Term
| why does exogenous testosterone shut down spermatogenesis? |
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Definition
| b/c it will shut off LH/FSH via negative feedback |
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Term
| what contributing factors can lead to testosterone insufficiency? |
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Definition
| klinefelter's/kallman's, testicular injury, mumps, orchiectomy, pituitary tumors, and pelvic/head irradiation |
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Term
| what is the avg decline in serum testosterone levels in older men per year? |
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Definition
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Term
| what is primary hypogonadism? |
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Definition
| when the gonadotropins (FSH/LH) are high (elevated) but testosterone is low due to leydig cell/testicular dysfunction. sertoli cell function may also be impaired = decreased sperm production. |
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Term
| can chronic illness, obesity, and medications lower testosterone levels? |
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Definition
| yes. obesity lowers sex hormone binding globulin and thus lowers testosterone. |
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Term
| what are s/s for androgen deficiency in men? |
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Definition
| incomplete sexual development, aspermia, eunuchoidism, decreased libido, decreased spontaneous erections, breast discomfort/gynecomastia, loss of body hair, small/shrinking testes, inability to father children, height loss, reduced muscle bulk/strength, hot flashes, sweats |
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Term
| what are possible causes of hypogonadism? |
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Definition
| congenital: cryptorchism, klinefelters (XXY), kallman's (inability to smell), sickle cell (causes problem in pituitary), and defects in the androgen receptor. acquired: radiation, trauma, age, mumps orchitis, alchohol, medications, obesity, pituitary disorder, and autoimmune syndromes. |
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Term
| what characterizes the process of obtaining testosterone levels? |
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Definition
| testosterone is secreted w/diurnal variation, therefore its levels will be highest in the morning. total testosterone which includes that bound to sex hormone binding globulin is affected by this variation. free testosterone is affected less by this variation. |
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Term
| what are the pubertal changes due to testosterone secretion? |
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Definition
| external genitalia maturation, hair growth, linear growth, accessory sex organs (prostate), voice, and psyche (more aggressive) |
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Term
| what is the normal range for testosterone? |
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Definition
|
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Term
| what is the normal size for male testes? |
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Definition
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Term
| what is a common sign of klinefelters (seminiferous tubule dysgenesis)? |
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Definition
| the common sign is: small firm testes due to leydig cell fibrosis/hyalinization. other signs of klinefelters (XXY) include: azoospermia, gynecomastia, mental abnormalities, and elevated FSH, LH (primary gonadal failure). |
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Term
| what is a sign of kallmans (lack of GnRH)? |
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Definition
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Term
| what chronic diseases can cause hypogonadism? |
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Definition
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Term
| what is the most common cause of organic impotence? |
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Definition
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|
Term
| what drugs can affect libido? |
|
Definition
| alcohol, tranquilizers, sedatives, opiates, and antihypertensives |
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Term
| what is treatment for klinefelters? |
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Definition
| correct androgen deficiency, correct gynecomastia, and psychiatric care (may be retarded, frustrated, have low libido) |
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Term
| what is myotonic dystrophy? |
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Definition
| another form of primary gonadal failure due to neuromuscular disease. these pts will also have premature baldness, mental retardation, lenticular opacities, small atrophic testes, and normal pubertal development. sometimes this requires a testicular bx to dx and their testosterone level should be low. generally androgen therapy is not given. |
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Term
| what is a common cause of adult infertility? |
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Definition
| seminiferous tubular failure - a possible side effect of epididymitis or orchitis |
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|
Term
| can irradiation cause hypogonadism? |
|
Definition
| yes - this may lead to seminiferous tubule damage |
|
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Term
| what is noonan's syndrome? |
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Definition
| a pt who looks like they have turners (short, webbed neck, low set ears, shield-like/flat chest, ptosis of the lids, pulmonic stenosis, and cubitus valgus) - but have a normal karyotype |
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Term
| what are the obesity-hypogonadism syndromes? |
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Definition
| laurence-moon biedl: retinitis pigmentosa, polydactylly, and mental retardation. alstrom syndrome: retinitis pigmentosa, nerve deafness, DM, and primary gonadal syndromes. prader-wili syndrome: *hypotonia", mental retardation, and hyperphagia |
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Term
| what is tx for adult leydig cell failure? |
|
Definition
| testosterone/pyschiatric tx |
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|
Term
| what is tx for cryptorchidism? |
|
Definition
| orchiopexy surgery and HCG (acts like LH and will descent testes) |
|
|
Term
| what is vanishing testes syndrome? |
|
Definition
| testes that recede back into the pelvis |
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Term
| what characterizes the *hypo*gonadotrophic hypogonadism syndromes? |
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Definition
| classic: kallman's w/tall stature (GH still secreted), anosmia/hyposmia, eunuchoid habitus, tall stature, and low LH/FSH/testosterone (problem in the pituitary/hypothalamus). these pts are treated w/testosterone + HCG. another example of this: postpubertal pituitary failure (can be selective or panhypopituitarism) |
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Term
| what characterizes the *hyper*gonadotrophic hypogonadism syndromes? |
|
Definition
| klinefelters (problem in the testes) |
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|
Term
| what are some relative contraindications to testosterone administration? |
|
Definition
| elevated hematocrit (stroke risk), CHF, and rising PSA |
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|
Term
| can testosterone increase risk of breast CA? |
|
Definition
| yes - testosterone is converted to estradiol and may mediate breast cancer |
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|
Term
| why does gynecomastia occur? |
|
Definition
| a disruption of the testosterone/estrogen ratio (liver disease, medication, hyperthyroidism, refeeding after starvation, etc) |
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