Mind map

BREAST

Joud Alrashoud English

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BREAST

BLOOD SUPPLY
- Branches of axillary artery
  - supply lateral part
    - Superior thoracic
    - Thoracoacromial
    - Lateral Thoracic
    - Subscapular
- Perforating branches from internal thoracic artery
  - Supply medial part
- Mammary branches of Post.Intercostal arteries (3rd-5th)
Female breast
- structure
  - skin
    - Nipple: conical projection of the ant surface of breast
      - site
        opposite 4th intercostal space
      - carries 15-20 narrow pores of lactiferous ducts
    - Areola: pigmented circular area of skin surrounding base of nipple
      - Areolar glands/ Glands of Montogomery
      - Montogomery tubercles
        produced by the underlying areolar glands
  - glandular tissue
    - mammary gland: modified sweat gland
      - site
        superficial fascia ant to perctoralis major ms and its fascia
      - components
        parenchyma
        15-20 pyramidal lobes
        each lobe
        drained by lactiferous ducts
        lactiferous ducts dilate to form lactiferous sinus near areola
        each lactiferous duct opens separately on the summit of nipple
        radiate out from the nipple
        fibrous stroma
        ligaments of cooper: anchor parenchyma to the overlying skin
        fatty stroma
        main bulk of the breast
        give the rounded contour of the breast
        absent beneath the nipple & areola
  - connective tissue
- shape
  - conical/hemispherical
- site
  - deep fascia related to pectoralis major ms
- extension
  - base extends from 2-6 ribs & from to sternum medially to midaxillary line laterally
- parts
  - Apex
  - Tail
    - Axillary tail (of Spence): 95% of females
      - project from the upper & outer quadrant of breast
      - pierce deep fascia at lower border of pectoralis major
      - enter axilla through foramen of langer
  - Base
    - upper 2/3: Pectoralis major and its fascia
    - lower 1/3: Serratus ant & External oblique
HISTOLOGY
- Birth > pre-pubertal
  - lactiferous ducts without alveoli
- Puberty
  - Branching of duct
    - solid spherical masses (precursor of alveoli)
- Pregnancy
  - mammary glands
    - proliferation of secretory alveoli at the end of interlobular ducts
    - spherically dilated alveoli
      - cuboidal epithelium
      - stellate myoepithelium cells
        between
        secretory cells
        basal lamina
    - reduction in inter and intra lobular CT
- During lactation
  - Marked reduction in interlobular tissue
  - Marked reduction in intralobular CT
  - Markedly distended acini (alveoli)
    - prolactin
      - milk production
  - Epithelial cells of alveoli enlarge
    - synthesize
      - protein
      - lipid
- After lactation
  - glandular tissue return to resting condition
    - NON-PREGNANT MAMMARY GLAND
      - Stroma
        Interlobar septa
        thick fibrous CT (cooper lig)
        interlobular septa
        Adiopose CT
        Interlobular
        loose vascular CT
        lymphatics
        plasama cells
        macrophages
      - Parenchyma
        lobe
        Terminal duct lobular units
        lactiferous ducts
        proximal part
        lined with
        low/moderate estrogen levels
        cuboidal epithelium
        covered with
        myoepithelial cells
        peak estrogen
        columnar epithelium
        around ovulation in premenstrual phase of the cycle
        Terminal part
VENOUS DRAINAGE
- circular venous plexus
  - Axillary vein
    - >
      - Subclavian vein
  - Internal thoracic vein
    - >
      - Brachiocephalic vein
  - Intercostal veins
    - >
      - right: Azygos vein
      - left: Hemizygos vein
LYMPHATIC
- lymph vessels
  - Superficial
    - Subareolar plexus
  - Deep
    - Submammary plexus
      - lymph nodes
        Central & lateral part of gland
        Upper part of gland
        axillary lymph node
        subclavian trunks
        Medial part of gland
        internal thoracic (parasternal) lymph nodes
        Inferomedial (lower)
        Lymphatic of rectus sheath
        linea alba
        subdiaphragmatic
        axillary tail
        subscapular axillary lymph nodes
        posterior intercostal arteries
        posterior intercostal lymph nodes
        thoracic duct
        bronchomediastinal trunks