Puberty-Endocrine Aspect Flashcards
Puberty is the stage of _________________ , ending in _________________.
Involves morphological, physiological and behavioural changes.
Commence toward the end of the __________ decade of life.
The changes of puberty occur because of orderly, sequential changes in endocrine activity.
sexual maturity ; reproductive capability.
first
Puberty
Occurs between ___-____ years of age in girls.
____-_____ years of age in boys. [range of 12- 20yrs]
8 - 14
9 - 14
Endocrine Control of Puberty
List 7
Gonadotropin Releasing Hormone[GnRH]
Gonadotropins [Follicular Stimulating Hormone(FSH) & Luteinizing Hormone (LH)]
Growth Hormone
Insulin-like Growth Factor 1[IGF1]
Gonadal Steroids
Insulin
Leptin
Inhibin
A peptide hormone secreted by the ________ cells of the ________ and the ________ cells of the ________ .
It (Up or Down?) regulates ______ synthesis
It Inhibits secretion of ______
follicular; ovary; sertoli; testes
Down; FSH
FSH
Hypothalamo-Pituitary-Gonadal Axis
The beginning of adolescent-related puberty is a function of the hypothalamo- pituitary-gonadal axis maturation.
_________ in the frequency of GnRH [Gonadotropin Releasing Hormone] pulse stimulation is one of the important neuroendocrine mechanisms.
↑
Sequential events leading to puberty
In ________ and in the first ________________ , the hypothalamic-pituitary- gonadal (HPG) axis shows a period of activity.
Becomes quiescent by ____________ of age until the time of puberty.
utero
few postnatal months
6 months
Sequential events leading to puberty (2)
Pulsatile secretion of ________ from the _________ results in pulsatile secretion of the _________ gonadotropins, ______ and _________ .
Increasing LH production triggers an increase in production of ____________,
While, increasing FSH stimulates the growth and maturation of the _______________ and ______________
GnRH; hypothalamus; pituitary
LH and FSH
sex steroids
seminiferous tubules and the ovarian follicles.
IGF [Insulin Growth Factor 1]
IGF-1 is an important modulator of growth during childhood and adolescence.
IGF-1 conc _______ markedly through puberty reaching peak values approx ______ later in boys than in girls.
↑
1yr
Insulin
Insulin is also important for normal growth.
Plasma insulin levels ________ throughout childhood but the rise is particularly pronounced during _________ with a strong positive correlation with _______.
↑
puberty
IGF-1
LEPTIN
A protein hormone produced by __________ .
Important in (male or female?) puberty which usually will not proceed until an adequate body mass has been achieved.(at least ______kg)
adipose tissues ; female
40
GONADAL STEROIDS
Sex steroids induce a _________ growth spurt even when _______ is absent, suggesting that oestradiol acts on both on the _______________________ and _________
subnormal; GH
secretion of GH from the pituitary & the growth plate.
Sex steroids
Oestrogen is important for skeletal __________ and __________ of the __________.
It also augments ______ release.
Testosterone is an _____bolic hormone and acts on androgen receptors in responsive tissues throughout the body.
maturation
fusion of the epiphysis.
GH ( anabolic
Sex steroids
Oestrogen is important for skeletal __________ and __________ of the __________.
It also augments ______ release.
Testosterone is an _____bolic hormone and acts on androgen receptors in responsive tissues throughout the body.
maturation
fusion of the epiphysis.
GH ( anabolic
Hormones behind somatic signs of puberty
Boys
FSH, LH
• Growth of __________ (__________)
• __________ production
Testosterone
• Growth of __________, __________.
Sexual hair, acne, adult sweat odour, muscles, voice change
Oestrogen
-__________ closure -__________
testicles ; spermatogenesis
Testosterone ; scrotum ; penis.
Epiphyseal ; Gynecomastia
Hormones behind somatic signs of puberty
Girls
FSH, LH
• _________ maturation (size, follicles)
• _________ production
Estradiol
• Growth of _________, _________, fat over buttocks, thighs, vaginal discharge, menstruations
Testosterone
Sexual _______, ______, adult _________, muscles, libido
Ovarian ; Estradiol
breasts; uterus,
hair, acne, adult sweat odour
PUBERTAL STAGING
The physical changes of puberty in individuals are defined by the ________ stages.
Females-Breast development and pubic hair
Males- External Genitalia and pubic hair
Tanner
PUBERTY AND GROWTH-2
Also the testes _______________________________ hence the later puberty.
Growth spurt starts with the ______________ and moves (proximally or distally?) to finish with the ___________.
require high levels of gonadotropin stimulation than ovaries
hands & feet
Proximally; trunk
WEIGHT GAIN IN PUBERTY
Marked changes in body composition occur during puberty.
