Home > Medicine > Anatomy and Physiology > Anatomy and Physiology

Topic:mammary gland

mammary gland. Wikimedia Commons (Public Domain)

Visit our new topic page about mammary gland

mammary gland

The Columbia Encyclopedia, Sixth Edition | Date: 2008

mammary gland organ of the female mammal that produces and secretes milk for the nourishment of the young. A mammal may have from 1 to 11 pairs of mammary glands, depending on the species. Generally, those mammals that bear larger litters have more glands. The mammary gland of the cow and of some other mammals is known as the udder.

In humans, there is one pair of mammary glands, also known as mammae, or breasts. They are rudimentary in both sexes until the age of puberty when, in response to ovarian hormones, they begin to develop in the female. During pregnancy, they distend still further in preparation for nursing the infant. Pregnant women are prevented from lactating (producing milk) by the presence in the blood of high levels of estrogen and progesterone , secreted by the placenta until birth occurs.

After birth, response to prolactin, the milk-stimulating hormone, is no longer inhibited by placental hormones, and lactation begins. Mammary tissue contains between 15 and 20 compartments called lobes, each of which is divided into smaller compartments called lobules. The lobes and lobules are connected by a network of tubes whose cells manufacture the liquid and fatty substances that form milk. The tubes of each lobe connect with a duct, and all ducts lead to the nipple, where the milk is secreted when the nipple is sucked by the young. The letdown of milk during the nursing process is aided by oxytocin , a hormone secreted by the pituitary. The physical force of an infant's sucking on the breast is a major stimulus to milk production. Disorders of the mammary gland include mastitis and breast cancer .

Author not available, MAMMARY GLAND., The Columbia Encyclopedia, Sixth Edition 2008

