• Which is the only organ of your body not fully developed at the time of birth?
• Do males also lactate (produce milk)?
• What is meant by witch’s milk?

There are organs of the body which mark gender inequality from biological perspective, such as a mammary gland. A mammary gland is a medical term for your breast. Mammals get their name from the presence of and the mammary gland function. The Latin word “mamma” literally means “breast”. Here you will learn about mammary glands function in males and females with labelled diagram.

Just like salivary, sweat, sebaceous and mucous glands, it is an exocrine gland. It produces and releases milk onto the external body surface through a duct for feeding the young offspring.

Lactation, breastfeeding and nursing are the similar terms used for the process of producing milk and feeding it to newborn infants.

While males and females both possess the breasts, there are marked differences between the two in terms of their growth, development, size and roles in the sexual and parental life. In rare cases, the mammary glands are absent in the individual, a condition called amastia.

Mammary Glands Function in Males and Females:

The mammary glands function in males and females is quite easy to understand. Though they may produce milk (at least witch’s milk) in both the genders, the breasts play a more significant role in the sexual and parental life of female humans. For example, lactation allows the females to breastfeed the young offspring.

What is Witch’s Milk?

Did you know newborn babies often release milk from their own breasts? The neonatal milk is colloquially known as witch’s milk. Usually, considered a normal physiological occurrence, the neonatal milk secretion can occur in both the male and female infants. So, there is no need of testing or treatment.

Occurring in about 5 percent of newborns, witch’s milk production can persist into childhood. Apart from being a natural physiological phenomenon, certain medications can also trigger the secretion of witch’s milk.

Structural Perspective:

There are a variety of tissue and cell types in the mammary gland. It is one of the few tissues in your body that can repeatedly experience functional differentiation, growth and regression. This is one of the factors behind the great interest in the study of these glands.

A cross-section of this organ shows the structures like nipple, milk duct, fatty tissue, lobules, areola, pectoralis muscles, chest wall, and skin. Here the nipple is the raised region of the tissue on the surface of the breast, which houses an opening for the milk duct. Forming a branching system, the laciferous ducts serve as a connecting link between the nipple and the lobules. Areola refers to the pigmented area surrounding the nipple on the breast.

Stages of Development:

Joan Huber (2015) in his book On the Origins of Gender Inequality, describes three phases of growth that the mammary gland undergoes. The first one occurs in the uterus before birth; the second one is witnessed during the childhood when the gland keeps pace with the physical growth; and the third one is completed during the pubertal period.

The fifth week of the embryonic life marks the development of the paired breasts of adult females from a line of glandular tissue in the foetus, called the milk lines. In the sixth week, the development of mammary glands occurs without hormonal stimulation.

The placental sex hormones enter the blood circulatory system of foetus after 28 weeks of gestation. Near term, the mammary ducts (numbering about 15 to 25) form the foetal mammary gland which is composed of the glandular tissue, protective fatty tissue, and the supporting connective tissue.

The breasts of both the female and male newborn infants commonly swell and release a small amount of so-called witch’s milk immediately after the birth. The infant’s mammary glands are stimulated by the same hormones that the placenta secretes to prepare the mother’s breasts for lactation.

The glands stop releasing witch’s milk within 3 to 4 weeks followed by the long period of inactivity until shortly before the onset of puberty when hormones again stimulate growth.

As a female gets 10 to 12 years old, the tree-like network of ducts extends into a branching system. Within 2 years of the onset of menses, the alveolar buds are formed, and new buds keep sprouting for years to come, thereby producing alveolar lobes. As a female reaches puberty, her breasts grow to adult size.