Some of these incoming fibers go to the motor nucleus of the trigeminal nerve (V), bypassing the pathways for conscious perception. The jaw jerk reflex is an example; tapping the jaw elicits a reflex closure of the jaw in the same way that tapping the knee elicits a reflex kick of the lower leg.
FSH stimulates the production of eggs and LH stimulates the release of the egg. FSH and LH are produced by the pituitary gland in the brain. There are four stages in the menstrual cycle. Stage 1. Days 1-4. Menstruation (bleeding) occurs. The lining of the uterus disintegrates and is shed. This is due to low levels of progesterone. Stage 2. Days 4-14. The uterine lining grows back.
During the first part of each menstrual cycle, one of the eggs is being prepared for release from the ovary. As you approach ovulation, your body produces increasing amounts of a hormone called estrogen, which causes the lining of your uterus to thicken and helps create a sperm friendly environment. These high estrogen levels trigger a sudden increase in another hormone called LH (Luteinizing Hormone).