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Lactiferous Duct
Lactiferous ducts are ducts that converge and form a branched system connecting the nipple to the lobules of the mammary gland. When lactogenesis occurs, under the influence of hormones, the milk is moved to the nipple by the action of smooth muscle contractions along the ductal system to the tip of the nipple. They are also referred to as ''galactophores'', ''galactophorous ducts'', ''mammary ducts'', ''mamillary ducts'' or ''milk ducts''. Structure Lactiferous ducts are lined by a columnar epithelium supported by myoepithelial cells. Prior to 2005, it was thought within the areola the lactiferous duct would dilate to form the lactiferous sinus in which milk accumulates between breastfeeding sessions. However past studies have shown that the lactiferous sinus does not exist. Function The columnar epithelium plays a key role in balancing milk production, milk stasis and reabsorption. The cells of the columnar epithelium form tight junctions which are regulated by hormones and loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammary Gland
A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primates (for example, humans and chimpanzees), the udder in ruminants (for example, cows, goats, sheep, and deer), and the dugs of other animals (for example, dogs and cats). Lactorrhea, the occasional production of milk by the glands, can occur in any mammal, but in most mammals, lactation, the production of enough milk for nursing, occurs only in phenotypic females who have gestated in recent months or years. It is directed by hormonal guidance from sex steroids. In a few mammalian species, male lactation can occur. With humans, male lactation can occur only under specific circumstances. Mammals are divided into 3 groups: prototherians, metatherians, and eutherians. In the case of prototherians, both males and females have functional m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prolactin
Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pituitary gland in response to eating, mating, estrogen treatment, ovulation and nursing. It is secreted heavily in pulses in between these events. Prolactin plays an essential role in metabolism, regulation of the immune system and pancreatic development. Discovered in non-human animals around 1930 by Oscar Riddle and confirmed in humans in 1970 by Henry Friesen, prolactin is a peptide hormone, encoded by the ''PRL'' gene. In mammals, prolactin is associated with milk production; in fish it is thought to be related to the control of water and salt balance. Prolactin also acts in a cytokine-like manner and as an important regulator of the immune system. It has important cell cycle-related functions as a growth-, differentiating- and ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subareolar Abscess
Also called Zuska's disease (only nonpuerperal case), subareolar abscess is a subcutaneous abscess of the breast tissue beneath the areola of the nipple. It is a frequently aseptic inflammation and has been associated with squamous metaplasia of lactiferous ducts. The term is usually understood to include breast abscesses located in the retroareolar region or the periareolar region but not those located in the periphery of the breast. Subareolar abscess can develop both during lactation or extrapuerperal, the abscess is often flaring up and down with repeated fistulation. Pathophysiology 90% of cases are smokers, however only a very small fraction of smokers appear to develop this lesion. It has been speculated that either the direct toxic effect or hormonal changes related to smoking could cause squamous metaplasia of lactiferous ducts. It is not well established whether the lesion regresses after smoking cessation. Extrapuerperal cases are often associated with hyperprolact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duct Ectasia
Duct ectasia of the breast, mammary duct ectasia or plasma cell mastitis is a condition that occurs when a milk duct beneath the nipple widens, the duct walls thicken, and the duct fills with fluid. This is the most common cause of greenish discharge. Mammary duct ectasia can mimic breast cancer. It is a disorder of peri- or post-menopausal age. ''Duct ectasia syndrome'' is a synonym for nonpuerperal mastitis, but the term has also been occasionally used to describe special cases of fibrocystic diseases or mastalgia or as a wastebasket definition of benign breast disease. Correlation of duct widening with the "classical" symptoms of duct ectasia syndrome is unclear. However, duct widening was recently very strongly correlated with noncyclic breast pain. Duct diameter is naturally variable, subject to hormonal interactions. Duct ectasia syndrome in the classical meaning is associated with additional histological changes. Symptoms Signs of duct ectasia can include nipple retracti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection. Infections can be caused by a wide range of pathogens, most prominently bacteria and viruses. Hosts can fight infections using their immune system. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response. Specific medications used to treat infections include antibiotics, antivirals, antifungals, antiprotozoals, and antihelminthics. Infectious diseases resulted in 9.2 million deaths in 2013 (about 17% of all deaths). The branch of medicine that focuses on infections is referred to as infectious disease. Types Infections are caused by infectious agents (pathogens) including: * Bacteria (e.g. '' Mycobacterium tubercul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonpuerperal Mastitis
