Question

The pubic symphysis becomes lax in pregnancy because of what?

a. The pressure of the baby's head on the pelvic bone.

b. The hormone called relaxin.

c. Exercise during pregnancy.

d. A reduction of elastin in the pubic bone symphysis.

Answer 1

The pubic symphysis becomes lax during pregnancy due to the hormone relaxin, which enhances the elasticity of pelvic joints and ligaments to accommodate childbirth.

Step-by-step explanation:

The pubic symphysis becomes lax in pregnancy primarily because of the hormone relaxin, which is secreted first by the corpus luteum and then by the placenta. Relaxin is responsible for increasing the elasticity of the symphysis pubis joint and pelvic ligaments. This physiological change is critical as it makes room for the growing fetus and facilitates the expansion of the pelvic outlet for childbirth. Furthermore, relaxin also plays a role in helping to dilate the cervix during labor.

Answer 2

The pubic symphysis becomes lax in pregnancy primarily due to:

The hormone called relaxin.

The correct option is B.

Step-by-step explanation:

During pregnancy, the hormone relaxin is produced by the corpus luteum of the ovary and later by the placenta. This hormone plays a significant role in preparing the body for childbirth by relaxing the ligaments and tissues, including the pubic symphysis. Relaxin helps to loosen the ligaments and joints in the pelvic area, allowing for increased flexibility and accommodating the growing fetus during delivery.

So, the correct option is B.