Breast Anatomy Flashcards
What are breasts?#
What are they made up of?
Modified and highly specialised sweat glands that are depndent on hormones. They experience physiological changes with age and pregnancy
They are comprised of glandular epithelial tissue made up of ducts and lobules as well as mesenchymal fat and fibrous tissues
Describe the ultrastructure of breasts?
Each breast has 8-10 lobules arranged like the petals of a flower. inside each lobe are many smaller structures called lobules. At the end of each lobule are tiny sacs(bulbs) that can produce milk
What are the boundaries of the breasts
They extend from the 2nd or 3rd rib down to the 6th rib.
They range from the sternal edge to the mid-axillary line.
How are breasts related to the chest wall
2/3rds lie upon the deep pectoral fascia.
1/3rd lie upon fascia covering the serratus anterior
They are all anchored to the dermis by the suspension ligament of Cooper
Explain the anatomy of the breast
Nipple+ Areola –> lactiferous duct–> parenchyma
Describe the structure of the nipple
Contains no fat or hair
Contains collagenous dense connective tissue, elastic fibres and bands of smooth muscle
The tips of the nipples are fissured with lactiferous ducts
Describe the structure of the Areola
The areola is the skin around the nipple
Contains multiple sweat and sebacious glands
Produce oily lubricant to provide protection to the nipple and areola
How is the breast divided?
4 quadrants:
Upper lateral quadrant- superolateral quadrant- contains axillary tail
Upper medial quadrant- superomedial quadrant
Lower lateral quadrant- inferolateral quadrant
Lower medial quadrant- inferomedial quadrant
What is the breast like in males?
When does the breast change in males?
Rudimentary. It is formed by two small duct without lobules or alveoli. There is little supporting fibroadipose tissue.
There is temporary enlargment in the newborn and during puberty
How do the breast develop?
Mammary crests develop during the 4th week of gestation. These breast extend from the axillary region to the inguinal region.
Primary mammary buds become secondary buds which become lactiferous ducts which branch
What are the breasts supplied by?
Name some of the major branches
Iliary artery, internal thoracic artery and some intercostal arteries.
Thoracoacromial artery- branch of axillary artery
Lateral thoracic artery- more posterior branch of axilla
Internal mammary (thoracic artery)- branch of subclavian
What innervates the breast?
The anterior and lateral cutaneous branches of the 4-6th intercostal nerves convey sensing fibres to the skin of the breast. They also carry sympathetic fibres or the blood vessels to the smooth muscle around the breast
How do the breast drain lymphatically
75% of the breasts lymphatic drainage in the lateral quadrants goes into the axillary lymph nodes. Some lymphs may drain directly into the supraclavicular or inferior cervical nodes. Lymphs from medial quarters drain to the parasternal or to the opposite breast
Describe the soft tissue of the breast?
Made up of lobes which contain a network of glandular tissue consisting of branching ducts and secretory lobules in a connective tissue stroma.
The terminal duct lobular unit is the functional milk secretory component of the breast
Describe the connective tissue of the breast
The connective tissue stroma that surrounds the lobules is a dense and fibrocollagenous whereas the intra lobular tissue has a loose texture
