Development of primary sex characteristics
The reproductive organs of girls and boys become functional completely at the onset of puberty.
In males, the testes, penis, and seminal vesicles comprise the primary sexual characteristics.
The primary sexual characteristics include the internal and the external sex organs present at the time of birth. They are involved directly in the process of reproduction.
During puberty, there is a production of gametes, sperms and ova in males and females respectively. In boys, testes grow larger, and there is an increase in the length and size of the penis. In females, the ovary, oviducts, uterus, vagina, etc., are the primary sexual characteristics.
The female reproductive organ also grows during puberty. The size of the uterus and the weight of the ovaries increase at the onset of puberty.
Development of secondary sex characteristics
Physical characteristics which develop at puberty distinguishes males from females. These are called secondary sexual characteristics.
Secondary sex characteristics are the physical characteristics which distinguish males from females. They do not involve in reproduction directly. After the onset of puberty, boys and girls become different and dissimilar in appearance. The secondary sex characteristics are controlled and regulated by hormones.
In males, testosterone or androgen is the hormone that regulates secondary sex characteristics. The testes secrete the androgen hormone in males. In females, the hormone estrogen is secreted by the ovaries. These hormones regulate the secondary sex characteristics in females.
Role of androgens/testosterones
In males, androgens play a role in:
- Growth of the larynx - lengthen and thicken the vocal cords in males
- Muscle development and skeletal size
- Distribution of the body and pubic hair
- Stimulation of sweat glands
Secondary sexual characteristics in male
In females, estrogen plays a role in:
- Stimulating the development of the breast
- Aiding in the development of the external genitalia
- Distribution of the pubic and axillary hairs
- Distribution of body fat.
Secondary sexual characteristics in female
The other changes that occur during adolescence are emotional and intellectual maturity.
Mental, emotional, and intellectual maturity
Adolescence is also a period which brings a maturity that causes a change in the way a person thinks. Adolescents become more independent and self-conscious as they attain mental maturity. During adolescence, intellectual development takes place, and adolescents start reasoning and understanding things. During this age, the brain has the maximum learning capacity.
In adolescence, girls and boys may get into insecurities and emotional mood swings when adjusting to the changes in the body and in mind. However, adolescents should understand that all changes are entirely normal and are a part of growing.
The below explains the secondary sexual characters happens in human.