Brs Chapter 7 - X Female Reproduction

The correct answer to this question requires a visual representation or diagram that outlines the complex pathway for producing progesterone and estrogen, making it difficult to explain in text form. The incorrect answers provided do not accurately depict the biological processes involved in the production of these hormones.

The correct answer explains how the hypothalamus communicates with the anterior pituitary to trigger the release of key hormones involved in regulating ovarian function.

FSH and LH play a crucial role in the functioning of the ovaries by promoting steroidogenesis, follicular development, ovulation, and luteinization. Therefore, options 1, 2, and 3 are incorrect as they do not relate to the actions of FSH and LH in the ovaries.

Estrogen has various important functions in the female reproductive system and beyond, including those mentioned in the correct answer. It does not increase testosterone levels, inhibit female secondary sex characteristics, or reduce osteoporosis risk.

Progesterone plays a crucial role in maintaining pregnancy and the secretory activity of the uterus, as well as exerting negative feedback on FSH and LH secretion. It does not stimulate follicle development or promote uterine contractions during pregnancy; in fact, it raises the uterine threshold to contractile stimuli.

The menstrual cycle consists of four main phases: Follicular phase, Ovulation, Luteal phase, and Menses, with each phase having specific days in the cycle. It is important to understand the chronological order of these phases to track the menstrual cycle accurately.

Primordial follicles develop into graafian follicles during the follicular phase of the menstrual cycle, not during the luteal phase, ovulation, or menstruation. The other incorrect answers do not accurately reflect the development process of primordial follicles.

During the follicular phase of the menstrual cycle, progesterone levels are low as the corpus luteum has not yet been formed to produce progesterone.

Elevated estradiol exerts a negative feedback effect on the anterior pituitary, leading to suppression of FSH and LH levels.

Ovulation is triggered by a surge in luteinizing hormone (LH), which typically occurs around 14 days before the start of the next menstrual period. Therefore, ovulation occurs on day 14 of the menstrual cycle, regardless of the total length of the cycle.

The correct answer explains the role of estradiol in positively influencing the secretion of FSH and LH, leading to the LH surge.

Ovulation is a complex process in the menstrual cycle where the release of an egg from the ovary is triggered by a surge of luteinizing hormone (LH), which is induced by high levels of estrogen. The other incorrect options do not accurately reflect the hormonal mechanisms that directly lead to ovulation.

Estrogen levels decrease right after ovulation due to the decline in follicle-stimulating hormone (FSH) levels. However, they increase during the luteal phase under the influence of luteinizing hormone (LH) and progesterone.

During ovulation, changes in cervical mucus occur to create a more optimal environment for sperm to travel through the reproductive tract. The increase in quantity and change in consistency help facilitate the journey of sperm to meet the egg for fertilization.

The corpus luteum develops during the luteal phase of the menstrual cycle and its main function is to synthesize and release estrogen and progesterone to prepare the uterus for potential implantation of a fertilized egg.

During the luteal phase, the endometrium increases in vascularity and secretory activity to prepare for potential implantation of a fertilized egg. The incorrect answers do not accurately represent the changes that occur in the endometrium during this phase.

During the luteal phase, increased levels of progesterone have a thermogenic effect on the hypothalamic thermoregulatory center, leading to an increase in basal body temperature.

The corpus luteum regresses at the end of the luteal phase if fertilization does not occur, leading to a decrease in estradiol and progesterone levels. The incorrect answers do not directly cause regression of the corpus luteum as described in the correct answer.

Estrogen and progesterone levels rise steadily throughout pregnancy to support fetal development and maintain the pregnancy.

Estrogen and progesterone play crucial roles in preparing the body for pregnancy and supporting fetal development. The correct answer highlights their effects on the endometrium, ovarian follicular function, and breast development. The incorrect answers do not align with the known effects of these hormones during pregnancy.

When fertilization occurs, the developing embryo produces human chorionic gonadotropin (hCG) which signals the corpus luteum to continue producing progesterone to maintain the uterine lining for pregnancy. The corpus luteum is not allowed to regress and plays a crucial role in supporting early pregnancy.

HCG, or Human Chorionic Gonadotropin, is a hormone produced by the placenta during pregnancy. It is commonly used in pregnancy tests to detect early signs of pregnancy.

HCG levels peak around week 9 of pregnancy before starting to decline. It is an important hormone produced during pregnancy.

During the first trimester of pregnancy, the corpus luteum (a temporary endocrine structure in the ovaries) is responsible for producing estradiol and progesterone, which are vital hormones for maintaining pregnancy. The corpus luteum is stimulated by Human Chorionic Gonadotropin (HCG), a hormone produced by the developing placenta. While the placenta eventually takes over hormone production later in pregnancy, during the first trimester, the corpus luteum plays a crucial role in hormone production.

Progesterone is primarily produced by the corpus luteum in the ovaries during the first trimester, but once the placenta is fully developed, it becomes the main source of progesterone production during the second and third trimesters.

During the second and third trimesters, estrogens are primarily produced by the interplay of the fetal adrenal gland and the placenta as the correct answer states.

Estriol is the major placental estrogen produced during pregnancy, providing various important functions for both the fetus and the mother.

During pregnancy, progesterone plays a key role in maintaining the uterine environment by increasing the threshold for uterine contractile stimuli. Estrogen also has important functions during pregnancy but does not have the same effect on uterine contractility as progesterone. GnRH is a hormone released by the hypothalamus that regulates the release of other hormones, and oxytocin is responsible for stimulating uterine contractions during labor.