Physical changes of puberty in boys
- Growth and development of the genitalia: Initial growth of the testicles and scrotum begins at age 10 - 13.5 and is completed at age 14 - 18.5. The scrotum becomes wrinkled and red, and the testicles are ready for sperm production and secretion.
- Growth of body pubic, underarm, and facial hair: Testosterone (male sex hormone) is responsible for the growth of pubic, underarm, and facial hair. Due to the social effects of facial hair growth, this change is of great importance to adolescent boys. At first, the pubic hair and two years later the armpit and facial hair grow. As the hair grows on the chest and face, sweat and oil glands secretions increase and contribute to the formation of acne.
- First nocturnal emission : occurs one year after the growth of the testes, about the age of 14-15 . It usually occurs spontaneously at night or in the early morning and during sleep. The first ejaculation should not cause any concerns for adolescents; on the contrary, it should be seen as a sign of becoming an adult and a welcome phenomenon.
- Penis growth: On average, penis growth starts at 12.5 years of age.
- Height, arms, and legs growth: At 14.5 years of age , the male "growth spurt" begins and height increases by 7.5 to 12.5 cm in one year, and about the age of 15, boys reach 98% of their final height. The leg and arm bones grow faster than other bones and at the onset of height growth, the legs are much taller than the trunk.
- Body shape undergoes a child-to-adulthood transition, muscular and physical strength and chest width increases and body becomes masculine.
- Voice change in boys takes place gradually, when the vocal cords grow longer (become almost double in length), causing a voice crack and gradually making the male voice to become deeper and more masculine.
- The process of emergence of these physical changes and the age at which they occur, vary in different individuals. So there is no need to worry about this. Sooner or later all healthy adolescent boys will experience the above phenomena. The degree and pace of physical growth in adolescence is influenced by a number of hormonal, genetic and environmental factors.
- Environmental factors affecting physical growth include: good and adequate nutrition, exercise and physical activity, physical and mental well-being
Objective
Knowledge
Thematic Area
The Human Body and Development
Country
IRN
Yes