Video Transcript
What is the primary function of progesterone? (A) To promote the development of male secondary sexual characteristics, for example,
facial hair growth. (B) To maintain the uterus lining in the second half of the menstrual cycle and
during a pregnancy. (C) To regulate digestion and metabolism of fats, proteins, and carbohydrates. (D) To regulate salt and water balance in body fluids.
This question asks us about progesterone, which is a hormone secreted by the
ovaries. Here’s a diagram of the female reproductive system with the ovaries indicated. Let’s review some hormones that the ovaries secrete in order to answer this
question.
The first hormone we’ll discuss is estrogen. Estrogen controls ovulation during the menstrual cycle, which is the process where a
mature egg is released by the ovary for potential fertilization by sperm. Estrogen also controls the development of secondary sexual characteristics in
females, such as the development of the breasts, the widening of the hips, and the
regulation of the menstrual cycle. In males, the hormone testosterone promotes the development of male secondary sexual
characteristics.
Once an egg is released into the Fallopian tube after ovulation, another hormone
called progesterone is secreted. Progesterone is produced from the follicle left behind in the ovaries after
ovulation. This empty follicle develops into the corpus luteum. The main role of progesterone is to maintain a thick lining of the uterus. When the lining of the uterus is thick, an embryo can implant and develop into a
fetus during pregnancy.
The last hormone we’ll discuss that’s secreted from the ovaries is relaxin. Relaxin is also produced from the corpus luteum and assists in relaxing parts of the
female reproductive system to prepare the embryo for implantation. Later in pregnancy, it’s secreted by the placenta and uterine lining and plays a role
in preparing the body for labor during childbirth.
Now that we’ve gone over the functions of some of the hormones produced by the
ovaries, we can answer our question. The primary function of progesterone is given by answer choice (B): to maintain the
uterus lining in the second half of the menstrual cycle and during a pregnancy.
