Breast development and anatomy
Up until the onset of puberty, the breasts are much the same in the male and female and their internal structure is similar – a collection of ducts emptying into the nipple.
During puberty in the female, the tissue of the breast responds to the release of female sex hormones estrogen and progesterone. These stimulate the formation of additional ducts and a system of milk secreting glands. There is also an increase in volume and elasticity of connective tissue, deposition of adipose tissue and increased vascularity.
Until the menopause, the woman’s breast tissue will continue to respond to the changing hormonal environment that follows the menstrual cycle. The breast spends the majority of its life in a ‘resting’ state, fulfilling its physiological function, lactation, under the control of hormonal changes that accompany pregnancy and childbirth.
The breast is made up of the secretory glandular tissue and surrounding adipose tissue (Figure 1). The glandular tissue comprises between 15 and 20 lobes with varying numbers of ducts and lobules surrounded by connective tissue.
Each lobe connects to a lactiferous duct, several of which converge to form a lactiferous sinus or milk chamber. These sinuses empty into the nipple where there are a number of duct openings.
The nipple is surrounded by a pigmented area, the areola, which is lubricated by secretions from the sebaceous glands.
Beneath the tissues of the breast lie the muscles of the chest wall (pectoralis major and minor), and between the two is a layer of connective tissue known as the fascia. Two layers of fibrous ligaments (Cooper’s ligaments) support the mammary gland and hold the breast against the chest.
Figure 1. Anatomy of the breast
During puberty in the female, the tissue of the breast responds to the release of female sex hormones estrogen and progesterone. These stimulate the formation of additional ducts and a system of milk secreting glands. There is also an increase in volume and elasticity of connective tissue, deposition of adipose tissue and increased vascularity.
Until the menopause, the woman’s breast tissue will continue to respond to the changing hormonal environment that follows the menstrual cycle. The breast spends the majority of its life in a ‘resting’ state, fulfilling its physiological function, lactation, under the control of hormonal changes that accompany pregnancy and childbirth.
The breast is made up of the secretory glandular tissue and surrounding adipose tissue (Figure 1). The glandular tissue comprises between 15 and 20 lobes with varying numbers of ducts and lobules surrounded by connective tissue.
Each lobe connects to a lactiferous duct, several of which converge to form a lactiferous sinus or milk chamber. These sinuses empty into the nipple where there are a number of duct openings.
The nipple is surrounded by a pigmented area, the areola, which is lubricated by secretions from the sebaceous glands.
Beneath the tissues of the breast lie the muscles of the chest wall (pectoralis major and minor), and between the two is a layer of connective tissue known as the fascia. Two layers of fibrous ligaments (Cooper’s ligaments) support the mammary gland and hold the breast against the chest.
Figure 1. Anatomy of the breast
