They also cause the muscles of the uterus to contract, thus helping the uterus shed the lining built up during the first part of a woman's cycle.
prostaglandins
prostaglandins
If the egg fails to get fertilized by a sperm it has to be expelled and this process is started by the lowering of progesterone and estrogen levels that causes the uterus lining to break down and release a compound named prostaglandins. Prostaglandins causes the contraction of the uterine muscles that causes the breakdown of the egg and further contractions cause it to expelled through the vagina.
Prostaglandins produce diverse and even opposite effects. Some, for example, relax smooth muscles in the airways of the lungs and in blood vessels, while others contract smooth muscles in the walls of the uterus and intestines. Prostaglandins stimulate hormone secretion from the adrenal cortex and inhibit secretion of hydrochloric acid from the stomach wall. They also influence the movements of sodium ions and water molecules in the kidneys, help regulate blood pressure, and have powerful effects on male and female reproductive physiology.
The hormone-like chemicals responsible for menstrual cramps are called prostaglandins. These normally don't cause menstrual cramps, they are produced to cause the uterus to contract to push out menstrual flow, but in larger quantities they cause inflammation.
No
The inflammatory substance responsible for pain during menstruation is prostaglandins. The prostaglandins cause the uterine contractions, but in high quantities it will cause blood vessels supplying the uterus with blood to construct so starve the uterus of blood/oxygen very temporarily, and thus this is what causes the pain during menstruation.
Pain from menstrual cramps is a result of contractions of your uterus, which are caused by prostaglandins. Prostaglandins circulate in your bloodstream and they can cause diarrhea and gas because they also speed up contractions in your intestines.
Oxytocin.
Smooth muscles
Smooth muscles
During menstruation your body produces prostaglandins that cause the uterus to contract in order to push out menstrual flow, if prostaglandin production is too high it causes the blood vessels to contract so cutting off oxygen flow to the muscles in the uterus temporarily. Essentially it's similar to a heart attack: blocked blood vessels limiting blood flow and oxygen.