Microscopic anatomy

The breast is composed of glandular elements, fibrous and fat tissues. The glandular part of the breast consists of between 15 and 20 lobes. A lobe has approximately 30 lobules, which terminate in the acini (10-100). The acini are separated from each other by the intralobular connective tissue and the lobules are separated from each other by fine connective tissue. Light microscopic examination of an acinus demonstrates that it is composed of two cell types: the secretory epithelial cell and the contractile myoepithelial cell. The terminal duct and the acini of a lobule are termed the 'terminal duct lobular unit'. These ducts unite to form subsegmental and segmental ducts, which in turn drain into the lactiferous ducts and sinuses. The lactiferous ducts (15-20) pass towards the nipple and areola, where they undergo dilatation to form the

Axillary artery

Thoracodorsal nerve

Medial cutaneous nerve

Median nerve

Axillary artery

Thoracodorsal nerve

Medial cutaneous nerve

Median nerve

Lateral thoracic artery

Intercostobrachial nerve

Long thoracic nerve

Subscapular artery

Circumflex scapular artery

Thoraco-acromial artery

Ulnar nerve

Subscapular artery

Circumflex scapular artery

Lateral thoracic artery

Intercostobrachial nerve

Long thoracic nerve

Figure 17.3. Lymphatic drainage of the breast. Permission from Essential Clinical Anatomy, Williams & Wilkins, Baltimore.

Figure 17.4. Microscopic anatomy of the breast. Permission from Atlas of Human Histology, di Fiore MSH (ed.), Lea and Febiger, Philadelphia, p. 245.

lactiferous sinuses. The sinuses open onto the surface of the nipple through separate ductular orifices (Fig. 17.4).

0 0

Post a comment