Breast Histology Flashcards
Where is the breast in relation to the body wall?
Outside the body wall; not in the body wall
It’s a subcutaneous gland
Approx how many lobes make up the secretory tissue of the breast?
15-25 lobes
What type of gland is found in the lobes of the breasts?
Each lobe consists of a
compound tubulo-acinar gland
which drains via a series of ducts leading to the nipple
What type of connective tissue surrounds the secretory lobules?
Dense fibrous tissue
which in turn is surrounded by adipose
Between which two structures do suspensory ligaments of the breast extend?
from the dermis of the skin
to the deep fascia overlying the muscle of the anterior chest wall
Where are the suspensory ligaments most pronounced?
What is their role thought to be?
Often most pronounced in the upper breast
Thought to support the breast tissue
What is clinically relevant about the suspensory ligaments of the breast?
because when breast becomes oedematous or inflamed
there’s essentially nowhere for excess pressure to go (because all essentially surrounded by connective tissue)
which will change surface of breast as a result and clinically will see changes on surface of breast
What is the basic functional secretory unit of the breast?
The Terminal Duct Lobular Unit (TDLU)
Explain the route of the non-lactating breast from the terminal ductules
Terminal ductules –> intralobular collecting duct –> lactiferous duct for that lobe –> nipple –> passes through lactiferous sinus (an expanded duct region near the nipple)
What kind of epithelial cells line the acini?
Cuboidal
and columnar
Describe myoepithelial cells
The secretory cells of the acinus are surrounded my myoepithelail cells
They are contractile epithelial cells wich in turn are surrounded by the basal lamina
Which cells surround the secretory cells of the acinus?
Myoepithelial cells
Which cells line the lactiferous duct?
The lacteriferous ducts are lined by an epithelium that varies from a thin stratified squamous to stratified cuboidal
What cells cover the nipple?
A thin highly pigmented keratinsed stratified squamous epithelium
What is the core of the nipple made up of?
dense irregular connective tissue mixed with bundles of smooth muscle
Regarding the lactiferous duct where do you find stratified sq. epithelium and where do you find stratified cuboidal epithelium?
As the duct approaches the surfaces it becomes lined by stratified squamous epithelium,
however deeper it is lined by stratified cuboidal epithelium
(see image a)
What happens to mammary glands during the luteal phase of the menstrual cycle?
The epithelial cells increase in height
the lumina of the ducts becomes enlarged
and small amounts of secretions appear in the ducts
What changes happen to the mammary gland in the first trimester of pregnancy?
elongation and branching of the smaller ducts
proliferation of the epithelial cells of the glands and the myoepithelial cells
What changes happen in the mammary gland in the second trimester?
glandular tissue continues to develop with differentiation of secretory alveoli
plasma cells (produces IgA; important for colustrum) and lymphocytes infiltrate the nearby connective tissue
What changes happen in the mammary gland in the third trimester of pregnancy?
alveoli continue to mature
development of extensive rER
What changes happen over the three trimesters of pregnancy?
Reduction in amount of connective tissue
Reduction in amount of adipose tissue present
Which hormones stimulate proliferation of secretory tissue?
Oestrogen
Progesterone
What is human milk composed of?
88% water
1.5% protein (mainly lactalbumin and casein)
7% carbohydrate (mainly lactose)
3.5% lipid
with small quantities of ions, vitamins and IgA antibodies
“Different components of milk are secreted via different mechanisms”
T/F
True
Different components of milk ARE secreted via different mechanisms
