HHD Physical characteristics of youths development Part 2

HHD Physical characteristics of youths’ development (Part 2) The Menstrual Cycle

The Menstrual Cycle � Signifies a woman’s ability to bear children � Menarche usually occurs between 11 -14 years of age � On average, a menstrual cycle lasts 28 days � Involves a delicate interplay of hormones � Oestrogen, Progesterone, FSH and LH are all present during the menstrual cycle. However, the release of and contribution of these hormones occurs at different stages during the 28 day cycle. The menstrual cycle explained

Day 1 -7 - Bleeding commences Lining of uterus (endometrium) is discharged Pituitary gland releases FSH which travels in bloodstream to the ovaries FSH stimulates an ovum to start maturing in follicle Follicles are small sacs that contain an immature ovum as it develops Fallopian Tube

Day 7 -12 - As follicles begin to mature, oestrogen is released by the ovaries Oestrogen travels to the uterus where it stimulates the growth of a new blood lining to prepare for possible pregnancy Oestrogen (blood lining)

Day 13 -15 - High Oestrogen levels cause the pituitary gland to switch from making FSH to LH, which stimulates ovulation Oestrogen LH

Day 14. Ovulation - The LH hormone causes the follicle to burst, releasing an egg from an ovary into the fallopian tube. - This process is called ovulation - Peak fertility time - The empty follicle is now called the corpus luteum

Day 15 -28 - - Ovum travels down fallopian tube and into uterus Follicle keeps on making Oestrogen and Progesterone which causes the endometrium to continue to thicken in case conception occurs If ovum is fertilised by sperm it implants into endometrium Unfertilised egg dies At end of cycle, hormone levels drop and next menstrual cycle beings on day 28 Progesterone Ovum Endometrium continues to thicken Follicle Oestrogen