Question

In uterus, the endometrium proliferates in response to:
a. Relaxin
b. Oxytocin
c. Progesterone
d. Oestrogen
e. Luteinizing hormone

Answer 1

Hormones are chemical messengers which are secreted from the endocrine or the ductless glands directly into the bloodstream.

Complete answer:

Relaxin hormone is secreted by the placenta. Its function is to dilate the cervix during the delivery of the baby. It also prepares the uterus for labor pain.

Oxytocin is the hormone which is released from the posterior pituitary but it is synthesized in the paraventricular nuclei of the hypothalamus. It is a peptide hormone made up of 9 amino acids.
The most important function of this hormone is to cause the contraction of the uterus and the uterine wall during childbirth. The milk from the mammary glands of the mother is secreted due to this hormone.

Progesterone helps in keeping the myometrium quiet. This hormone is responsible for the growth and the appearance of secondary sexual characteristics in females. Most of the changes in the body of the woman during pregnancy are due to this hormone.

Oestrogen is the hormone secreted from the ovary. It stimulates secondary sexual characteristics in females. This is the hormone which makes the uterus grow during pregnancy. The growth in the mammary glands takes place due to the presence of a high amount of oestrogen in the body.

Luteinizing hormone causes ovulation. It maintains the corpus luteum and helps in the secretion of progesterone in females and testosterone in males.

Hence, the correct answer is option (d).

Note: Here it must be noted that the phase at which the endometrium proliferates is known as the follicular phase. During this phase the cells of the endometrium multiply. The oestrogen level in the body increases due to which the endometrium thickens.