Body Growth and Change, Hormonal changes

Body Growth and Change

Puberty

Hormonal changes

Powerful chemicals from endocrine glands

Hypothalamus – eating and sexual behavior

Pituitary gland – controls growth, regulates glands

Gonads – male testes, female ovaries

Gonadotropins – stimulate testes, ovaries

The hypothalamus is a structure in the brain best known for monitoring eating, drinking, and sex. 

The pituitary gland is an important endocrine gland that controls growth and regulates other glands. 

The gonads are the sex glands—the testes in males, the ovaries in females. 

The key hormonal changes involve two classes of hormones that have significantly different concentrations in males and females. 

Androgens are the main class of male sex hormones .  

Estrogens are the main class of female hormones. 

Testosterone is an androgen that is a key hormone in the development of 

puberty in boys. As the testosterone level rises during puberty, external genitals 

enlarge, height increases, and the voice changes. 

Estradiol is an estrogen that plays an important role in female pubertal development. As the estradiol level rises, breast development, uterine development, and skeletal changes occur.

Hormones increase dramatically in adolescence

Testosterone – voice change, genital growth

Dominates male changes

Estradiol – estrogen for breast growth

Dominates female changes

Onset affects social competence

Behaviors and moods can affect hormones

Links between hormones and adolescent behavior?

Findings are inconsistent.

Hormonal factors alone are not responsible.

Social factors  in young adolescent girls’ depression and anger.

Hormones do not act independently; 

Hormonal activity is influenced by many environmental factors, including parent adolescent relationships. 

Stress, eating patterns, sexual activity, and depression can also activate or suppress various aspects of the hormone system.

Body Growth and Change : ADOLESCENCE

 Body Growth and Change  - ADOLESCENCE:

Puberty : is a period of rapid physical maturation involving hormonal and bodily changes that occur primarily in early adolescence. The features and proportions of the body change as the individual becomes capable of reproducing.

Puberty

 Determinants of Puberty: important physical changes and psychological accompaniments

Period of rapid physical and hormonal changes

Physical changes; growth spurt

Determinants of Puberty:

 important marker for the beginning of adolescence.

There are wide variations in the onset and progression of puberty. 

begin as early as 10 years of age or as late as 13½ for boys. It might end as early as 13 years or as late as 17 years.

Girls – menarche (a girl’s first menstruation), hips widen, body hair. Onset for most: 9 to 15 years of age. 

Boys – first ejaculation, grow taller, body hair.  Onset for most: 10 to 17 years of age.

Precocious puberty is the term used to describe the very early onset and rapid progression of puberty. Onset occurs before 8 years of age in girls and before 9 years of age in boys.

10 times more often in girls than in boys. When it occurs, usually treated with suppressing gonadotropic secretions, which temporarily stops pubertal change. The reasons for this treatment is that children who  have short stature, early sexual capability, and the potential for engaging in age-inappropriate behavior.

The most important factors that influence the onset and sequence of puberty are heredity, hormones, weight, and body fat.

 Heredity:  Programmed into the genes of every human being is a timing for the emergence of puberty. Nonetheless, within the boundaries of about 9 to 16 years of age, environmental factors such as health, weight, and stress can influence the onset and duration of puberty.

Hormones: Hormones are powerful chemical substances secreted by the endocrine glands and carried through the body by the bloodstream. In puberty, the secretion of key hormones is controlled by the interaction of the hypothalamus, the pituitary gland, and the gonads (sex glands).