endocrine
the Endocine system.
It is important to know the roles of each system in the body. The reproductive and the endocrine system is the cause of the onset of the menstrual cycle.
Yes
Usualy somewhere between 11 and 15.
Hormones are responsible for the onset of menses. When the body produces enough hormones, the menstrual cycle begins.
The hormone that causes ovulation to occur in the menstrual cycle is called luteinizing hormone (LH).
purberty for girls around whenever they're in 6th grade
menarche; 12
You can't have a two day menstrual cycle. A menstrual cycle is the entire reproductive cycle, including ovulation and menstruation, so you can't possibly have a two day menstrual cycle. You may experience two day menstruation, or mid-cycle spotting for two days.
Various things can happen to cause bleeding outside of the menstrual cycle. For example, it is possible for sex to cause bleeding.
The menstrual cycle is controlled by hormones, specifically estrogen and progesterone, which are produced by the ovaries. These hormones regulate the different phases of the menstrual cycle, including ovulation and menstruation. Additionally, the hypothalamus and pituitary gland in the brain play a role in controlling hormone production.
Bloating and tenderness, cramps in the abdomen, headaches, irritability and ultimately vaginal bleeding are all signs of the onset of the menstrual cycle.