Puberty

Puberty is the stage of life at which secondary sexual characteristics appear. Girls begin dramatic development and maturation of reproductive organs at approximately 12 to 13 years of age.

Although the mechanism that initiates this radical change is not well understood, the hypothalamus under the direction of the central nervous system may initiate or regulate the mechanism to "turn on" the gonadal functioning at this age.

There is a wide variation in the times that adolescents move through developmental stages. However, the sequential order is relatively constant.

In girls, pubertal changes occur typically indicated by:

• Marked physical growth.
  
• Increase in the transverse diameter of the pelvis.
  
• Breast development.
  
• Growth of pubic and axillary hair.
  
• Vaginal secretion and menarche.