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.
The changes in the internal uterine lining of the uterus - the endometrium - during the menstrual cycle is termed the uterine cycle of menstruation. These changes occur in response to the hormones, estrogen and progesterone, secreted by the ovaries during the ovarian cycle of menstruation. The Uterine cycle of menstruation starts from the first day of the menstrual period, which is also the first day of bleeding. It can be divided into three distinct phases: