Module 3

Module 3—The Male and Female Reproductive Systems

Lesson 7—Female Hormones

Get Focused

Although there is a lack of scientific understanding of the hormonal process that triggers an embryo to undergo female sexual development, there is a very good understanding of what happens during puberty, the menstrual cycle, and aging. Being female is designated by the chromosomal arrangement of two X chromosomes, which causes a female to develop female genitalia, begin having a menstrual cycle, and undergo menopause. The beginning of the menstrual cycle allows the female to fulfill her role in the continuation of the species.

The beginning of puberty is similar in men and women. The beginning of puberty is defined when the hypothalamus begins producing more gonadotropin releasing hormone (GnRH). GnRH then stimulates the anterior pituitary to start producing both follicle-stimulating hormone (FSH) and luteinizing hormone (LH). FSH and LH then act on the female gonads (the ovaries), to produce the female sex hormones estrogen and progesterone. Once estrogen and progesterone are secreted, they cause the maturation and development of the female primary and secondary sex characteristics and the start of the menstrual cycle.

When Jane, from Couple 1 in “A Fertility Case Study” was in high school, she was a competitive gymnast. Her skill level was very good and she was competing at the provincial and national level. In her Grade 11 year, Jane was 17, she was 5-foot-3 (1.6 m) and weighed 95 pounds (45 kg). What most people did not know was that Jane had an eating disorder, which she had battled since she was 10. Furthermore, at 17, she had not yet started menstruating. When she started training in Grade 12, she looked very fragile. Her coach was concerned about her well-being, and stopped her from competing in several early competitions and decreased her training by two-thirds. The coach shared his concerns with Jane's parents.

Jane discovered that when a woman of reproductive age is placed under physically demanding training regimes and the stress of competition, and has an eating disorder, her body may suffer from the absence of menstrual periods, called amenorrhea.

Jane knew that she wanted children one day, so she decided to learn more about normal female reproductive hormone control and how her training and eating disorder were affecting her reproductive system. To understand what was happening to her body, she needed more information to make better decisions in her life now and in the future.

In this lesson you will examine the following focusing questions:

• What are the female reproductive hormones?

• How do hormones maintain homeostasis in the female reproductive system?

• What role do the female hormones play in regulating primary and secondary sex characteristics?

Module 3: Lesson 7 Assignment

There is no assingment for this lesson.

You must decide what to do with the questions that are not marked by the teacher.

Remember that these questions provide you with the practice and feedback that you need to successfully complete this course. You should respond to all of the questions and place those answers in your course folder.

Make any notes about “A Fertility Case Study” from this lesson and place them in your course folder for your teacher’s feedback.

Remember that you also have the option of trying additional questions from the textbook for further practice. Consult with your teacher for the answers to these questions. The Key will also provide you with many Diploma Exam-style multiple-choice, numerical-response, and written-response questions that will be an excellent review of the module. Practising your responses to these types of questions is good preparation for the Diploma Exam.