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24 Cards in this Set
- Front
- Back
Define puberty |
Process of physical change by which a chids body becomes an adult body capable of reproduction - average age of onset is 10.7 years - average duration is 4.5 years - in the last 150 years, age of onset has declined by 4 years |
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What mechanisms are involved in puberty? |
sensitivity of Gonadostat to negative feed-back from oestrogen decreases central intrinsic inhibition decreases GABA and Neuropeptide Y released threshold level of Leptin required maturation of positive E2 feed back = LH surge |
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What are the sequence of events during puberty? |
maturation of hypothalamus stimulation of sex organs secretion of sex steroids sexual characteristics begin to develop sexual reproduction achieved |
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What neurohormonal changes take place at puberty |
hypothalamus: increased and more frequent pulses of GNRH released anterior pituitary: release FSH and LH gonads grow and release oestrogen and testosterone Oestrogen and testosterone produce body changes of female and male puberty maturation of positive feedback of E2 and LH |
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According to the British standards set after WWII, what events occur during puberty? |
1 Thelarche -breast development, average age 10 2 Adrenarche (pubarche) -pubic and axillary hair development, average age 10.5 3 Growth spurt - average age 11.4 4 Menarche -first menstrual period, average age 12.8 |
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What is the physiology of the changes that occur during pubery? |
accelerated growth - increased pulse amplitude of growth hormone influenced by oestrogen breast budding (Thelarche) - gonadal E2 pubic hair growth (pubarche) - adrenarche peak growth velocity onset of menstruation (menarche) - HPO axis - E2 stimulated endometrial proliferation |
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What other changes occur at puberty? |
White vaginal secretions (leukorrhea) acne widening of lower body (hips) due to increased body fat anemia fractures psychological issues - anxiety, issues of self esteem, depression behavioral issues - smoking, delinquent behavior |
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What factors affect the age of onset of puberty? |
genetic nutrition general health geographic location exposure to light psychological state |
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What is premature thelarche? |
breast developement (18 months to 4 years) with no other signs of pregnancy normal estradiol, LH, FSH, bone age, pelvis U/S |
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What is premature adrenarche? |
Isolated appearance of axillary and pubic hair bone age and normal 17-OHP DHEAS may be increased |
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Define delayed puberty? |
No secondary sexual charecteristics by 13/14 years OR No menarche by 16 years despite presence of secondary sexual charecteristics |
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What are the causes of delayed puberty? |
Hypergonadotrophic hypogonadism Hypogonadotrophic hypogonadism Eugonadism |
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How is delayed puberty managed? |
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What are some causes of delayed puberty with Eugonadism? |
Outflow tract obstruction Complete androgen insufficiency syndrome Ovulatory dysfunction - PCOS - thyroid dysfunction - hyperprolactinaemia |
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What are some causes of delayed puberty? |
Genetic causes - Turner Syndrome Hypothyroidism Ovarian causes Adrenal causes Hypothalamic/pituitary Chronic disease Nutrition, low leptin levels Outflow tract abnormalities |
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Define Precocious puberty |
Any pubertal signs before 7-8 (Caucasian) or 6-7 (African) Incidence 1:10 000 More common in girls than boys (23:1) Serious psychological problems |
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What hormonal changes lead to precocious puberty? |
Premature production of GNRH: LH and FSH Production of oestrogens or androgens from ovaries, adrenals Premature onset of secondary sexual characteristics |
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What are the types of precocious puberty? |
True/Central precocity Precocious pseudopuberty -isosexual or heteosexual Global precocious puberty Isolated precocious puberty |
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Name the causes of true/central precocity |
Idiopathic: 80% Constitutional - familial - onset just before 8 years CNS pathology - usually in girls <4 years Endocrine disrupters - organopesticides, phenols, phytoestrogens LH raised |
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Name the causes of precocious pseudopuberty |
GNRH independent - gonadotropin secreted independent of HPO axis ovarian cysts adrenal - masculinisation ectopic gonadotropin production Gonadal - tumours, McCune-Albright syndrome (cystic bones, cafe-au-lait spots) Exogenous endocrine disruptors Hypothyroid |
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What hormonal changes cause central precocious puberty? |
Gonadotropin secretion highly sensitive to negative feed back central inhibiting substance dominant suppression/damage to central inhibiting neural source induce onset of puberty reduced melatonin secretion by pineal gland |
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How do you examine a patient that you suspect of having precocious puberty? |
Height and weight Visual fields Skin anomalies External genitalia Enlarged thyroid |
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What are the aims of treatment of precocious puberty? |
Diagnose and treat intracranial disease Arrest maturation until normal pubertal age Attenuate established precocious features Maximize eventual adult height Avoid abuse and emotional problems Contraception Psychological support |
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How do we treat precocious puberty? |
GNRH analouges Progestins Monitor bone age Follow up 4 monthly Psychological counselling Support |