The term nonpuerperal mastitis describes inflammatory lesions of the breast (mastitis) that occur unrelated to pregnancy and breastfeeding. It is sometimes equated with duct ectasia, but other forms can be described. Types Duct ectasia—periductal mastitis complex ''Duct ectasia'' in the literal sense (literally: duct widening) is a very common and thus rather unspecific finding, increasing with age. However, in the way in which the term is mostly used, duct ectasia is an inflammatory condition of the larger-order lactiferous ducts. It is considered likely that the condition is associated with aseptic (chemical) inflammation related to the rupture of ducts or cysts. It is controversial whether duct dilation occurs first and leads to secretory stasis and subsequent periductal inflammation or whether inflammation occurs first and leads to an inflammatory weakening of the duct walls and then stasis. When the inflammation is complicated by necrosis and secondary bacterial infection, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resorption
Resorption is the absorption of cells or tissue into the circulatory system, usually by osteoclasts. Types of resorption include: * Bone resorption * Herniated Disc Resorption * Tooth resorption * Fetal resorption * Blood resorption See also * Nutrient resorption In plants Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plant ..., in plants References Set index articles {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastalgia
Breast pain is the symptom of discomfort in either one or both breasts. Pain in both breasts is often described as ''breast tenderness'', is usually associated with the menstrual period and is not serious. Pain that involves only one part of a breast is more concerning, particularly if a hard mass or nipple discharge is also present. Causes may be related to the menstrual cycle, birth control pills, hormone therapy, or psychiatric medication. Pain may also occur in those with large breasts, during menopause, and in early pregnancy. In about 2% of cases breast pain is related to breast cancer. Diagnosis involves examination, with medical imaging if only a specific part of the breast hurts. In more than 75% of people the pain resolves without any specific treatment. Otherwise treatments may include paracetamol or NSAIDs. A well fitting bra may also help. In those with severe pain tamoxifen or danazol may be used. About 70% of women have breast pain at some point in time. Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraductal Papilloma
Intraductal papillomas of the breast are benign lesions with an incidence of approximately 2-3% in humans. They result from abnormal proliferation of the epithelial cells lining the breast ducts. Two types of intraductal papillomas are generally distinguished. The central type develops near the nipple. They are usually solitary and often arise in the years nearing menopause. On the other hand, the peripheral type are often multiple papillomas arising at the peripheral ducts, and are usually found in younger women. The peripheral type are associated with a higher risk of malignancy. They are the most common cause of bloody nipple discharge in women age 20-40 and generally do not show up on mammography Mammography (also called mastography) is the process of using low-energy X-rays (usually around 30 kVp) to examine the human breast for diagnosis and screening. The goal of mammography is the early detection of breast cancer, typically through ... due to their small size. They m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllodes Tumor
Phyllodes tumors (from Greek: ''phullon'' leaf), also cystosarcoma phyllodes, cystosarcoma phylloides and phylloides tumor, are typically large, fast-growing masses that form from the periductal stromal cells of the breast. They account for less than 1% of all breast neoplasms. Presentation This is predominantly a tumor of adult women, with very few examples reported in adolescents. Patients typically present with a firm, palpable mass. These tumors are very fast-growing, and can increase in size in just a few weeks. Occurrence is most common between the ages of 40 and 50, prior to menopause. This is about 15 years older than the typical age of patients with fibroadenoma, a condition with which phyllodes tumors may be confused. They have been documented to occur at any age below 12 years. Diagnosis Classification Phyllodes tumors are a fibroepithelial tumor composed of an epithelial and a cellular stromal component. They may be considered benign, borderline, or malignant dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ductal Carcinoma In Situ
Ductal carcinoma in situ (DCIS), also known as intraductal carcinoma, is a pre-cancerous or non-invasive cancerous lesion of the breast. DCIS is classified as Stage 0. It rarely produces symptoms or a breast lump one can feel, typically being detected through screening mammography. It has been diagnosed in a significant percentage of men (see male breast cancer). In DCIS, abnormal cells are found in the lining of one or more milk ducts in the breast. ''In situ'' means "in place" and refers to the fact that the abnormal cells have not moved out of the mammary duct and into any of the surrounding tissues in the breast ("pre-cancerous" refers to the fact that it has not yet become an invasive cancer). In some cases, DCIS may become invasive and spread to other tissues, but there is no way of determining which lesions will remain stable without treatment, and which will go on to become invasive. DCIS encompasses a wide spectrum of diseases ranging from low-grade lesions that are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breast Cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a red or scaly patch of skin. In those with distant spread of the disease, there may be bone pain, swollen lymph nodes, shortness of breath, or yellow skin. Risk factors for developing breast cancer include obesity, a lack of physical exercise, alcoholism, hormone replacement therapy during menopause, ionizing radiation, an early age at first menstruation, having children late in life or not at all, older age, having a prior history of breast cancer, and a family history of breast cancer. About 5–10% of cases are the result of a genetic predisposition inherited from a person's parents, including BRCA1 and BRCA2 among others. Breast cancer most commonly develops in cells from the lining of milk ducts and the lobules that supply ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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