II. Anatomy

  1. GynBreastAnatomyGeneral.jpg
  2. GynBreastAnatomyLobes.gif
  3. GynBreastAnatomyLobules.gif
  4. gynBreastLobuleGrayBB1172.gif Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)

III. Anatomy: Surrounding landmarks

  1. Underlying foundation to Breast tissue
    1. Pectoralis major Muscle
    2. Serratus anterior border (laterally, inferior)
  2. Lateral border
    1. Latissimus dorsi Muscle (axilla)
  3. Inferior Breast border
    1. Inframammary ridge
  4. Superior Breast border
    1. Second rib (inferior to clavicle)
  5. Medial Breast border
    1. Sternum

IV. Anatomy: Organization

  1. Structural Components
    1. Peri-Nipple structures
      1. Areola
      2. Areolar glands
      3. Nipple
    2. Cooper's Ligaments
      1. Add structure to Breast
      2. Attached to underlying fascia
  2. Key Lactation Components: Ducts and Lobules
    1. Lobules
      1. Composed of acini and ducts
    2. Lobes
      1. Composed of Lobules
    3. Lactiferous ducts
      1. Drain lobes to ducts at nipple surface (6-10 major ducts drain to surface)

V. Physiology: Development

  1. Pre-Puberty
    1. Breasts in resting state
    2. Nonfunctional ducts
  2. Puberty: Stage 1 Mammogenesis
    1. Ovulation starts
      1. Menstrual Cycle related increase in Estrogen and Progesterone
    2. Ducts elongate due to Estrogen
    3. Type 1 Breast lobules develop
    4. Breast alveolar buds form
      1. Appear as retroareolar mass (Do not excise as mass! - halts Breast development)
    5. Type 2 and 3 Breast lobules form from the alveolar buds
      1. Side branches of ducts and lobular elements form
  3. Maturity (end of Puberty)
    1. Further Breast development stops at the end of Puberty (until pregnancy)
    2. Breasts become pendulous
    3. Lobular elements well formed in resting state
  4. Pregnancy
    1. General Changes
      1. Areolar pigmentation
      2. Vascular engorgement
        1. Mammary Blood Flow increases 180%
        2. Breast doubles in weight
        3. May result in bloody Nipple Discharge
          1. Second and third trimester and early Lactation
          2. Resolves spontaneously in most cases
    2. Stage 2 Mammogenesis (first half of pregnancy)
      1. Breast alveoli develop in response to increased Estrogen and Progesterone levels
      2. Proximal ducts grow and branch
      3. Type 3 Breast lobules form in response to HCG in early pregnancy
        1. Breast lobulesn as well as the overall Breast increase in size during pregnancy
    3. Stage 1 Lactogenesis or Secretory Initiation (second half of pregnancy)
      1. Increased Progesterone from the placenta inhibits Prolactin and milk production
      2. Small amounts of milk and colostrum form
    4. Stage 2 Lactogenesis or Secretory Activation (after delivery)
      1. Progesterone levels fall (without placenta)
        1. Proalctin is no longer inhibited by Progesterone, and Lactation occurs
      2. Prolactin
        1. Stimulates copious milk production
        2. Prolactin secretion is inhibited by Dopamine activity at D2 receptors on the Hypothalamus
      3. Other Lactation triggers
        1. Cortisol
        2. Insulin
        3. Nipple stimulation
        4. Emptying of the Breast (by Breast Feeding or pumping)
      4. Oxytocin
        1. Stimulates milk let down, myoepithelial cell contraction and milk ejection
  5. Perimenopausal
    1. Lobules begin to recede
    2. Leaves residual ducts and fibro-connective tissue
    3. Breast cysts commonly develop during this stage
  6. Postmenopausal
    1. Residual ducts and fat
    2. Easiest time for Clinical Breast Exam

VI. References

  1. Pillay (2022) Lactation Physiology, Stat Pearls, Treasure Island, Fl, accessed 2/24/2023
    1. https://www.ncbi.nlm.nih.gov/books/NBK499981/

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Related Studies

Ontology: Breast (C0006141)

Definition (FMA) Region of pectoral part of chest which has as its parts nipple, areola, breast proper.
Definition (MSHCZE) Párový orgán na přední straně hrudníku - u lidí. Skládá se z mléčných žláz, kůže, svalů, z tukové a pojivové tkáně.
Definition (UWDA) Subdivision of the pectoral part of the chest which consists of the nipple, areola and breast proper.
Definition (NCI_NCI-GLOSS) Having to do with the breast.
Definition (NCI_NCI-GLOSS) Glandular organ located on the chest. The breast is made up of connective tissue, fat, and breast tissue that contains the glands that can make milk.
Definition (NCI) One of two hemispheric projections of variable size situated in the subcutaneous layer over the pectoralis major muscle on either side of the chest.
Definition (NCI_CDISC) One of two hemispheric projections of variable size situated in the subcutaneous layer over the pectoralis major muscle on either side of the chest. (NCI)
Definition (MSH) In humans, one of the paired regions in the anterior portion of the THORAX. The breasts consist of the MAMMARY GLANDS, the SKIN, the MUSCLES, the ADIPOSE TISSUE, and the CONNECTIVE TISSUES.
Concepts Body Part, Organ, or Organ Component (T023)
MSH D001940
SnomedCT 272669003, 361079003, 76752008
HL7 BRST
LNC LP29849-4, LP7086-4, MTHU001046, MTHU011382, LA4255-1
English Breast, Mammary, Breasts, Mammary region, Mammary part of chest, Mamma, breast structure, mamma, breasts, breast, Breast anatomy (body structure), BREAST, mammary, Breast structure, Breast anatomy, Breast structure (body structure), Breast, NOS
French Seins, Sein, Région mammaire
Swedish Bröst
Czech prsy
Finnish Nisä
Russian GRUDNAIA ZHELEZA, MOLOCHNAIA ZHELEZA, ZHELEZA MOLOCHNAIA, ГРУДНАЯ ЖЕЛЕЗА, ЖЕЛЕЗА МОЛОЧНАЯ, МОЛОЧНАЯ ЖЕЛЕЗА
Croatian DOJKA
Polish Pierś, Gruczoł mleczny, Sutek, Piersi, Gruczoł piersiowy
Norwegian Bryst
Spanish anatomía mamaria (estructura corporal), anatomía mamaria, Seno, estructura de la mama (estructura corporal), estructura de la mama, mama, seno, Mama
Portuguese Seio, Corpo Mamário, Mama
German Brust, Brustdrüsen
Italian Mammella
Dutch Borst, Mamma

