Adrenarche and Puberty in Males

Adrenarche

• Increased secretion of adrenal androgens in both sexes
• Leads to the development of secondary sex characteristics

Secondary Sex Characteristics in Males

• Enlargement of internal genitalia (testes, ducts, and gland)
• Enlargement of external genitalia (penis and scrotum)
• Deep voice due to enlargement of the larynx and thickening of vocal cords
• Growth of hair in the face (beard and moustache), pubic area (triangular pattern), axilla, chest, anus, and other body areas
• Emotional changes (more active, aggressive, and interested in the opposite sex)
• Conformational changes (enlargement of muscles and broadening of shoulders)
• Secretion of sebaceous glands (predisposing to acne)

Secondary Sex Characteristics in Females

• Enlargement of internal genitalia (uterus and vagina)
• Enlargement of external genitalia (labia majora, labia minora, and clitoris)
• Enlargement of breasts
• High-pitched voice (no enlargement of the larynx)
• Deposition of subcutaneous fat (specially in breasts and buttocks)
• Development of pubic and axillary hair (triangular pattern with a flat top)
• Emotional changes and conformational changes (broad hips with narrow shoulders)

Abnormalities of Puberty

• Precocious puberty: early development of secondary sex characteristics due to early release of sex hormones (androgens in males, estrogen in females)
• True precocious puberty: associated with gonadotrophin release, enabling gametogenesis
• Pseudo precocious puberty: not associated with gonadotrophin release, not capable of gametogenesis

Puberty

• Definition: the period when the endocrine and gametogenic functions of gonads have first developed to attain reproductive capacity
• Onset: varies according to genetic and environmental factors, typically between 9-13 years in females and 11-15 years in males
• Mechanism of onset: unknown neural mechanism inhibits the release of gonadotrophins and GnRH in children, until CNS maturation initiates their release
• Features of puberty:
  • Growth spurt
  • Development of secondary sex characters
  • Enlargement of reproductive organs
  • Attainment of reproductive capacity
• Features of puberty in females:
  • Thelarche: development of the breast (an early feature of puberty in females)
  • Menarche: first menstrual cycle period
  • Pubarche: development of axillary and pubic hair

Definition and Onset of Puberty

• Puberty is the period when the endocrine and gametogenic function of gonads first develop to attain reproductive capacity.
• The onset of puberty varies according to genetic and environmental factors, occurring between 9-13 years in females and 11-15 years in males.

Mechanism of Onset

• Although the anterior pituitary gland of children contains gonadotrophins and their hypothalami contain GnRHs, their release is inhibited by an unknown neural mechanism.
• The release of these hormones is initiated by some sort of CNS maturation, but the exact mechanism is still unknown.
• The maturation initiates the release of GnRH in a pulsatile manner from the hypothalamus, leading to the release of gonadotrophin hormones (FSH & LH) from the anterior pituitary gland.
• The gonadotrophins control the function of the gonads and release of sex hormones (testosterone in males, estrogen and progesterone in females).

Features of Puberty

• Growth spurt
• Development of secondary sex characters
• Enlargement of reproductive organs
• Attainment of reproductive capacity

Features of Puberty in Females

• Thelarche: development of the breast (an early feature of puberty in females)
• Menarche: first menstrual cycle period
• Pubarche: development of axillary and pubic hair
• Adrenarche: increased secretion of adrenal androgens (in both sexes)

Secondary Sex Characteristics

In Males

• Enlargement of internal genitalia (testes, ducts, and gland)
• Enlargement of external genitalia (penis and scrotum)
• Deep voice (due to enlargement of the larynx and thickening of the vocal cords)
• Growth of hair in the face, pubic area, axilla, chest, anus, and other body areas
• Emotional changes (more active, aggressive, and interested in the opposite sex)
• Conformational changes (enlargement of muscles and broadening of shoulders)
• Secretion of sebaceous glands (predisposing to acne)

In Females

• Enlargement of internal genitalia (uterus and vagina)
• Enlargement of external genitalia (labia majora, labia minora, and clitoris)
• Enlargement of breasts
• High-pitched voice (no enlargement of the larynx)
• Deposition of subcutaneous fat (especially in breasts and buttocks)
• Development of pubic and axillary hair (due to adrenal androgens)
• Female pattern of hair distribution at the pubic area (triangular with the apex facing down)
• Emotional changes and conformational changes (broad hips with narrow shoulders)

Abnormalities of Puberty

Precocious Puberty

• Early development of secondary sex characteristics due to early release of sex hormones (androgens in males, estrogen in females)
• The early release of sex hormones may be or may not be associated with gonadotrophin release
• When gonadotrophins are also released, the child becomes capable of gametogenesis (True precocious puberty)
• When gonadotrophins are not released, the child is not capable of gametogenesis (Pseudo precocious puberty)

Causes of Precocious True Puberty

• Unknown