Breast Anatomy and Physiology
what are the margins of the breast?
lies anterior to and courses along the pectoral muscle. Its margins can reach the clavicle superiorly, the latissimus dorsi muscle laterally, and the sternum medially; it extends into the axilla
hormone responsible for lobular proliferation and growth
progesterone
triangulation
render the quadrant and approximate clock time of the abnormality
A layer of adipose tissue and connective fascia that separates the breast from the pectoral muscle and allows breast motion over the chest wall
retromammary fat space
scientific term for all of the tissue on the breast that is not part of the parenchyma
stroma
the presence of one or more "extra" nipples that might be present on a person's body
supernumerary nipple *accessory nipples*
a small gland that secretes sweat, situated in the dermis of the skin
sweat gland
the intralobular terminal ducts end at the?
terminal ductules, numbering anywhere from 10 to 100 in any lobule
Four named quadrants that describe location in the breast
• Upper outer quadrant • Upper inner quadrant • Lower inner quadrant • Lower outer quadrant
when the breast increases in size during pregnancy or by weight gain then weight loss..what happens to cooper's ligament
Cooper's droop *ligaments that maintain the position of the mammary glands against the chest, are stretched and gradually lose strength*
fibrous membranes supportive structures of the breast that incompletely sheathe, but support the lobes of the breast
Cooper's ligaments.
what separates the breast from the pectoral muscle?
A layer of adipose [fat] tissue and connective fascia [ fibrous tissue enclosing a muscle or other organ]
area of skin that is darker than the rest of your breast skin
Areola
specialized sebaceous type glands providing lubrication during lactation
Montgomery's glands *Sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals*
Small bumps on the areola may be?
Montgomery's glands or hair follicles.
elevations formed by the openings of the ducts of the Montgomery glands located near the periphery of the areola
Morgagni tubercles aka Montgomery tubercles
hormone present only during initial breast growth, pregnancy, and lactation
Prolactin
what occupies the skin of the body of the breast?
Sweat glands, sebaceous (oil) glands, and hair follicles that open to form pores
most types of breast cancer, arises from the
TDLU
an extension of breast tissue that extends into the axilla
Tail of Spence or axillary tail
Extending from the nipple orifice, the duct starts as a collecting duct that immediately widens into the lactiferous sinus (ampulla), a pouch-like structure that again narrows as it joins one or more segmental ducts
lactiferous sinus (ampulla)
the pouch-like structure that narrows as it joins one or more segmental ducts
lactiferous sinus (ampulla-a flasklike dilatation of a tubular structure)
what does the extralobular stroma hold?
larger ductal structures
external landmarks of the breast
nipple, inframammary fold, and axilla
resting breast means
no pregnancy or lactation
Because the pattern and distribution of the glandular tissue is essentially the same bilaterally. The tissue from one breast will __________ the opposite breast with minor variations
"mirror"
breast parenchyma include
- milk ducts and the glands that produce the milk *glandular tissues* -Lymphatic network
margins of the breast
-anterior to and along the pectoral muscle -can reach the clavicle superiorly, the latissimus dorsi muscle laterally, and the sternum medially; it extends into the axilla
copper's ligaments attach where and travels where?
-base of the breast -extend outward, -attaching to the anterior superficial fascia of the ski
where is the skin thickest and thinnest of the breast?
-thickest at base -thinnest at nipple
the functional unit of the breast
20-40 terminal ductal lobular units (TDLU)
common location for accessory nipples
6:00 o'clock position near or below the inframammary fold
the place where the breast and the chest meet
Inframammary fold *IMF* {6th or7th rib}
a band of fatty tissue apparent posterior to the glandular island in most women
Retroglandular fat space
a small gland in the skin which secretes a lubricating oily matter (sebum) into the hair follicles to lubricate the skin and hair
Sebaceous gland
ducts that join together like branches of grape stems, gradually forming into larger ducts.
Small milk ducts are attached to the lobules
2 layers of breast fascia
Superficial layer (superficial fascia) within the premammary layer. Deep layer (deep fascia) lies posterior to the mammary layer within the retromammary space
what lines the lumen [inside space] of the ducts and smaller ductal structures
Two layers of epithelial cells *changes that take place in the breast mostly occur here*
where does the breast lie along the pectoralis major muscle?
anterior
The outer layer that lines the lumen [inside space] of the ducts and smaller ductal structures
basement membrane
shapes of the nipple
flat, inverted or prominent
The _______ layer of breast fascia sits immediately on top of the pectoralis muscle, and the_________ layer sits just under the skin
deep superficial
hormone responsible for ductal proliferation [rapid reproduction of a cell]
estrogen
two most prominent hormones active in breast physiology
estrogen progesterone
Other tissues that give the breast structures support are?
extralobular and intralobular stroma
small duct just outside and leading to the lobule
extralobular terminal duct
connective tissue that surrounds all mammary tissues and separates the breast into superficial and deep tissues
fascia
include ligaments, supportive tissues (stroma), and scar tissues and can become more prominent than the fatty tissues in an area of the breast, possibly resulting in a firm or rubbery bump
fibrous tissue
which direction does the pectoralis major muscle lie?
in an oblique line from the humerus to midsternum
what happens to the TDLU during life cycle changes, menstrual cycle, and hormone fluctuation
increases and decreases in number and size
what is a specialized tissue that gives the lobule its shape and definition
intralobular stroma *this extensive capillary network allows the exchange of hormones into and secretions out of the lobule and is in close contact with the lymphatic system which also provides for transmission of cancer cells to the lymphatic network and blood stream
the extralobular terminal duct divides into the?
intralobular terminal ducts
Adult women have 15-20 _______ in each breast
lobes
the minute (1 to 2 mm) portion of the duct that holds the milk-producing elements of the breast
lobule
Each lobe has 20-40 ________
lobules
the breast is called a
mammary gland
what is the TDLU [terminal ductal lobular unit] responsible for?
milk production and hormonal and nutritional exchange
a type of smooth muscle that contracts the acini [functional epithelial cells that produce milk] and ducts to empty these structures of milk produced during lactation
myoepithelium
the layer beneath the epithelial layer?
myoepithelium
There are about 10 duct systems in each breast, each with its own opening at the ________
nipple
center part of the breast at the apex
nipple
Atrophy [wasting away] of glandular tissue begins medially and posteriorly, working its way to the________
nipple *"new" tissue or growth of tissue in these areas in an aging woman may signal the presence of malignancy*
the crevices on the nipple are called
orifices *collecting ducts*
Abnormal growth and change in the breast are partially due to
over- or underproduction of hormones
location of the base of the breast
portion adjacent to the chest wall
The 15 to 20 lobes extend from the nipple in a radial pattern allowing normal milk flow. What might be indicated if the flow looks changed
possible pathology
location of the apex of the breast
the nipple
all the cells of that area that have an essential function.
the parenchyma of an body part
function of collecting ducts
transfer milk from the lactiferous ducts