Some gases are lighter than air. Hydrogen is the lightest of all, and easily manufactured, even at home -- for example by dropping aluminium foil into a solution of sodium hydroxide (highly dangerous because it will spit droplets of hot caustic liquid at you which may blind you permanently if they land in your eyes).
The corpus luteum is essential for establishing and maintaining pregnancy in females. The corpus luteum secretes progesterone, which is a steroid hormone responsible for the decidualization of the endometrium (its development) and maintenance, respectively. It also produces relaxin, a hormone responsible for softening of the pubic symphysis which helps in parturition.
Progesterone a Fertility Drug for Endometrial Support. Progesterone is necessary for the proper development of the endometrium, which is the lining of the uterus. During the first half of the cycle (from the beginning of menses to ovulation), estrogen stimulates the endometrium to thicken and become more vascular.rogesterone levels are usually less than 2 ng/ml during the early part of the cycle and can rise to above 12 ng/ml within 5-6 days after ovulation. Once the embryos embed in the endometrium, and the placenta forms, the placenta produces progesterone.