Puberty Dr. sylvia. K Ram college
PUBERTY It is a physiological phase lasting 2 to 5 years , during which the genital organs mature
Manifestations of puberty in the female include: 1. Menarche, 2. Appearance of secondary sex characters, 3. Physical development and 4. Psychological changes.
Secondary sex characters include: development of the breast, appearance of pubic and axillary hair.
• The first sign of pubertal development is usually breast growth (thelarche), followed by appearance of pubic hair (pubarche), then ( axillary hair) , then ( menarche) . • The mean interval between breast budding and menarche is 2.5 years with a standard deviation of about one year .
Adrenarche means increased activity of the suprarenal cortex at puberty with increased production of adrenal androgens which lead to appearance of pubic and axillary hair.
Cause of puberty : • During childhood , the hypothalamus is extremely sensitive to the negative feedback exerted by the small quantities of estradiol & testosterone produced by the child's ovaries . • As puberty approaches , the sensitivity of the hypothalamus is decreased and subsequently , it increase the pulsatile GnRH secretion .
The anterior pituitary responds by progressive secretion of FSH and LH associated with increased secretion of growth hormone .
The ovaries respond to the increase Gonadotrophin secretion by follicular development & estrogen secretion .
• Estrogen causes development of the genital organs and the appearance of the secondary sexual characters . • With increased estrogen secretion , menarche and cyclic estrogen secretion occurs .
Factors affecting the initiation of pubertal development : 1 - Height and weight ratio (nutritional factors). 2 - Maturation of the hypothalamus . 3 - Increased neurotransmitter output in CNS . 4 - Onset of adrenal androgen activity
Deposition of SC fat: 17% to menstruate & 22% to ovulate
Genital organs changes: • Mons pubes, labia majora & minora : increase in size. • Vagina: 1. length: increase, appearance of the rugae 2. Epithelium: thick, stratified squamous., containing glycogen 3. pH: acidic.
Genital organs changes: • Uterus : enlarge, Uterus / Cervix :2 / 1 • Ovaries: 1.Increase in size, almond shape 2.300 thousands primary follicle at menarche ( 2 million at birth)
Adolescence : • Is the period of life during which the child becomes an adult person i.e. the physical , sexual and psychological development are complete . • Puberty represents the first part of adolescence .
Abnormalities of puberty 1 - Precocious puberty . 2 - Delayed puberty . 3 - Growth problems : during adolescence e.g. short stature or tall stature , marked obesity and menstrual disorders at puberty .
FEMALE PRECOCIOUS PUBERTY
Definition: It means menarche or appearance of any of the secondary sexual characters before the age of 8 years.
Types: 1 - True precocious puberty .
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