Video Transcript
Relaxin is a hormone produced by
the ovary. What is the primary role of relaxin
in the human body? (A) To counteract the effects of
adrenaline after a fight-or-flight response. (B) To initiate the contraction and
relaxation of skeletal muscles. (C) To prepare the female body for
pregnancy and labor. (D) To regulate the menstrual
cycle.
This question asks us about
relaxin, 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 secreted by the
ovaries that 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 its primary 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 relaxin is
given by answer choice (C): to prepare the female body for pregnancy and labor.
