Anatomy 7 - Breast Anatomy and Histology Flashcards
What types of tissue are present in the breast?
Secretory
Adipose
Dense fibrous
What type of glands are the mammary glands very similar to?
Sweat glands
What makes up the mammary glands?
Series of ducts and 15-25 secretory lobules
What makes up each lobule?
A compound tubulo-acinar gland (i.e. multiple branches serve a single lobule)
How does the mammary gland drain?
Each alveoli in the lobule is drained by one lactiferous duct
The ducts converge at the nipple
What is the connective tissue stroma (that surrounds the breast) made of?
Fibrous tissue
Fatty tissue
What does the fibrous stroma converge to form?
Suspensory ligaments of Cooper
What is the function of the suspensory ligaments of Cooper?
Attach breasts to dermis and pectoral fascia
Separate the secretory lobules of the breast
What does the base of the breast lie on?
Pectoral fascia
Where is the retromammary space?
Between the breast and pectoral fascia
What is the lactiferous sinus?
Expanded duct region that connects lactiferous duct to the nipple
What type of lining epithelium is present in larger ducts?
Columnar
What type of epithelium is present in the secretory epithelium?
Cuboidal or low columnar
What are myoepithelial cells?
Contractile cells that ‘squeeze’ out milk from secretory cells into the duct
Where are the myoepithelial cells found?
Between the secretory cells and the basement membrane
What type of epithelium covers the nipple?
Highly pigmented keratinised squamous epithelium
What types of tissue make up the nipple?
Dense irregular connective tissue (fibrocollagenous) mixed with bundles of smooth muscle
What type of epithelium lines the duct as it approaches the surface of the breast?
Stratified squamous
What type of epithelium lines the duct deep to the surface of the breast?
Stratified columnar
What is the difference between sebaceous glands on the breast vs sebaceous glands on the skin?
Breast - glands end directly on skin
Skin - oil follows hair follicle
What changes occur in the mammary gland during the luteal phase of menstrual cycle?
Epithelial cells increase in height
Lumina of ducts enlarge
Small secretions in ducts
What changes occur in the mammary gland during the first trimester of pregnancy?
Elongation and branching of small ducts
Proliferation - epithelial cells and myoepithelial cells
What changes occur in the mammary gland during the second trimester of pregnancy?
Glandular tissue developing
Differentiation of secretory alveoli
Plasma cells and lymphocytes infiltrate nearby connective tissue
What changes occur in the mammary gland during the third trimester of pregnancy?
Secretory alveoli continue to mature
Development of rER
Overall, what are the changes in the amounts of tissue during pregnancy?
Reduction - connective and adipose
Increase - secretory
What hormones stimulate the proliferation of adipose tissue during pregnancy?
Oestrogen
Progesterone
What is the composition of human milk?
88% water 1.5% protein 3.5% lipid 7% carbohydrate Ions Vitamins IgA
What are the 2 proteins mainly found in milk?
Lactalbumin
Casein
What is the main carbohydrate found in milk?
Lactose
How is the fat component of milk secreted?
Apocrine secretion
What is apocrine secretion?
Secretions are ‘budded’ off, surrounded by membrane and carrying cytoplasm
How is the protein component of milk secreted?
Merocrine secretion
What is merocrine secretion?
Proteins made in rER
Secreted when vesicles merge with apical membrane
What happens to the secretory cells of the breast during menopause?
Secretory cells degenerate
Leaving only ducts
What happens to the connective tissue of the breast during menopause?
Fewer fibroblasts
Reduced collagen and connective fibres
