Reproductive cycle graph-Follicular phase | NCLEX-RN | Khan Academy

Summary

This video explains the intricate hormonal changes that occur in the female reproductive cycle, focusing on the ovarian cycle. It details how hormones like Estrogen, Progesterone, and Inhibin interact with the body, affecting follicle development and the uterine cycle. Using a graph, the video breaks down the Follicular Phase, ovulation, and hormone fluctuations, illustrating the roles of gonadotropic hormones (FSH and LH) and their feedback mechanisms. The cycle is mapped out, showing how these hormonal interactions lead to ovulation and prepare the body for potential fertilization.

Takeaways

• 😀 Female eggs develop in the ovaries, triggering fluctuations in sex hormones such as Estrogen, Progesterone, and Inhibin.
• 😀 The Ovarian Cycle Graph is a helpful tool for understanding the hormonal changes in the female body throughout the reproductive cycle.
• 😀 The reproductive cycle is split into two main phases: the Follicular Phase and the Luteal Phase.
• 😀 Gonadotrophic hormones, FSH and LH, are released from the anterior pituitary and regulate follicle development in the ovaries.
• 😀 Estrogen levels rise as follicles grow and granulosa cells secrete Estrogen, influencing the endometrium of the uterus.
• 😀 The Proliferative Phase occurs in the uterus, where a new layer of endometrium is formed in response to increasing Estrogen levels.
• 😀 High Estrogen levels lead to a reduction in FSH and LH release from the brain, a negative feedback mechanism.
• 😀 Granulosa cells also secrete Progesterone and Inhibin, which inhibit FSH release and further control hormone levels.
• 😀 A paradoxical surge in LH occurs when Estrogen levels reach a very high level, triggering the Luteal Surge.
• 😀 The Luteal Surge, driven by high LH levels, leads to ovulation, where the egg is released from the follicle on day 14 of the cycle.
• 😀 The process of ovulation is a key event at the midpoint of the menstrual cycle, transitioning from the Follicular Phase to the Luteal Phase.

Q & A

What hormones are released from the ovaries during the development of eggs?

The hormones released from the ovaries during the development of eggs are Estrogen, Progesterone, and Inhibin.

What is the Ovarian Cycle Graph, and why is it useful?

The Ovarian Cycle Graph is a tool used to understand and visualize the events of the female reproductive cycle. It shows the fluctuations of hormones over a 28-day cycle, helping to track the stages of the ovarian and uterine cycles.

What do the axes of the Ovarian Cycle Graph represent?

The x-axis represents time, which is a 28-day cycle, and the y-axis represents various hormone levels (such as FSH, LH, Estrogen, Progesterone, and Inhibin) as well as stages of the Uterine Cycle.

What are the two main phases of the reproductive cycle, and how are they characterized?

The two main phases of the reproductive cycle are the Follicular Phase and the Luteal Phase. The Follicular Phase involves the development of the follicles and increased Estrogen production, while the Luteal Phase occurs after ovulation and involves the preparation of the uterus for potential implantation.

What is the role of FSH and LH in the Ovarian Cycle?

FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone) are released by the anterior pituitary gland to stimulate the development of follicles in the ovaries. FSH promotes the growth of follicles, while LH triggers ovulation.

How does Estrogen affect the development of the endometrium during the Follicular Phase?

As Estrogen levels rise during the Follicular Phase, they stimulate the proliferation of the endometrium, leading to the formation of a new layer of endometrial tissue after menstruation.

What is the role of Inhibin in the ovarian cycle?

Inhibin is produced by granulosa cells in the growing follicles, and its primary role is to inhibit the release of FSH from the anterior pituitary gland, thus regulating follicle development.

Why do FSH and LH levels decrease as Estrogen levels increase?

When Estrogen levels are high, the brain senses this and reduces the release of FSH and LH through negative feedback, as high Estrogen levels indicate sufficient follicle development.

What happens when Estrogen levels reach a very high point during the cycle?

When Estrogen levels reach a very high point, it triggers a paradoxical release of a large amount of LH (Luteal Surge), which, along with FSH, promotes the final development step of the follicle, leading to ovulation.

Why does only LH surge while FSH remains relatively lower during the Luteal Surge?

During the Luteal Surge, Inhibin, which is produced by the granulosa cells, reduces FSH release, while LH is less affected. As a result, there is a surge in LH but only a small increase in FSH, which leads to ovulation.