Puberty and menopause Flashcards
week 10
compare surge centre development in males and females
Males: NO development of SC as testosterone crosses BBB and converted into estradiol
Females: Development of SC as a-fetoprotein prevents estradiol crossing BBB
Describe the GnRH secretion in males and females pre and post-puberty.
Prepubertal
Pulses of LOW frequency and amplitude (tonic centre) (Both)
Post-pubertal
Pulses INCREASE in frequency and amplitude (Both)
Preovulatory burst in females ( surge centre)
Pre-pubertal behaviour of Hypothalamus vs Pubertal
Pre-pubertal
Tonic centre is highly SENSITIVE to negative feedback of estrogen and testosterone
Surge centre is responsive NOT YET to positive feedback of high levels of estrogen
Pubertal
Sensitivity declines, GnRH produced by tonic centre increases
Surge centre is responsive to positive feedback of high levels of estrogen
What are the three main causes of the changes in the hypothalamus during puberty?
Maturation of limbic system: removes initial inhibition
Nutritional stimuli: glucose, leptin and FA influences loss of sensitivity and initiates high freq GnRH pulses.
Threshold body weight: 47kg, as pregnancy and lactation = high metabolic cost, need certain level of fat reserve.
what early changes indicate onset of puberty?
Testicular/ scrotal growth and breast budding = onset
3 indicators of male fertility
Age of first ejaculation
Age when spermatoza first appear in ejaculate
Age when ejaculate contains threshold # sperm
3 indicators of female fertility
Age of menarche
Age of first ovulation
Age of dependeable ovulation in which female can support pregnancy
How do estrogen and testosterone production change in puberty?
Increased production (20 fold for E) due to decreased responsiveness of HP axis
What are the primary male sex characteristics
External genetalia
Accessory glands
Male genital ducts
What are the secondary male characteristics?
Body hair, voice, baldness
Increased skin thickness and muscle development
Behavior (aggression) and increased basal metabolism
What are the primary female sex characteristics?
Vagina, uterus, uterine tubes and external genitalia enlarge
Uterus and oviduct exhibit motility
Vaginal muvosa thickens
Watery cervical mucus
What are the secondary female sex characteristics?
Breast development and skin hydration
Long bone growth, pelvic widening and increased Ca resorption
Fat deposition (breast and hips)
Metabolism: increase HDL and decrease LDL
menopause and cause
Permanant cessation of mensuration from loss of ovarian folliclaur function
Loss of estrogen due to depletion of finite pool of follicles
criteria for menopause
12 months amenorrhea
What is the transitional period into menopause called and what are the symptoms of it?
Climacteric or perimenopause
symptoms
menstrual irregularities, hot flushes, mood disturbances, atrophy of repro tracts and breasts, bone changes (increased resporpton = osteoperosis) and CV changes (weight gain, increase LDL, HDL and increase risk of CV disease).
