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Ch. 28 Pregnancy and Human Development
Marieb - Human Anatomy & Physiology 11th Edition
Marieb, Hoehn11th EditionHuman Anatomy & PhysiologyISBN: 9780136874034당신이 사용하는 게 아니라요?교과서 변경
28장, 문제 16

The life span of the ovarian corpus luteum is extended for nearly three months after implantation, but otherwise it deteriorates.
(a) Explain why this is so.
(b) Explain why it is important that the corpus luteum remain functional following implantation.

검증된 단계별 안내
1
Step 1: Understand the role of the corpus luteum before and after implantation. The corpus luteum forms from the ruptured follicle after ovulation and secretes progesterone, which is crucial for maintaining the uterine lining for potential pregnancy.
Step 2: For part (a), explain that the corpus luteum normally deteriorates after about 10-14 days if fertilization does not occur, due to the absence of luteinizing hormone (LH) support. However, after implantation, the developing embryo produces human chorionic gonadotropin (hCG), which signals the corpus luteum to continue functioning and producing progesterone, thus extending its lifespan for nearly three months.
Step 3: For part (b), clarify that the continued function of the corpus luteum is important because progesterone maintains the thickened endometrium, preventing menstruation and creating a supportive environment for the developing embryo and placenta during the early stages of pregnancy.
Step 4: Emphasize that without the corpus luteum's progesterone production post-implantation, the uterine lining would break down, leading to miscarriage or failure of the pregnancy to establish.
Step 5: Summarize that the corpus luteum's extended lifespan is hormonally regulated by hCG from the embryo, and its function is critical to sustaining the early pregnancy until the placenta can take over hormone production.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Corpus Luteum Function and Lifespan

The corpus luteum is a temporary endocrine structure in the ovary that forms after ovulation. It produces progesterone, which is essential for maintaining the uterine lining. Normally, it degenerates after about 14 days if pregnancy does not occur, but its lifespan is extended during early pregnancy to support gestation.
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가이드 코스
06:04
Functional Groups

Role of Human Chorionic Gonadotropin (hCG)

After implantation, the developing embryo secretes hCG, a hormone that signals the corpus luteum to continue producing progesterone. This hormone prevents the corpus luteum from deteriorating, thereby sustaining the uterine environment necessary for embryo development during the first trimester.
추천 영상:
1:04
Implantation Example 2

Importance of Progesterone in Early Pregnancy

Progesterone maintains the thickened endometrium, preventing menstruation and creating a supportive environment for the embryo. Its continued production by the corpus luteum is crucial until the placenta takes over hormone production, ensuring the embryo's survival and proper development.
추천 영상:
0:49
Early Embryonic Development Example 1