The Menstrual Cycle Biology 12

The Menstrual Cycle controlled by internal feedback mechanisms between the reproductive system and the endocrine system the cycle takes an average of 28 days

The Menstrual Cycle during the cycle: if fertilized: an egg develops and is released from an ovary the uterus prepares to receive a fertilized egg if fertilized: the egg implants and uterus and embryonic development begins if not fertilized: the egg is discharged

The Menstrual Cycle four phases: follicular phase ovulation luteal phase menstruation

The Menstrual Cycle

Follicular Phase begins when estrogen levels are low pituitary secretes FSH and LH follicle develops to maturity follicular cells produce more estrogen uterine lining (endometrium) thickens

Ovulation midway through cycle lasts 3 to 5 days pituitary produces more FSH and LH follicle ruptures mature egg is released into one of the fallopian tubes

Luteal Phase begins when egg is released egg moves down the fallopian tube follicle turns yellow and is called the corpus luteum continues to release estrogen also releases progesterone

Luteal Phase progesterone stimulates growth and development of the blood supply to surrounding tissues within a few days of implantation, the uterus and growing embryo release hormones that keep the corpus luteum functioning for several weeks endometrium will nourish and protect the embryo

Menstruation if no fertilization, the corpus luteum disintegrates less hormones, so the endometrium detaches tissues, blood, and the unfertilized egg are discharged through the vagina lasts 3 to 7 days

The Menstrual Cycle

The Menstrual Cycle The Menstrual Cycle Animation The Menstrual Cycle Graph