lamina propria, a connective tissue also containing fibroblasts, blood vessels and bundles of fine axons from the olfactory neurons. An olfactory gland consists of an acinus in the lamina propria and a secretory duct going out through the olfactory epithelium. Electron microscopy studies show that olfactory glands contain cells with large secretory vesicles. Olfactory glands secrete the gel-forming mucin protein MUC5B. They might secrete proteins such as lactoferrin, lysozyme, amylase and IgA, similarly to serous glands. The exact composition of the secretions from olfactory glands is unclear, but there is evidence that they produce odorant-binding protein. Function The olfactory glands are tubuloalveolar glands surrounded by olfactory receptors Olfactory receptors (ORs), also known as odorant receptors, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory System
The olfactory system, is the sensory nervous system, sensory system used for the sense of smell (olfaction). Olfaction is one of the special senses directly associated with specific organs. Most mammals and reptiles have a main olfactory system and an accessory olfactory system. The main olfactory system detects airborne substances, while the accessory system senses fluid-phase stimuli. The senses of smell and taste (gustatory system) are often referred to together as the chemosensory system, because they both give the brain information about the chemical composition of objects through a process called transduction (physiology), transduction. Structure Peripheral The peripheral olfactory system consists mainly of the nostrils, ethmoid bone, nasal cavity, and the olfactory epithelium (layers of thin tissue covered in mucus that line the nasal cavity). The primary components of the layers of epithelial tissue are the mucous membranes, olfactory glands, olfactory receptor neurons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MUC5B
Mucin-5B (MUC-5B) is a protein that in humans is encoded by the ''MUC5B'' gene and by the ''Muc5b'' gene in the mouse. It is one of the five gel-forming mucins. MUC-5B can be found in whole saliva, normal lung mucus, and cervical mucus. In some diseases, such as COPD, chronic rhinosinusitis (CRS), and ''H. pylori''-associated gastric disease, the gene has been found to be upregulated, and this may be related to the pathogenesis of these conditions. Synthesis All mucins are synthesized in secretory cells known as goblet cell Goblet cells are simple columnar epithelial cells that secrete gel-forming mucins, like mucin 2 in the lower gastrointestinal tract, and mucin 5AC in the respiratory tract. The goblet cells mainly use the merocrine method of secretion, secre ...s or mucous cells, depending on the tissue location. Their creation, while still not completely understood, begins in the endoplasmic reticulum. From there, the Golgi apparatus builds the O-linked glycans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sir William Bowman, 1st Baronet
Sir William Bowman, 1st Baronet (20 July 1816 – 29 March 1892) was an English surgeon, histologist and anatomist. He is best known for his research using microscopes to study various human organs, though during his lifetime he pursued a successful career as an ophthalmologist. Life Born in Nantwich, Cheshire, third son of a banker and amateur botanist/geologist, Bowman attended Hazelwood School near Birmingham from 1826.Hale-White, W. (1935) "Sir William Bowman", pp. 177–188; in ''Great Doctors of the Nineteenth Century'', Edward Arnold & Co A childhood accident involving gunpowder is supposed to have interested him in medicine, and he was apprenticed to surgeon Joseph Hodgson at Birmingham General Hospital in 1832. He left Birmingham in 1837 to further his training as a surgeon and attended King's College London, where he served as a prosector under Robert Bentley Todd, a Professor of physiology. His earliest notable work was on the structure of striated muscle, for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sustentacular Cell
A sustentacular cell is a type of cell primarily associated with structural support, they can be found in various tissues. * Sustentacular cells of the olfactory epithelium (also called supporting cells or Sertoli cells) have been shown to be involved in the phagocytosis of dead neurons, odorant transformation and xenobiotic metabolism. * One type of sustentacular cell is the Sertoli cell, in the testicle. It is located in the walls of the seminiferous tubules and supplies nutrients to sperm. They are responsible for the differentiation of spermatids, the maintenance of the blood-testis barrier, and the secretion of inhibin, androgen-binding protein and Müllerian-inhibiting factor. * The organ of Corti in the inner ear and taste bud Taste buds are clusters of taste receptor cells, which are also known as gustatory cells. The taste receptors are located around the small structures known as papillae found on the upper surface of the tongue, soft palate, upper esopha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory Receptors
Olfactory receptors (ORs), also known as odorant receptors, are chemoreceptors expressed in the cell membranes of olfactory receptor neurons and are responsible for the detection of odorants (for example, compounds that have an odor) which give rise to the sense of smell. Activated olfactory receptors trigger nerve impulses which transmit information about odor to the brain. In vertebrates, these receptors are members of the class A rhodopsin-like family of G protein-coupled receptors (GPCRs). The olfactory receptors form the largest multigene family in vertebrates consisting of around 400 genes in humans and 1400 genes in mice. In insects, olfactory receptors are members of an unrelated group of ligand-gated ion channels. Expression In vertebrates, the olfactory receptors are located in both the cilia and synapses of the olfactory sensory neurons and in the epithelium of the human airway. Sperm cells also express odorant receptors, which are thought to be involved in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odorant-binding Protein
