Biology · Ch 2 — Reproduction in Lower and Higher Animals
Mammary Glands
Mammary Glands
Mammary glands : Accessory organs of the female reproductive system, responsible for producing and releasing milk after parturition. They develop at puberty under the influence of estrogen and progesterone, and lactotropic hormone (LTH, or prolactin) helps develop the lactiferous tubules during pregnancy itself.
The mammary glands are a pair of rounded structures situated in the subcutaneous tissue of the anterior thorax, in the pectoral region (roughly from the second to the sixth rib); they are, in fact, modified sweat glands. Each gland contains fatty connective tissue together with numerous lactiferous ducts, and its glandular tissue is divided into 15–20 irregularly shaped mammary lobes, each with its own alveolar glands and lactiferous duct. The alveolar glands secrete milk, which is stored in the lumen of the alveoli; the alveoli open into mammary tubules, whose ducts join within each lobe to form a mammary duct. Many mammary ducts in turn join to form a wider mammary ampulla, connected to the lactiferous duct; these ducts converge towards the nipple, near the tip of the breast, which is surrounded by a dark, circular patch of skin called the areola.
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your textbook's own diagram.
What this figure shows. A vertical section through the breast: the gland lobules with their alveoli, the ducts uniting into the lactiferous duct and widening into the lactiferous sinus behind the nipple, the fat and suspensory ligaments packing the gland, and beneath it the pectoralis major muscle, the intercostal muscles and the ribs over …
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Breast cancer :
Symptoms : the first symptom is usually a painless lump in the breast or underarm; swelling of all or part of the breast, skin irritation, breast or nipple pain, nipple retraction, redness, scaliness or thickening of the nipple or breast skin, discharge. …