Anatomy of the Breast power point presentation.pptx

breast

1. THE ANATOMY OF THE BREAST Presentor . Taremwa Moses SHO-1 Facilitator. Dr. Lois Asiimwe 11th/10/2022

2. Outline. Embryology development. Age changes Extension and attachment Structures Blood supply Lymphatic drainage Clinical importance.

3. Embryology. The mammary gland is an epidermal appendage. Derived from the apocrine gland. The Ectoderm – responsible for the formation of the ducts and alveoli. Develops from the ectoderm during the 2 nd month of pregnancy. The Ectoderm form 2 milk lines extending from the Axilla to the groin. One of the upper part of the milk line persists and form the mammary gland. The mesenchyme – responsible for the connective tissue and the vessels.

4. Age Changes in the Breast. Before puberty. It is rudimentary, only the tip of the nipple is raised The male and female breast are the same. At puberty. Becomes rounded due to fat deposition. Buds appear and the breast and nipple are raised. The areola also gets larger. During Pregnancy and lactation. The breast is large and tense, with glandular breast tissue present. At menopause , the breast becomes smaller due to loss of fat.

5. Functions of the Breast It is part of reproductive system Respond to sexual stimulation Breastfeeding Modified apocrine sweat glands apex of cell becomes part of secretion and breaks off

6. Anatomy of the Breast. Position and Attachment 1. Upwards: to the 2 nd rib 2. Downward: to the 6 th rib.Lateral 3. Medially: to the margin of the sternum. 4. Laterally: midaxillary line. 5. Axillary tail: an extension of the gland that enters the Axilla 6. Surrounded by superficial fascia 7. Rest on deep fascia

7. Positioning and attachment The breast lies on top of the pectoralis major muscle (2/3) and lower 1/3 on top of serratus anterior muscle. Fixed to underlying fascia of the skin and the two basal muscles by fibrous Connective tissue bands Cooper’s (Suspensory) Ligaments Note. Ligaments may retract when breast tumors are present. Left breast is usually slightly larger Base is circular, either flattened or concave Separated from pectoralis major muscle by fascia, retro mammary space Spaces around the lobules and ducts are filled with fat, ligaments and connective tissue

8. The breast.

9. The attachment, retromammary space.

10. Structure. Outer surface convex, skin covered Nipple : a . At 4 th intercostal space except for multiparous mother b . Small conical/cylindrical prominence below the centre . Is s urrounded by areola: circular pigmented ring of skin around the nipple. Thin skinned region lacking hair, sweat glands Contains areolar glands

11. Areola: contains dark pigment that intensifies with pregnancy a. Circular and radial smooth muscle fibers b. Cause nipple to raise

12. Cont. Each breast consists of 15 - 20 lobes of secretory tissue a. Each lobe has one lactiferous duct b. Lobes (and ducts) arranged radially c. Embedded in connective tissue & adipose of superficial fascia d. Lobes composed of lobules e. Lobules comprise alveoli

13. Excretory (lactiferous) ducts converge toward areola Lobules and ducts Each breast has a number of sections (lobules) that branch out from the nipple. Each lobule holds tiny, hollow sacs (alveoli). The lobules are linked by a network of thin tubes (ducts). If you're breast-feeding, ducts carry milk from the alveoli toward the dark area of skin in the center of the breast (areola). From the areola, the ducts join together into larger ducts ending at the nipple.

14. Secretory epithelium. Changes with hormonal signals, Female breast tissue is sensitive to cyclic changes in hormone levels b. Onset of menstruation c. Pregnancy (glands begin to enlarge at 2nd month) d. After birth, 1st secretion is colostrum (contain antibodies)

15. “Tail of Spence” = axillary tail a. prolongation of upper, outer quadrant in axillary direction b. Passes under axillary fascia c. May be mistaken for axillary lymph nodes Fatty Tissue: surrounds surface, fills spaces between lobes a. Determines form & size of breast b. No fatty deposit under nipple & areola

16. Vessels and Nerves Blood supply. (PPPL) 1. Arteries: derived from thoracic branches of three pairs of arteries Pectoral branch of the thoracoacromial branch Perforating branches of the internal thoracic artery Perforating branches of the intercostal artery Lateral thoracic artery, a branch from axillary artery.

17. Venous drainage. Internal thoracic vein drain in the brachiocephalic vein Intercostal veins drain in the internal thoracic, azygos and hemiazygos veins Lateral thoracic vein to the axillary vein.

18. Nerve supply. Sensory innervation is derived from the branches of intercostal nerves T3 – T5. Others; lower cervical plexus Sensation of the nipple is derived from the lateral cutaneous branch of T4.

19. Lymphatics: The lymphatic system is a network of lymph nodes and lymph ducts that helps fight infection .

20. Routes for Metastasis From medial lymphatics to parasternal nodes Then to mediastinal nodes Across the sternum in lymphatics to opposite side via cross-mammary pathways Then to contralateral breast From subdiaphragmatic lymphatics to nodes in abdomen Then to liver, ovaries, peritoneum

21. Clinical significance. The breast is susceptible to many benign and malignant disorders Puerperal mastitis Mastalgia Fibrocystic breast changes Fat necrosis Breast abscess Galactorrhea

22. Tumours and Cysts b. Breast Cyst 1. Benign 2. May be aspirated if large

23. Fibrocystic breast changes 1 ) 20%+ of premenopausal women 2 ) Cyst can cause discomfort 3 ) treatment rarely required 4 ) More likely to not detect a developing cancer

24. Intraductal papilloma M ay produce “chocolate” or bloody discharge from nipple Lipoma: common fatty tumors in the breast

25. Carcinoma of the Breast Most common malignant tumor among women. Apprx . 1/8 women will develop breast cancer, generally there is no discomfort. Physical signs: a . Slowly growing, painless mass b . May demonstrate retracted nipple c . May be bleeding from nipple d . May be distorted areola, or breast contour e . Skin dimpling in more advanced stages with retraction of Cooper’s ligaments

26. Progression of Breast cancer

27. . Common sites for metastasis a. Lungs & pleura b. Skeleton system (skull, vertebral column, pelvis) c. Liver . Atypical carcinomas a. Inflammatory carcinoma (hormonal, chemotherapy) b. Paget’s disease of the breast

28. Surgical intervantions . Mammectomy Ductal carcinoma in situ (DCIS) Stages I & II Stage III after chemotherapy Lumpectomy