Mammary Gland Med Reviewer.docx

MAMMARY GLAND  produce & secrete nutritive milk  located at the level of the 2nd rib to 6th rib bet. the sternum & axillary lines Mode of secretion: highly modified apocrine sweat glands Morphology: Compound tubuloalveolar glands  15-25 lobes – separated by DICT with adipose tissue  Cooper’s Ligament – suspensory ligament; maintain the shape & support of the mammary gland  parenchyma consists of only duct elements LE of ducts: simple cuboidal epithelium  Intralobular tissue – loose vascular CT  Interlobular tissue – DICT – reticular arrangement;  beyond the area of the ductal system (+) adipose cells RESTING / INACTIVE  Terminal Duct – Lobular Units (TDLU) *sparse (relatively apart & undeveloped)  lobules that comprise the mammary gland lobe (+) terminal duct / intralobular duct (+) acini (+) intralobular connective tissue Connective and adipose tissue are greatly diminished Duct proliferate and continuously branch LE: simple columnar epithelium Alveoli develop and start to dilate due to milk secretion ACTIVE / PREGNANT STATE  colostrum – eosinophilic substance; first milk (+) IgA antibodies Stellate myoepthilial cells Plasma cells, lymphocytes and eosinophils increase in number in the surrounding stroma of the ducts  abundant milk  distended acini fill up the whole breast tissue LACTATING BREAST  CT is reduced  thin septa (-) adipose tissue NIPPLE Also known as mammillary papilla Cylindrical or conical eminence in the anterior chest (4th ICS) Areola – area at the base of the nipple Epidermis Lined with stratified squamous keratinizing epithelium  Dense CT long and vascular dermal papilla – (+) Meissner’s corpuscles  Smooth muscles arranged longitudinally and radially (+) Sebaceous glands / Montgomery Glands / Areolar glands  Function: Lubricates and protects the nipple Dermis  Lactiferous Duct LE: Simple cuboidal epithelium with myoepithelial cells  Lactiferous Sinus LE: Stratified cuboidal epithelium, underneath the areola