Tag: parturition and lactation

• Mammary glands or breasts are modified sweat glands that lie over the pectoral muscles. Each breast has a broad multiporous tip called nipple for the release of milk. A circular pigmented area called areola lies below it. Each breast contains 15-20 glandular lobes separated from one another by dense connective tissue and adipose tissue. Each lobe is further made of many lobules having glandular or secretory alveoli.

Parturition is the act of expelling the full-term young one from the mother's uterus at the end of gestation. Gestation (pregnancy) is completed in about 266 days from the mother's last menstruation.

The mammary glands of the female undergo differentiation after the pregnancy and starts producing milk towards the end of it, called lactation and the milk produced during these initial few days is referred to as colostrum. This contains many antibodies that is essential for the new born babies to develop resistance against any pathogen attack or disease. During oogenesis the gamete mother cell undergoes meiosis division to form the primary oocyte and this further divides into the secondary oocyte and a polar body by means of an unequal division. 

 Prolactin hormone is secreted by pituitary gland it stimulates the secretion of milk from mammals. It rises only when a baby suckles. Hormone oxytocin cause tiny muscles around the alveoli to squeeze the milk by using small tubes called milk ducts. Oxytocin is also responsible for contraction of uterus muscles, during and after birth. Prolactiiin and Oxytocin help the mother to form an emotional bond with her baby. Progesterone regulates the growth in size of alveoli and lobes. Estrogen stimulates the milk duct system to grow. Follicle stimulating hormone, luteinizing hormone and human chorionic gonadotropin control the level of estrogen and progesterone production.    

Parturition, also called birth or childbirth, process of bringing forth a child from the uterus, or womb. The prior development of the child in the uterus is described in the article human embryology. The process and series of changes that take place in a woman’s organs and tissues as a result of the developing fetus are discussed in the article pregnancy. Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully-developed foetus and the placenta which requires the release of oxytocin from the posterior lobe of the maternal pituitary.

After ovulation the lining of the (graafian) follicles grow inward, forming corpus luteum (yellow body), which temporary function as endocrine tissue. It secrete estrogen and progesterone, which stops additional ovulation, and thickening of uterine wall. If pregnancy does not occur within 14 days corpus luteum degenerates and menstruation follows.

Gestation (pregnancy) is completed in about 266 days from the mother's last menstruation. The gestation period of human beings is 270 days to 280 (approximately). It is usually about 266 days i.e., 36 weeks.

Parturition can be defined as the act of expelling the full term young ones from the mother's uterus at the end of the gestation period. In other words, the process of delivery of the fetus is known as parturition.