What is the onset of the first menstrual period in girls during puberty called?

1. The chapter describes puberty as marking the end of childhood and the start of adolescence. 2. Hormones released during puberty produce primary and secondary sex characteristics. 3. In girls, rapid growth in height begins about two years before the first menstrual period. 4. The chapter names that first menstrual event menarche. 5. Hence the first menstrual period is called menarche. _Source: syllabus Psychology Ch 3 "Human Development", p. 53, Physical Development in Adolescence_