Related newspaper, magazine, and journal articles from HighBeam Research

	Chemoprevention of Breast Cancer, Proteomic Discovery of Genistein Action in the Rat Mammary Gland1-3 The Journal of Nutrition; 12/1/2005; Rowell, Craig; Carpenter, D Mark; Lamartiniere, Coral A; 5701 words ; ABSTRACT Genistein, the primary isoflavone component of soy, consumed in the diet during the prepubertal period only, and the combined prepubertal and adult periods, suppresses chemically induced mammary cancer in rats. Gestational or adult-only exposures do not provide protection. An inverse Read more
	Dietary Exposure to Whey Proteins Alters Rat Mammary Gland Proliferation, Apoptosis, and Gene Expression during Postnatal Development1 The Journal of Nutrition; 12/1/2004; Eason, Renea R; Velarde, Michael C; Chatman, Leon Jr; Till, S Reneé; Et al; 6653 words ; ABSTRACT We have found that AIN-93G diets made with whey protein hydrolysate (WPH) reduce 7,12-dimethyl-benz[a]anthracene (DMBA)-induced tumor incidence in Sprague-Dawley (Harlan) rats relative to those fed a diet with casein (CAS). Herein, we replicated these findings in another Sprague-Dawley Read more
	Prenatal bisphenol a exposure induces preneoplastic lesions in the mammary gland in Wistar rats.(Research) Environmental Health Perspectives; 1/1/2007; Durando, Milena Kass, Laura Piva, Julio Sonnenschein, Carlos Soto, Ana M. Luque, Enrique H. Munoz-de-Toro, Monica; 6720 words ; BACKGROUND: Humans are routinely exposed to bisphenol A (BPA), an estrogenic compound that leaches from dental materials, food and beverage containers, and other consumer products. Prenatal exposure to BPA has produced long-lasting and profound effects on rodent hormone-dependent tissues that are Read more
	Perinatal bisphenol a exposure increases estrogen sensitivity of the mammary gland in diverse mouse strains.(Research)(Report) Environmental Health Perspectives; 4/1/2007; Wadia, Perinaaz R. Vandenberg, Laura N. Schaeberle, Cheryl M. Rubin, Beverly S. Sonnenschein, Carlos Soto, Ana M.; 6864 words ; BACKGROUND: Studies of low-dose effects of xenoestrogens have yielded conflicting results that may be attributed to differences in estrogen sensitivity between the rodent strains examined. Perinatal exposure of CD-1 mice to low doses of the xenoestrogen bisphenol A (BPA) alters peripubertal mammary Read more
	Adenoviral-mediated transfer of a lysostaphin gene into the goat mammary gland Journal of Dairy Science; 7/1/2002; Fan, W; Plaut, K; Bramley, A J; Barlow, J W; Kerr, D E; 4990 words ; ABSTRACT As a step toward preventing and curing Staphylococcus aureus mastitis, an adenoviral-mediated gene transfer technique was used to enable mammary cells to synthesize and secrete lysostaphin, an anti-staphylococcal protein. A lysostaphin gene, modified for eukaryotic expression of the Read more
	Mammary Gland Expression of Antibacterial Peptide Genes to Inhibit Bacterial Pathogens Causing Mastitis Journal of Dairy Science; 11/1/2007; Zhang, J X; Zhang, S F; Wang, T D; Guo, X J; Hu, R L; 5097 words ; ABSTRACT As a step toward prevention of bovine mastitis, a plasmid-mediated gene transfer technique was used to enable mammary cells to synthesize and secrete bovine lactoferricin and bovine tracheal antibacterial peptides. For this purpose, a series of mammary tissue-specific expression vectors, Read more
	A Rat Mammary Tumor Model Induced by the Organophosphorous Pesticides Parathion and Malathion, Possibly through Acetylcholinesterase Inhibition. Environmental Health Perspectives; 5/1/2001; Cabello, Gertrudis Valenzuela, Mario Vilaxa, Arnaldo Duran, Viviana Rudolph, Isolde Hrepic, Nicolas Calaf, Gloria; 7080 words ; Environmental chemicals may be involved in the etiology of breast cancers. Many studies have addressed the association between cancer in humans and agricultural pesticide exposure. Organophosphorous pesticides have been used extensively to control mosquito plagues. Parathion and malathion are Read more
	Conjugated Linoleic Acid Induces Mast Cell Recruitment during Mouse Mammary Gland Stromal Remodeling1,2 The Journal of Nutrition; 5/1/2007; Russell, Joshua S; McGee, Sibel Oflazoglu; Ip, Margot M; Kuhlmann, Dietrich; Masso-Welch, Patricia A; 6033 words ; Abstract Conjugated linoleic acid (CLA) is a dietary chemopreventive agent that induces apoptosis in the mammary adipose vascular endothelium and decreases mammary brown adipose tissue (BAT) and white adipose tissue (WAT). To determine onset and extent of stromal remodeling, we fed CD2F1/Cr mice Read more
	Milk synthetic response of the bovine mammary gland to an increase in the local concentration of arterial glucose Journal of Dairy Science; 3/1/2002; Cant, J P; Trout, D R; Qiao, F; Purdie, N G; 1864 words ; ABSTRACT Concentrations of glucose in the external iliac artery feeding one udder half of 14 midlactation Holstein cows were increased by infusion to test the following three hypotheses of mammary function: 1) that mammary glands control their blood supply to maintain intracellular energy balance, Read more
	Expression of Albumin in Nonhepatic Tissues and its Synthesis by the Bovine Mammary Gland Journal of Dairy Science; 2/1/2005; Shamay, A; Homans, R; Fuerman, Y; Levin, I; Et al; 4366 words ; ABSTRACT Albumin is a well-characterized product of the liver. In the present study, objectives were to determine if the albumin gene is also expressed in various nonhepatic tissues in the bovine; whether mammary gland epithelial cells synthesize albumin; and how its synthesis is affected by bovine Read more

See all related premium articles

Related entries from encyclopedias, dictionaries, and thesauruses

	mammary gland Britannica Concise Encyclopedia Milk-producing gland of female mammals, usually present but undeveloped ... derived from a modification of sweat glands . The mammary gland of a woman who has not borne children consists of ... are largely replaced by connective tissue and fat. mammary gland mammary gland ... Read more
	mammary glands World Encyclopedia mammary glands See breast Read more
	exocrine gland A Dictionary of Psychology exocrine gland n. A gland that originates in epithelial tissue and secretes ... directly into the bloodstream. See Bartholin's gland , gastric gland , mammary gland , salivary gland , sweat gland . Compare endocrine gland .[From Greek exo ... Read more
	apocrine gland A Dictionary of Zoology apocrine gland A type of gland in which the apical part, from which the secretion is released, breaks down during the secretion process. The gland opens at the surface of the skin near, but not within, hair follicles. From the opening a long tubular invagination extends into the dermis (see INTEGUMENT ) ... . Read more
	sweat gland Britannica Concise Encyclopedia ... continuously secrete a fatty sweat. Certain specialized glands, such as mammary glands and wax-secreting glands of the ear canal, probably developed from this type of gland. sweat gland sweat gland sweat gland Read more