Male reproductive endocrinology Flashcards
what are the requirements for normal function
gonadal and reproductive system development
intact reproductive hormone production
puberty
spermatogenesis
normal spermatozoa
erectile function
non-obstructive anatomy
what are hormones key for
during development of the testicular reproductive system
during puberty and spermatogenesis
during sperm production and erectile function
what key changes occur in foetal life
process of sex determination (XY karyotype)
formation of testis (largely independent of hormones)
testosterone is important once testis have formed for activity within them and for masculinisation of the foetus
what controls the development of the male reproductive system
under control of the hypothalamic-pituitary-gonadal (HPG) axis
active during foetal development and lasts until around birth
what is the function of anti-mullerian hormone
induces regression of mullerian ducts (oviducts, uterus, vagina)
produced by testicular sertoli cells
what is the function of testosterone in foetal life
maintains the male reproductive structures
what occurs during infancy
HPG axis is reactivated (lasts ~3-6months)
called ‘mini-puberty’
what is ‘mini-puberty’ important for
development of external genitalia
window for investigating reproductive function
what occurs during childhood
HPG axis is inactive
no testosterone
no sperm
prepubertal testis do have germ stem cells (sperm), sertoli cells (fertility) and leydig cells (puberty and testosterone)
what occurs during puberty
HPG axis is activated
responsible for initiation of spermatogenesis and secondary sex characteristics
normally occurs around 9-14
what is pubertal staging
assessment of pubertal development
focuses on development of axillary and pubic hair, development of external genitalia and testicular volumes
when is the GnRH stimulation test used
when there are concerns about puberty or delay in testicular function
what occurs throughout adulthood
maintenance of secondary sex characteristics and of testosterone production
continuous spermatogenesis and sperm production is the goal
HPG axis is super important for this
what are environmental disorders
cryptorchidism (undescended testes)
hypospadias (abnormality of the urethral opening)
infertility
testicular cancer
hypogonadism
collectively known as testicular dysgenesis syndrome
what are genetic disorders
ambiguous genitalia
gonadal tumours
hypogonadism
infertility
collectively referred to as disorders of sex development
what is a karyotype used for
determine if the patient is an undervirilised XY or a virilised XX, or any other type
what is an ultrasound/MRI used for
determine what the ambiguous structures are
location (if gonads in inguinal/scrotum region indicates testes, if in abdomen indicated ovaries)
determine what hormones are being produced from the structures
if uterus is absent, indicates testes
can do a laparoscopic surgery for further investigation
what is the function of testosterone
testosterone activates androgen receptors leading to gonadal descent
5alpha-reductase converts testosterone to dihydrotestosterone (DHT) which leads to development of external genitalia
what can abnormalities of hormone pathways lead to
all types of disorders, particularly cryptorchidism and ambiguous genitalia
how is genetics tested
sequence the androgen receptor gene on the X-chromosome,
if mutation is identified in the AR diagnosis is (partial) androgen insensitivity syndrome (PAIS)
what are the stages of puberty
stage 1 is completely pre-pubertal
stage 5 is normal adult male development
what are some final diagnostic tests
GnRH stimulation test, also production of LH, FSH and testosterone
scrotal ultrasound - testicular masses, epididymal cysts, varicocele
tumour markers - hCG, AFP, LDH
what can cancer treatment as a boy cause
chemo and radiotherapy can lead to delayed puberty and eventual hypogonadism
can also cause infertility
what can be done for cancer
surgery - orchidectomy (removal of a testis)
pathology - seminoma vs non-seminoma
staging of cancer
where does the risk of infertility come from in cancer treatment
TDS or treatment
can do sperm banking before treatment
what is hypogonadotropic hypogonadism
decreased LH, FSH and testosterone
something in brain has been affected
what are the diagnoses for hypogonadotropic hypogonadism
delayed puberty
congenital hypog hypog
brain tumour
radiotherapy
kallmann’s syndrome (if they cant smell)
what is the treatment for hypog hypog
testosterone and gonadotrophins to induce puberty and fertility
what is hypergonadotrophic hypogonadism
increased LH and FSH but decreased testosterone
what are the diagnoses for hyper hypog
Klinefelter syndrome
DSD/gonadal dysgenesis
chemo/radiotherapy
