The Mentrual Cycle: Duration and Definitions

The last menstrual period relates to the

onset of menses

the first day of the menstrual cycle is said to occur on the

first day of bleeding

The average menstrual cycle lasts

28 days

ovulation typically occurring around —

day 14

some menstrual cycles may last only —, whereas others may last up to —

25 days; 45 days

Days — of the menstrual cycle correlate with menses, at which time the endometrium is shed

1 through 5

The first menstrual cycle is termed —

menarche

if an individual does not experience menarche before age 16, she is said to have —

primary amenorrhea

Primary amenorrhea may be caused by —

congenital abnormalities or congenital obstructions, such as an imperforate hymen

Secondary amenorrhea may be associated with —

endocrinologic abnormalities or pregnancy

Secondary amenorrhea that is not associated with pregnancy is characteristically diagnosed in the postmenarchal woman who has had —

3 to 6 months without a menstrual cycle