[W5] The breast Flashcards
Where is the breast located on the thoracic wall?
On the anterior thoracic wall, horizontally from the lateral border of the sternum to the mid-axillary line, and vertically from the 2nd to the 6th costal cartilages.
What muscles lie deep to the breast?
Pectoralis major and serratus anterior.
What are the two main regions of the breast?
The circular body and the axillary tail (tail of Spence).
What is the axillary tail?
A smaller part of the breast that runs along the inferior lateral edge of pectoralis major towards the axillary fossa.
What is the function of the mammary glands?
Milk production to nourish infants.
Are the breasts usually symmetric?
No, the left breast is usually larger than the right.
Do males have functioning breasts?
No, males have rudimentary, non-functioning breast tissue.
What is the nipple made of and what exits from it?
Erectile tissue; 15–20 lactiferous ducts exit through it.
What is the areola and what are Montgomery’s tubercles?
Pigmented skin around the nipple; Montgomery’s tubercles are sebaceous glands that lubricate the nipple during lactation.
What is the connective tissue stroma?
A fibrous and fatty supporting structure around the mammary glands.
What do the fibrous components of the stroma form?
Suspensory ligaments of Cooper.
Functions of suspensory ligaments?
- Attach breast to dermis and pectoral fascia
- Separate secretory lobules
What is the pectoral fascia?
A connective tissue sheet beneath the breast attached to pectoralis major.
What is the retromammary space and its significance?
A loose connective tissue space between breast and pectoral fascia; used in reconstructive surgery.
Which arteries supply the breast?
- Branches from axillary
- Internal mammary
- Intercostal arteries
Describe venous drainage of the breast.
Via anastomotic circle around nipple, draining into axillary and mammary veins.
Main route for lymphatic drainage?
Axillary lymph nodes.
General somatic nerve supply?
T4–T6 thoracic nerves; relay sensation and trigger milk ejection reflex.
Sympathetic innervation role?
T2–T6; motor to nipple arousal, response to cold.
Is there parasympathetic innervation of the breast?
No.
What is thelarche?
The onset of breast development, typically around age 9 (range 8–13 years).
What is the usual sequence of pubertal signs?
Usually thelarche before pubarche, though it can vary.
Is asymmetry common in pubertal breast development?
Yes, and it usually resolves by age 16–18.
Describe Tanner Stage 1.
Preadolescent; elevation of papilla only.