Ontology: Breast Diseases (C0006145)

Definition (MSHCZE) Patologické procesy probíhající v prsou.
Definition (MEDLINEPLUS)

Most women experience breast changes at some time. Your age, hormone levels, and medicines you take may cause lumps, bumps, and discharges (fluids that are not breast milk).

If you have a breast lump, pain, discharge or skin irritation, see your health care provider. Minor and serious breast problems have similar symptoms. Although many women fear cancer, most breast problems are not cancer.

Some common breast changes are

  • Fibrocystic breast changes - lumpiness, thickening and swelling, often just before a woman's period
  • Cysts - fluid-filled lumps
  • Fibroadenomas - solid, round, rubbery lumps that move easily when pushed, occurring most in younger women
  • Intraductal papillomas - growths similar to warts near the nipple
  • Blocked milk ducts
  • Milk production when a woman is not breastfeeding

NIH: National Cancer Institute

Definition (NCI) A non-neoplastic or neoplastic disorder that affects the breast. Representative examples of non-neoplastic disorders include fibrocystic disease, gynecomastia, and mastitis. Representative examples of neoplastic disorders include fibroadenoma, lobular neoplasia, carcinoma, lymphoma, and sarcoma.
Definition (MSH) Pathological processes of the BREAST.
Definition (CSP) disease or disorder of the breast.
Concepts Disease or Syndrome (T047)
MSH D001941
ICD9 610-612.99, 611.9
ICD10 N60-N64.9 , N64.9, N60-N65
SnomedCT 79604008, 198129001, 198566004, 155962003, 155946009, 266647006, 155966000
English Diseases, Breast, Unspecified breast disorder, Disorders of breast, mammary disorder, Disease, Breast, Breast disorders NOS, Disorder of breast, unspecified, BREAST DIS, Disease of breast, breast disorders, breast disorders (diagnosis), DISORDERS OF BREAST, Breast disorder NOS, Breast disorders, Breast Diseases [Disease/Finding], Breast Diseases, breast disease, disease of breast, breast diseases, diseases of the breast, breast disorder, diseases of breast, Disorders of breast (N60-N65), Breast disorders NOS (disorder), Breast--Diseases, Mastopathy, Breast disorder, Breast disease, mastopathy, Disease of breast, NOS, Disorder of breast, NOS, Disorder of breast, Disease of breast (disorder), Disorder of breast (disorder), Breast Disease, Breast Disorder
Italian Patologia della mammella, Patologie della mammella, Disturbi non specificati del seno, Patologia della mammella NAS, Mastopatia, Malattie della mammella
Dutch niet-gespecificeerde borstaandoening, borstaandoening NAO, mastopathie, Aandoening van mamma, niet gespecificeerd, borstaandoeningen, borstaandoening, Aandoening van de borst, Aandoeningen van de borst
French Affection mammaire SAI, Trouble du sein non précisé, Mastopathie, Affection mammaire, Affections du sein, Maladies du sein, Mastopathies
German unspezifische Brusterkrankung, Affektion der Brustdruese NNB, Krankheit der Mamma, nicht naeher bezeichnet, Mastopathie, Affektionen der Brustdruese, Erkrankung der Brust, Brustkrankheiten
Portuguese Afecção mamária NE, Mastopatia, Afecção mamária, Afecções da mama, Doenças Mamárias
Spanish Trastorno mamario NEOM, Trastorno no especificado de la mama, enfermedad de la mama (trastorno), enfermedad del seno, Mastopatía, trastornos mamarios, SAI, trastornos mamarios, SAI (trastorno), Breast disorders NOS, enfermedad mamaria, Trastornos mamarios, Trastorno mamario, trastorno de la mama (trastorno), trastorno de la mama, enfermedad de la mama, Enfermedades de la Mama
Japanese 乳房障害, 詳細不明の乳房障害, 乳房異常, 乳房障害NOS, ニュウボウショウガイ, ショウサイフメイノニュウボウショウガイ, ニュウボウショウガイNOS, ニュウボウイジョウ, 乳房疾患, 乳腺症, ニュウセンショウ
Swedish Bröstsjukdomar
Czech senologie, Poruchy prsu, Porucha prsu NOS, Blíže neurčená porucha prsu, Porucha prsu, Mastopatie, nemoci prsů, prsy - nemoci
Finnish Nisän sairaudet
Russian MOLOCHNOI ZHELEZY BOLEZNI, МОЛОЧНОЙ ЖЕЛЕЗЫ БОЛЕЗНИ
Korean 상세불명의 유방 장애
Croatian DOJKA, BOLESTI
Polish Choroby piersi, Choroby sutka, Choroby gruczołu piersiowego
Hungarian Emlő betegségek, Emlő betegség k.m.n., Emlő betegség, Nem meghatározott emlőbetegség, mastopathia
Norwegian Brystsykdommer