Related Experiment Video
Updated: Jul 31, 2026

Scanning Skeletal Remains for Bone Mineral Density in Forensic Contexts
Published on: January 29, 2018
Age at menarche in Thai girls
S Chompootaweep1, M Tankeyoon, P Poomsuwan
1Chulalongkorn University, Bangkok, Thailand.
Abstract:
Age at menarche and menstrual symptoms were recorded in a sample of Thai schoolgirls in Bangkok. Using a random sampling proportional to size from this target population, structured questionnaires were offered to a sample of 15998 girls of grades 4-12. Fifty-six per cent of the study population was menarcheal during the time of study. Average mean ages by recalling age at menarche and by probit analysis were 12.51 +/- 1.17 and 12.35 +/- 1.41 years, respectively. The onset of menstruation occurred most frequently in April and October. Abdominal pain was the most common symptom during the menstrual period. Acne, malaise and back pain were other common complaints.
Related Concept Videos
Nature and Nurture
Oogenesis
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Menopause

