Adolescent Growth Year 4 Paediatrics Notes OmpathStudy

Adolescent Growth Year 4 · Paediatrics Collection: 4TH YEAR ALL NOTES / PAEDS / PAEDS 4.3 / Munge / NUTRITION -- Slide 1 Adolescent Growth Dr Rose Munge Slide 2 Definition Changes in physical appearance, but also rapid changes in physiologic, psychological, and social functioning.\nHormonally driven physiologic changes and ongoing neurologic development occur in the setting of social structures that foster the transition from childhood to adulthood.\nDivided into 3 phases— early, middle, and late adolescence—each marked by a characteristic set of biologic, cognitive, and psychosocial milestones Slide 3 Individual variations in the timing and pace of development exist, but these changes follow a fairly predictable pattern of occurrence. \nGender and culture profoundly affect the developmental course, as do physical, social, and environmental influences. Slide 4 Physical Development Puberty is the biologic transition from childhood to adulthood.\nPubertal changes include the appearance of the secondary sexual characteristics, increase in height, change in body composition, and development of reproductive capacity. Adrenal production of androgen, mainly dehydroepiandrosterone sulfate (DHEAS), may occur as early as 6 yr of age, with development of underarm odor and faint genital hair (adrenarche ). Slide 5 Maturation of the gonadotropin releasing hormone (GnRH) pulse generator is among the earliest neuroendocrine changes associated with the onset of puberty.\nUnder the influence of GnRH, the pituitary gland secretes luteinizing hormone (LH) and follicle-stimulating hormone (FSH);\nInitially this occurs in a pulsatile fashion primarily during sleep, but this diurnal variation diminishes throughout puberty.\nLH and FSH stimulate corresponding increases in gonadal androgens and estrogens.\nThe triggers for these changes are incompletely understood\nBoth genetic and environmental (epigenetic) contributions to the regulation of pubertal timing are likely. Slide 6 Sexual Development The progression of the development of the secondary sex characteristics may be described using the sexual maturity rating (SMR) scale (ranging from 1, preadolescence, to 5, sexual maturity), or Tanner stages.\nDepict the physical findings of breast and pubic hair maturation at each SMR The ages at which individual pubertal changes occur may vary, the timing and sequence of these changes relative to one another is predictable\nThe wide range of normal progress through sexual maturation is affected by genetics, the psychosocial environment, nutrition, and overall health status.\nEnvironmental exposures may play a role as well. Slide 9 In males the first visible sign of puberty and the hallmark of SMR 2 is testicular enlargement, beginning as early as 9.5 yr, followed by the development of pubic hair.\nThis is followed by penile growth during SMR 3. Peak growth occurs when testis volumes reach approximately 9-10 cm3 during SMR 4.\nUnder the influence of LH and testosterone, the seminiferous tubules, epididymis, seminal vesicles, and prostate enlarge.\nSperm may be found in the urine by SMR 3; nocturnal emissions may be noted at this time as well.\nSome degree of breast tissue growth, typically bilateral, occurs in 40–65% of males during SMR 2-4 as a presumed consequence of a relative excess of estrogenic stimulation.\nThis usually resolves with ongoing maturation Slide 10 In females, typically the first visible sign of puberty and the hallmark of SMR 2 is the appearance of breast buds (thelarche ), between 7 and 12 yr of age.\nSome females develop pubic hair (pubarche ) prior to thelarche.\nLess visible changes include enlargement of the ovaries, uterus, labia, and clitoris and thickening of the endometrium and vaginal mucosa.\nA clear vaginal discharge may be present before menarche (physiologic leukorrhea). Menses typically begins within 3 yr of thelarche, during SMR 3-4 (average age 12.5 yr; normal range 9-15 yr) Slide 11 The timing of menarche is by genetics; contributing factors likely include adiposity, chronic illness, nutritional status, and the physical and psychosocial environment.\n Early menstrual cycles often are anovulatory irregular, but typically occur every 21-45 days and include 3-7 days of bleeding, even during the 1st year following menarche. Slide 12 Somatic Growth Linear growth acceleration begins in early adolescence for both genders, with 15–20% of adult height accrued during puberty.\nFemales attain a peak height velocity (PHV) of 8-9 cm/yr at SMR 2-3, approximately 6 mths before menarche. Males typically begin their growth acceleration at a later SMR stage, achieve a PHV of 9-10 cm/yr later in the course of puberty (SMR 3-4), and continue their linear growth for approximately 2-3 yr after females have stopped growing Slide 13 Somatic Growth cont. The growth spurt begins distally, with enlargement of the hands and feet, followed by the arms and legs, and finally the trunk and chest. Imparts a characteristic “awkward”