Odorant-binding proteins (OBPs) are small (10 to 30 kDa) soluble proteins secreted by auxiliary cells surrounding olfactory receptor neurons, including the nasal mucus of many vertebrate species and in the sensillar lymph of chemosensory sensilla of insects. OBPs are characterized by a specific protein domain that comprises six α-helices joined by three disulfide bonds. Although the function of the OBPs as a whole is not well established, it is believed that they act as odorant transporters, delivering the odorant molecules to olfactory receptors in the cell membrane of sensory neurons. The olfactory receptors of terrestrial animals exist in an aqueous environment, yet detect odorants that are primarily hydrophobic. The aqueous solubility of hydrophobic odorants is greatly enhanced via odorant-binding proteins, which exist in the extracellular fluid surrounding the odorant receptors. This family is composed of pheromone binding proteins (PBP), which are male-specific and assoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serous Glands
Serous glands secrete serous fluid. They contain serous acini, a grouping of serous cells that secrete serous fluid, isotonic with blood plasma, that contains enzymes such as alpha-amylase. Serous glands are most common in the parotid gland and lacrimal gland but are also present in the submandibular gland and, to a far lesser extent, the sublingual gland. Structure Serous acinar cells Serous acinar cells are the primary secretory cells of serous glands. They have a characteristic pyramidal shape, with a broad base that rests on the basement membrane and a narrow apex that faces the lumen of the acinus. These cells typically form spherical or tubular structures called acini (singular: acinus), which are the basic functional units of exocrine glands. Histologically, serous acinar cells exhibit: * A round, basally located nucleus * Extensive rough endoplasmic reticulum in the basal cytoplasm, giving it a basophilic appearance in H&E stains * Numerous secretory granules ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amylase
An amylase () is an enzyme that catalysis, catalyses the hydrolysis of starch (Latin ') into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of starch but little sugar, such as rice and potatoes, may acquire a slightly sweet taste as they are chewed because amylase degrades some of their starch into sugar. The pancreas and salivary gland make amylase (alpha amylase) to hydrolyse dietary starch into disaccharides and trisaccharides which are converted by other enzymes to glucose to supply the body with energy. Plants and some bacteria also produce amylase. Specific amylase proteins are designated by different Greek letters. All amylases are glycoside hydrolases and act on α-1,4-glycosidic bonds. Classification α-Amylase The α-amylases () (CAS registry number, CAS 9014–71–5) (alternative names: 1,4-α-D-glucan glucanohydrolase; glycogenase) are calcium metallop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysozyme
Lysozyme (, muramidase, ''N''-acetylmuramide glycanhydrolase; systematic name peptidoglycan ''N''-acetylmuramoylhydrolase) is an antimicrobial enzyme produced by animals that forms part of the innate immune system. It is a glycoside hydrolase that catalyzes the following process: : Hydrolysis of (1→4)-β-linkages between ''N''-acetylmuramic acid and ''N''-acetyl-D-glucosamine residues in a peptidoglycan and between ''N''-acetyl-D-glucosamine residues in chitodextrins Peptidoglycan is the major component of gram-positive bacterial cell wall. This hydrolysis in turn compromises the integrity of bacterial cell walls causing lysis of the bacteria. Lysozyme is abundant in secretions including tears, saliva, human milk, and mucus. It is also present in cytoplasmic granules of the macrophages and the polymorphonuclear neutrophils (PMNs). Large amounts of lysozyme can be found in egg white. C-type lysozymes are closely related to alpha-lactalbumin, α-lactalbumin in sequence and st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucin
Mucins () are a family of high molecular weight, heavily glycosylated proteins ( glycoconjugates) produced by epithelial tissues in most animals. Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell signalling to forming chemical barriers. They often take an inhibitory role. Some mucins are associated with controlling mineralization, including nacre formation in mollusks, calcification in echinoderms and bone formation in vertebrates. They bind to pathogens as part of the immune system. Overexpression of the mucin proteins, especially MUC1, is associated with many types of cancer. Although some mucins are membrane-bound due to the presence of a hydrophobic membrane-spanning domain that favors retention in the plasma membrane, most mucins are secreted as principal components of mucus by mucous membranes or are secreted to become a component of saliva. Gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nasal Gland
The nasal glands are the Exocrine gland, seromucous glands in the Respiratory system, respiratory region of the Nasal mucosa, nasal mucous membrane. The three major types of nasal glands are anterior serous glands, seromucous glands, and Bowman glands. Glands Anterior serous glands The anterior nasal glands help moisturize the nasal mucosa. Seromucous glands The seromucous glands are found primarily in the anterior nasal cavity, and they are also found within the nasal cavity. Bowman glands The Bowman glands are serous glands that help the olfactory region with smelling. NotesMedical Definition References {{Authority control Glands Nose, glands Otorhinolaryngology ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acinus
An acinus (; : acini; adjective, acinar or acinous) refers to any cluster of cells that resembles a many-lobed "berry", such as a raspberry ('' acinus'' is Latin for "berry"). The berry-shaped termination of an exocrine gland, where the secretion is produced, is acinar in form, as is the alveolar sac containing multiple alveoli in the lungs. Exocrine glands Acinar exocrine glands are found in many organs, including: * the stomach * the sebaceous gland of the scalp * the salivary glands of the tongue * the liver * the lacrimal glands * the mammary glands * the pancreas * the bulbourethral (Cowper's) glands The thyroid follicles can also be considered of acinar formation but in this case the follicles, being part of an ''endocrine'' gland, act as a hormonal deposit rather than to facilitate secretion. Mucous acini usually stain pale, while serous acini usually stain dark. Lungs The end of the terminal bronchioles in the lungs The lungs are the primary organs of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
