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#Bone age less than chronological age skin

It generally lasts ∼ 2 years, girls complete it at age 15 and boys at age 17.Varies between the sexes, generally occurs between ages 13–15 years ( in girls, it can begin two years earlier).Linear growth during adolescence is approx.Gynecomastia is diagnosed in a pubertal male when the palpable subareolar gland and ductal tissue is ≥ 2 cm (see “ Pubertal gynecomastia”).Occurs approximately within 18 months of pubertal onset in males.Other morphological changes during puberty Further growth of pubic hair along linea alba in the direction of the umbilicus.Adult pubic hair that extends to the inner thighs with horizontal upper border.Adult pubic hair that does not extend to the inner thighs.Dark, coarse, curly hair spreading over the pubic symphysis.Sparse, lightly pigmented hair (straight or curled) on the labia/base of the penis.Usually no pubic hair, vellus hair possible.Testes, scrotum, and penis attain adult appearance and proportions.Penile growth continues: longer and wider penis.Continued enlargement of the testes and scrotum.

#Bone age less than chronological age skin

Scrotal skin darkens in color and texture.

Prepubertal appearance and size of the testes, scrotum, and penis.

Nipple and areola form a secondary mound which projects above the breast tissue.

Breast bud extends beyond the areolar diameter.

Slight increase in areolar diameter, nipple protrusion.

Enlarged mammary glands form a breast bud.

The first visible sign of puberty in males is testicular enlargement, while in females it is breast development.

Normal order of changes: adrenarche → gonadarche (age of onset 9–14 years ) → pubarche (mean age of onset 13.5 years ) → growth spurt (mean age of onset 13.5 years)→ androgenic hair growth.

Normal age of onset: 9–14 years(average 13 years).

Normal order of changes: adrenarche → gonadarche → thelarche (age of onset 8–11 years ) → growth s purt (age of onset 11.5–16.5 years) → pubarche(mean age of onset 12 years) → menarche (age of onset 10–16 years, mean age: 13 years).

Normal age of onset: 8–13 years(average 11 years).

Social environment (e.g., family stress).

General health (nutritional state, bodyweight).

FSH-stimulated Sertoli cells also secrete inhibin, which further inhibits FSH secretion from the pituitary.

Testosterone inhibits further GnRH secretion from the hypothalamus.

The hypothalamic-pituitary-gonadal axis is tightly regulated by a negative feedback mechanism.

Unknown initial trigger → ↑ activators and/or ↓ inhibitors of GnRH secretion → pulsatile GnRH secretion→ ↑ FSH and ↑ LH secreted by the anterior pituitary gland → stimulation of the Leydig cells and Sertoli cells in the testicles, and the theca and granulosa cells in the ovary.

See “ Physical changes during puberty” below.

Does not require treatment because menses become regular as hypothalamic-pituitary-gonadal axis matures.

Immaturity of the hypothalamic-pituitary-gonadal axis → irregular secretion of gonadotropins → short luteal phase, and lack of progesterone → endometrium remains in the proliferative phase → irregular menses and heavy menstrual bleeding.

Anovulatory cycle: The menstrual cycle may be irregular in adolescents during the first few months/years after menarche.

Gonadarche: activation of reproductive glands by the pituitary hormones FSH and LH.

Adrenarche: activation of adrenal androgen production (axillary and pubic hair, body odor, and acne ).

The age of pubertal onset may vary, but the order of changes that occur in each person is consistent. A phase of development between childhood and complete, functional maturation of the reproductive glands and external genitalia (adulthood).This delay can be constitutional (most common), secondary to underlying conditions, or due to hypogonadism. At the other end of the disease spectrum, puberty may be delayed or absent. When puberty begins abnormally early it is referred to as precocious puberty and is classified into two main types: peripheral precocious puberty, which is independent of gonadotropin-releasing hormone secretion and central precocious puberty, which involves the hypothalamo-hypophyseal axis. Although there is considerable variation between individuals, puberty begins on average at the age of 11 in girls and 13 in boys. The stages of development during puberty are classified according to the Tanner stages. The other processes that characterize this transitional phase are the development of secondary sex characteristics, growth spurts, and psychosocial changes. Puberty refers to the phase of development between childhood and adulthood in which complete functional maturation of the reproductive glands and external genitalia occurs.