Mammary Gland Anatomy
Overview
The mammary gland, commonly known as the breast, is a modified apocrine sweat gland
located in the superficial fascia of the pectoral region. It is present in both sexes but remains
rudimentary in males, developing more fully in females at puberty. Its primary function in females
is to provide milk to newborns. Enlargement of male breasts is called gynecomastia.
Location and Extent
Located in the superficial fascia of the pectoral region.
A small extension, the axillary tail of Spence, pierces the deep fascia and extends into the
axilla.
The passage through which the axillary tail passes is called the foramen of Langer.
The axillary tail is a common site for breast tumors.
Shape: Hemispherical bulge.
Vertical extent: 2nd to 6th rib.
Horizontal extent: Lateral border of the sternum to the mid-axillary line.
Relations
Deep aspect related to:
Pectoral fascia
Muscles: Pectoralis major, serratus anterior, and external oblique.
Retromammary space: A space filled with loose areolar tissue separating the breast from the
pectoral fascia, allowing for mobility.
Structure
The breast consists of three main structures:
Skin
Stroma
Parenchyma (glandular tissue/mammary gland proper)
Skin
Nipple: Conical projection, usually at the level of the 4th intercostal space. Contains smooth
muscle fibers for erection and is highly sensitive due to rich innervation.
Areola: Circular pigmented area surrounding the nipple. Contains modified sebaceous glands
that secrete lubricating oil. Darkens and enlarges during pregnancy. Enlarged sebaceous
glands during pregnancy are called Montgomery's tubercles.
Overview
The mammary gland, commonly known as the breast, is a modified apocrine sweat gland
located in the superficial fascia of the pectoral region. It is present in both sexes but remains
rudimentary in males, developing more fully in females at puberty. Its primary function in females
is to provide milk to newborns. Enlargement of male breasts is called gynecomastia.
Location and Extent
Located in the superficial fascia of the pectoral region.
A small extension, the axillary tail of Spence, pierces the deep fascia and extends into the
axilla.
The passage through which the axillary tail passes is called the foramen of Langer.
The axillary tail is a common site for breast tumors.
Shape: Hemispherical bulge.
Vertical extent: 2nd to 6th rib.
Horizontal extent: Lateral border of the sternum to the mid-axillary line.
Relations
Deep aspect related to:
Pectoral fascia
Muscles: Pectoralis major, serratus anterior, and external oblique.
Retromammary space: A space filled with loose areolar tissue separating the breast from the
pectoral fascia, allowing for mobility.
Structure
The breast consists of three main structures:
Skin
Stroma
Parenchyma (glandular tissue/mammary gland proper)
Skin
Nipple: Conical projection, usually at the level of the 4th intercostal space. Contains smooth
muscle fibers for erection and is highly sensitive due to rich innervation.
Areola: Circular pigmented area surrounding the nipple. Contains modified sebaceous glands
that secrete lubricating oil. Darkens and enlarges during pregnancy. Enlarged sebaceous
glands during pregnancy are called Montgomery's tubercles.
