breast Flashcards
structure of the breast
mammary glands are modified sweat glands - in superficial facia anterior to the pectoral muscles and anterior thoracic wall
mammary glands made of ducts and secretory lobules -> 20 lactiferous ducts - open independently onto nipple
connective tissue surround duct and lobules - condenses to form ligaments - continuous with the dermis of the skin and support the breast
describe nipple
surrounded by a circular pigmented area of skin - aerola
effect of carcinoma on the ligaments
creates tension - pitting
main components in breast in non-lactating women
fat
main components in breast in lactating women
glandular tissue
relations of the breast
lie on deep fascia
connective tissue - retromammary space separates the breast from deep fascia - provides degree of movement
base of breast
rib 2-6 to mid axillary line
arterial supply of the breast
laterally - axilliary artery: superior thoracic, thoracoacromial, lateral thoracic and subscapular
medially - branch of internal thoracic artery
second to 4th IC artery via branches that perforate thoracic wall and overlying muscle
venous drainage of the breast
parallel arteries
eventually drain into axillary, internal thoracic and inter-costal veins
innervation of the breast
anterior and lateral cutaneous branches of 2nd and 6thh IC nerves
nipple - innervated by the 4th IC nerve
lymphatic drainage of the breasr
75% - laterally and superiorly to the axillary nodes
parasternal nodes - deep to anterior thoracic wall and associated with internal thoracic artery
vessels that follow the lateral branches of the posterior intercostal arteries - connect with intercostal nodes situated near the head and the neck of the ribs
drainage of axillary nodes
subclavian trunks
drainage of the parasternal nodes
bronchiomediastinal trunks
intercostal nodes drainage
thoracic duct or broncomediastinal trunks
breast in men
rudimentary
small ducts
composed of cords of cells
don’t extend beyond the areola
where does breast cancer occur
cells in acini, lactiferous ducts and lobules of the breast
how do breast tumours spread
lymph
veins
direct invasion
what is peau d’orange
lymph blockage and tumour pull on ligaments = orange peel texture
what is cancer en cuirasse
manifestation = hard woody texture
Anatomy of breast
under hormonal influence
modified sweat gland
15-20 ductal globular units - drain into main duct
fat interspersed
divided by fibrous septae that radiate from centre outwards - suspensory ligaments of cooper
made of glandular tissue, fat and fibrous tissue
from 2nd - 6th rib space
breast parenchyma extends into anterior axillary fold a axillary tail of spence
upper half of breast contains the most breast tissue
complex network behind the nipple
4-18 ducts open on summit of nipple/areola
coopers ligament
connective tissue strands connect anterior and posterior fascial planes
supporting structure
provides shape and consistency of parenchyma
cooper’s droop
blood supply of breast
branch of lateral thoracic artery, internal thoracic artery, thoracoacromial artery, thoracodorsal artery and intercostal arteries
skin supplied by subdermal plexus - communicates with deep parenchymal vessels
nipple areola - receive branch from internal thoracic artery
dominant blood supply form medial aspect
venous drainage of the breast
3 groups veins: perforating branches of internal mammory vein, tributaries of auxillary vein, perforating branch of posterior intercostal veins
in continuity with Batson plexus of veins - posterior
conduit for dissemination of breast cancer to spine, pelvis and elsewhere
innervation of the breast
anterolateral and anteromedial branches of thoracic intercostal nerves T3-6
innervation from supraclavicular nerves to upper and lateral parts of breast
nipple - dominant supply from lateral cutaneous branch of T4
lymphatic drainage of the breast
predominant lymph supply in the axilla
lymph nodes arranges like a square based pyramid - pectoral, subscapular, humeral, central, apical
pyramid contain cutanius nerve, motor nerve, artery and vein
some lymph drain into interpectoral, deltopectoral, supraclavicular or deep cervical
75% drain into lymphatics in axilla
25% into internal mammary node
thoracic nerve
damage causes winging of the scapular
supplies serratus anterior
thoracodorsal pedical
nerve runs down with artery and vein
damage causes paralysis of latissimus dorsi
