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.
1 After egg release, the luteal phase takes over. 2  Luteinizing hormone triggers the ovary to produce estrogen and progesterone. 3  These hormones cause the lining of the uterus to thicken, in preparation for a possible pregnancy. 4  If fertilization does not occur, the ovary stops making estrogen and progesterone.