Week 7- breast week Flashcards
What makes up the secretory tissue of the breast?
15-25 lobes, which each consist of tubule-acinar glands which drain via a series of ducts to the nipple.
What is directly next to the secretory lobules?
What is adjacent to this?
Deep fibrous tissue.
Adipose tissue is then next to this.
What are suspensory ligaments made of?
Condensed fibrous tissue.
Where do the suspensory ligaments in the breast run from?
The dermis of the skin to the deep fascia overlying the muscles on the anterior chest wall.
What is a basic functional secretory unit of the breast?
Terminal duct lobular unit.
In the non-lactating breast, where do the terminal ducts lead?
Into an intralobular collecting duct which leads into the lactiferous duct for that lobe.
Where are the lactiferous ducts?
What is the name for the expanded area in the lactiferous duct.
They lead to the nipples. First it goes through an area of expanded duct called the lactiferous sinus before reaching the nipple.
What is another word for terminal ductal lobular unit?
Acini
Describe the drainage of the breast through the ductal system?
All lobules contain several terminal ductal lobular units. These (also known as acini) drain too the intralobular collecting system, then the extra lobular collecting system and then into the lactiferous duct. The lactiferous duct then enlarges to form the lactiferous sinus and then exits via the nipple.
What lines the acini (terminal ductal lobular unit)?
Secretory epithelial cells. They vary from columnar to cuboidal.
What surrounds the secretory cells of the acini?
What is the function of this cell?
Myoepithelial cells.
They are contractile epithelial cells which in turn are surrounded by basal lamina.
What lines larger ducts (e.g.lactiferous duct)
The epithelium varies from thin stratified squamous to stratified cuboidal.
Also myoepithelial cells are present.
What are mammary glands said to be like?
Sweat glands that are slightly modified.
What covers the surface of the nipple?
Stratified squamous keratinised epithelium.
What makes up the core of the nipple?
Dense connective tissue (fibrocollagenous) mixed with bundles of smooth muscle.
What ducts are present within the nipple?
Lactiferous ducts.
Describe the change in lining of the lactiferous duct from deep to superficial?
Deep- it will be stratified cuboidal epithelium
Nearer the surface- stratified squamous epithelium.
What other glands can be found in the nipple?
Sebaceous glands.
What occurs during the luteal phase of menstruation to the glands in the nipple?
Epithelial cells increase in height.
The lumina of the ducts becomes enlarged
Small amounts of secretion in the ducts.
If pregnancy occurs, what changes take place to the breasts?
Elongation and branching of the smaller ducts.
Proliferation of cells of the glands and myoepithelial cells
In the second trimester- glandular tissue continues to develop with differentiation of secretory alveoli
Plasma and lymphocytes infiltrate into the connective tissue.
In the third trimester alveoli continue to mature, with development of extensive RER.
Also a reduction in connective tissue and adipose tissue.
During pregnancy, what does oestrogen and progesterone stimulate?
Proliferation of secretory tissue and fibro-fatty tissue becomes sparse.
What is the composition of human milk?
88% water
1.5% protein
7% carbs
3.5% lipid
With small quantities of ions, vitamins and IgA antibodies.
What is an apocrine secretion?
Lipid droplets surrounded by membrane and carrying a small amount of cytoplasm.
Where are the proteins in milk made?
What sort of secretion is this?
RER. Packaged in the Golgi body and secreted via vesicles which merge with the apical membrane to release contents into the duct system.
Merocrine secretion.