11: Male Reproductive Physio Clinical Correlations Flashcards
What does 5a-reductase deficiency cause in fetus?
Ambiguous external genitalia
Two conditions that depend on DHT and what treatment can be used for both
BPH and male pattern baldness -> treatment is 5a-reductase inhibitors
T deficiency at 2-3rd month of gestation
Varying degrees of ambiguity of male genitalia
T deficiency at 3rd trimester
Problems with testicular descent + micropenis
T deficiency at puberty
Poor secondary sexual development, eunuchoid features
Eunuchoidism
persistence of prepubertal characteristics, and often presence of characteristics of opposite sex
T deficiency post-puberty
Decreased libido, ED, decreased facial and body hair, low energy, infertility
Two forms of male hypogonadism
Kallman’s syndrome, Klinefelter syndrome
Kallman’s syndrome mechanism
GnRH neurons fail to migrate into hypothalamus
Presentation of Kallman’s syndrome
Delayed or absent puberty, impaired sense of smell, occurs more often in males
A form of hypogonadotropic hypogonadism
Kallman’s syndrome
Klinefelter syndrome mechanism
Seminiferous tubule dysgenesis -> low androgens and high gonadotropins
Genotype of Klinefelter syndrome
47, XXY
Phenotype of Klinefelter syndrome
Appear male at birth, at puberty have increased gonadotropins but fail to induce testicular growth and spermatogenesis -> infertility
By age 80, how many males have BPH?
80%
Presentation of BPH
urinary frequency, urgency, nocturia, difficulty initiating and maintaining urinary stream, feeling post-void fullness in bladder, dribbling urine
What causes BPH?
Not a higher level of DHT, but higher levels of DHT receptors on the prostate
Treatment for male pattern baldness and benign prostatic hyperplasia
5a-reductase inhibitor
Treatment for prostate cancer
Androgen receptor antagonists, radiotherapy, prostatectomy
What do testis tumors usually produce?
Large amounts of T
What do germinal epithelial tumors in testes usually produce?
No hormones
Andropause
As men age, gonadal sensitivity to LH decreases + androgen production drops -> LH and FSH rise
Testosterone levels at age 40+ and what this causes
Slowly decrease after age 40 -> decreased bone formation, muscle mass, facial hair, appetite, libido
When does sperm production begin to decline?
Age 50
