Lab 1 - Module 1: Pectoral Region - Page 3 of 5

Breast and Mammary Glands

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The female breast is situated on the anterior surface of the thorax, overlying the pectoral muscles. The mammary glands are accessory organs of the female reproductive system, located within the breasts. The amount of fat surrounding the glands determines the size of the breast. The breasts are usually described with the upper limb because they must be removed during dissection to study the pectoral muscles. Male mammary glands are normally rudimentary; therefore, the following describes the female breasts.

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Identify the following structures using the diagram to help you locate the structures. Check off each of the following:

Areolae - The circular areas of skin around the nipples are called areolae.

Lactiferous ducts - Lactiferous ducts give rise to lobules of glandular tissue (mammary glands). Each lobule is drained by a lactiferous duct, each of which opens on the nipple.

Lactiferous sinus - The lactiferous ducts extend from the nipple like spokes of a wheel. Under the areola each duct has a dilated portion, called the lactiferous sinus, in which milk accumulates during lactation.

Suspensory (Cooper) ligaments - The mammary gland is situated within the superficial fascia. The mammary gland is firmly attached to the skin of the breast by suspensory (Cooper) ligaments; these bands support the breast.

At puberty the lactiferous ducts undergo branching and thereafter progressive enlargement of the breasts occurs.