Boys gain approx ____kg in wt over puberty (from 12-18yrs) ____% being accounted for by ___________ [FFM]
Girls gain approximately _____kg only ____% being FFM.
30; 82
fat-free mass
18.5; 68
Contributing Factors to Timing of Puberty
___________ (twins)
___________ ___________ (SGA)
Changing life condition (___________) Chemicals, environment
___________ status (anorexia nervosa) ___________-situations (sport, war)
Brightness, ___________ (blind girls)
Climate
Genetics
Intrauterine development
adoption
Nutritional
Stress
photoperiods
PRECOCIOUS PUBERTY
Conventional Definition:
___________________ present before age:
– 8 years in girls – 9 years in boys
Lawson Wilkins Pediatric Endocrine Society (LWPES) statements (1999, 2003):
Girls present early puberty at age:
_____years (African-American girls)
—— years (White girls )
2 or more pubertal signs
6-8
7-8
Causes of Precocious Puberty (PP)
Origin in CNS (gonadotropin ________ [CPP]) • Idiopathic (most often _______)
• Tumours (harmatoma, optic glioma)
• Increased _______________
• Defects of _____________ function eg Testotoxicosis
dependent
familial; intracranial pressure
LH receptor
Causes of Precocious Puberty (PP)
Primary cause in gonads(gonadotropin ___________ [PPP]
• Tumours
• ____________ , ____________ syndrome
Primary cause in adrenals(gonadotropin ________________ ) •_________________ (CongenitalAdrenalHyperplasia)
• Tumours
independent; Ovarian cysts
McCune-Albright
independent; Enzymedeficiencies
Causes of Precocious Puberty (PP)
Others:Long-standing _________ ___________
Markedly elevated ______ secretion might stimulate the FSH receptor
primary hypothyroidism
TSH
Management of PP 1/5
Detailed history
Physical Examination:
─______________
─ __________ staging
─ Dermatological [______________,
______________]
─ Neurological
─Anthropometry
─ Tanner staging
─ Dermatological [Mc-Cune-Albright,
Neurofibroma] ─ Neurological
Management of PP 2/5
Investigations:
Baseline ____,_____
_____________(______ or _____)
Adrenal steroids/metabolites[if indicated]
____________ tests [if indicated]
_______ stimulation tests
FSH,LH
Gonadal steroids [E2 or T]
Thyroid function
GnRH
Management of PP 3/5
Imaging:
___________ -provides indication of skeletal advancement from excess _______. Useful in calculation of final height.
Pelvic Ultrasound
CT Scan/MRI especially in boys or girls with neurological signs.
Bone Age; steroids
Management of PP 4/5
Treatment:
Directed at the cause
Treatment of underlying disease conditions
CPP- Treatment with _________ (Leuprorelin,Goserelin, Triptorelin)
[pituitary gonadotrophs are subjected to prolonged rather than the physiological pulsatile GnRH levels.]
GnRH agonists
DELAYED PUBERTY
Delayed onset :
Females: Breast bud does not appear till ___________ or
•Menarche does not occur till _________
Males: No testicular enlargement by __________of age
13 years; 16 years
14 years
DELAYED PUBERTY
Delayed progression [Arrested ]:
Females: Menarche does not occur within _________ after breast bud
Males:
Incomplete development of the genitalia __________ after commencement.
5 years
5 years
Management of PP 5/5
Peripheral PP:
Replacement therapy- CAH: _____________ , Hypothyroidism : ____________
Oversecretion of hormones
─Medroxyprogesterone (Antigonadotropic + inhibitor of biosynthesis of gonadal steroids)
─Cyproterone acetate (Antigonadotropic + antiandrogen)
─ _______________ (Antiandrogen)
─ ___________ (Inhibitor of several steps in the biosynthesis of adrenal and gonadal steroids)
─ Aromatase inhibitors (Non-selective, selective)
Surgery /Chemotherapy for tumours
Hydrocortisone; L-thyroxine
Spironolactone; Ketoconazole
Management of PP 5/5
Peripheral PP:
Replacement therapy- CAH: Hydrocortisone, Hypothyroidism : L-thyroxine
Oversecretion of hormones
─Medroxyprogesterone (Antigonadotropic + inhibitor of biosynthesis of gonadal steroids)
─Cyproterone acetate (Antigonadotropic + antiandrogen)
─ Spironolactone (Antiandrogen)
─ Ketoconazole (Inhibitor of several steps in the biosynthesis of adrenal and gonadal steroids)
─ Aromatase inhibitors (Non-selective, selective) Surgery /Chemotherapy for tumours
