system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
The breast is a hormonally responsive organ. Which statement about progesterone is NOT true?
assistant
The correct answer is  Progesterone is produced by the ovary and by the placenta and stimulates growth of the acini and lobules. Progesterone also causes an increase in interstitial fluid in the breast, paicularly in the perilobular stroma. During pregnancy, progesterone from the placenta stimulates marked increases in the lobules, both in size and number, and is responsible for secretory modifications in the cytoplasm of the acinar cells. Estrogen promotes fat deposition and growth of both stroma and the duct system of the breast. Ref: Molina P.E. (2013). Chapter 9. Female Reproductive System. In P.E. Molina (Ed), Endocrine Physiology, 4e.