Endocrine glands and temporary endocrine glands:

Endocrine glands are specialized glands that secrete hormones into the bloodstream. These hormones regulate various physiological functions in the body, including growth and development, metabolism, and reproduction. Some of the major endocrine glands in humans include the pituitary gland, thyroid gland, adrenal gland, pancreas, and ovaries/testes.

Temporary endocrine glands are glands that form during pregnancy and are only present for a short period of time. These glands play a crucial role in the development and maintenance of the pregnancy.

Placenta as a temporary endocrine gland:

The placenta is a temporary endocrine gland that forms during pregnancy. It is a specialized organ that develops in the uterus and provides nutrients and oxygen to the developing fetus. The placenta also plays a crucial role in the production of hormones that regulate various physiological functions during pregnancy.

Some of the hormones produced by the placenta include:

- Human chorionic gonadotropin (hCG): This hormone is produced by the placenta soon after conception and is responsible for maintaining the corpus luteum (a structure that forms in the ovary after ovulation). The corpus luteum produces progesterone, which is essential for maintaining the pregnancy.
- Estrogen and progesterone: These hormones are produced by the placenta and are responsible for maintaining the pregnancy and preparing the body for childbirth.
- Human placental lactogen (hPL): This hormone is produced by the placenta and is thought to be involved in regulating glucose metabolism in the mother and promoting the growth and development of the fetus.

In summary, the placenta is a temporary endocrine gland that plays a crucial role in the development and maintenance of pregnancy. It produces hormones that regulate various physiological functions in the body, including maintaining the pregnancy and preparing the body for childbirth.

Formation of corpus luteum during menstrual cycle and formation of placenta during pregnancy occur to release hormones.