190. Puberty Flashcards
Stage of pubic hair development in women:
The hair extends to the medial surface of the thighs and is distributed as an inverse triangle
Tanner 5
Stage with hair spreading to the inner thighs for men
Tanner 5
Breast bud develops
Tanner 2
Puberty in girls:
- average pubertal onset at __ years old
- Range of normal: 8-13 years old
- Menarche average at __ years old
- Peak growth rate occurs during Tanner __-__
- Menarche: Tanner __ breast development
10
12.5
2-3
4
Eating disorder that provides inadequate energy balance that suppresses production of GnRH, LH, and FSH
- no leptin activity
Anorexia nervosa
Pubic hair, axillary hair, body odor, and acne are signs of __
Girls: predominantly adrenal androgens
Boys: some from gonadal testosterone
Adrenarche
Stage of pubic hair development in women:
The hair spreads covering the pubis
Tanner 4
Mature adult phallus and scrotum
Tanner 5
Mutations in __ leads to hypogonadism then “reversal” in adulthood
Neurokinin B
In addition to neuropeptides, __ __ also regulates puberty
Need to be able to provide the necessary power to fuel someone to go through puberty
Energy balance
Stage of pubic hair development in women:
Sparse growth of long slightly pigmented hair straight or only slightly curly mainly along the labia
Tanner 2
Delayed puberty begins at > __ years in girls and > __ in boys
- delayed puberty is also defined by an elapsed time of 4-5 years from the onset of puberty to menarche or full testicular development
13
15
Mutation in Gs protein that leads to peripheral precocious puberty
Will see girls with recurring ovarian cysts
Cafe au lait spots
Fibrooptic dysplasia
McCune-Albright Syndrome
Acts upstream to release kisspeptin
- controls GnRH neurons –> encodes its receptor that then release LH and FSH
Important neuropeptide for puberty, not for reproduction
Neurokinin B
During infancy to late childhood/adolescence there is __ inhibition of the GnRH pulse generator
- initial “mini-puberty” after birth that lasts 6 months in boys and 12 months in girls then __ inhibition begins
CNS
GnRH-dependent (from hypothalamus) triggering of early puberty
- Idiopathic (more common in girls)
- CNS abnormalities
- Acquired (inflammation, surgery, trauma)
- Congenital (hydrocephalus, hypothalamic hamartoma)
- Tumors
- Chronic exposure to sex steroids (CAH)
Central Precocious Puberty
First signs of central puberty (Gonadarche):
- Girls: __
- Boys: __ __
Thelarche
Testicular enlargement
Enlargement of breast and areola with no separation of the contours
Tanner 3
Testis and scrotum enlarge further
- the penis grows mainly in length but also in breadth
Tanner 3
The hair spreads covering the pubis
Tanner 4
Most common mutation in Kallmann’s syndrome is in __
KAL1/ANOS1
__ GnRH-producing neurons:
- Leptin
- Kiss1, GPR54
- Neurokinin B
- Adequate energy balance
Excitatory
Neuropeptide that is released from adipose tissue when the body has enough body fat to provide the energy needed for puberty to take place
Leptin
Scrotum, testis, and penis grow further with development of the glans and further darkening of the scrotal skin
Tanner 4
Mutation in this maternally imprinted gene leads to precocious puberty
Protein blocks (inhibits) the release of GnRH from the hypothalamus, thus holding off the onset of puberty
MKRN3
Maturation of the hypothalamic-pituitary-adrenal axis
Adrenal androgens increase
- DHEA
- DHEA-S
- Androstenedione
Independent of puberty
Adrenarche
The hair is darker, coarser and curlier and spreads over the junction of the pubis
Tanner 3
Gonadarche
Transition period from the sexually immature state to the potentially fertile stage during which secondary sexual characteristics appear
Maturation of the hypothalamic-pituitary-gonadal axis
- increase in GnRH, LH, FSH, and testosterone or estrogen/estradiol
Puberty
Mature breast with slightly larger nipple and recession of the areola to the general contour of the breast with projection of the papilla only
Tanner 5
__ levels increase at pubertal onset
- administration of __ advances the timing of puberty
Kisspeptin
Delayed puberty:
__gonodatotropic = central, hypothalamic, pituitary
- Acquired - autoimmune, radiation, tumor
- Congenital - Kallmann, septo-optic dysplasia
- Malnutrition - Anorexia
- Chronic illness
- Excessive exercise
- Endocrinopathies - hyperprolactinemia, Cushing Syndrome
Hypo
Kiss1 protein activates __ which is needed to express GnRH neurons
Knockout mice have normal GnRH neurons, but gonadotropin deficiency and no puberty
Kiss1 receptor
Sparse growth of pigmented hair straight or slightly curly mainly at the base of the penis
Tanner 2
First menstrual period
Menarche
First appearance of breast tissue
Thelarche
Puberty in boys:
- Average onset at __ years old
- Range of normal onset: 9-15 years old
- Gynecomastia: Tanner 2-3
- Voice change: Tanner __-__
- Peak growth rate: Tanner __
- Spermarche: Tanner __-__
- Facial hair: Tanner __-__
11.5 Tanner 3-4 Tanner 4 Tanner 3-4 Tanner 4-5
Precocious puberty begins < __ years old in girls and < __ years in boys
8 (7 in black girls)
9
First appearance of pubic hair
Pubarche
__ GnRH-producing neurons:
- GABA
- B-endorphin
- MKRN3
Inhibitory
GnRH-independent triggering of early puberty
- Genetic (LH receptor-activating mutation, McCune-Albright Syndrome)
- Tumors (adrenal, ovarian, testicular, gonadotropin producing)
- Other (Hypothyroidism (Van Wyk Grumbach syndrome), exogenous sex steroids, ovarian cysts)
Boys w/ penis size enlargement w/o testicle enlargement
Peripheral precious puberty
Delayed puberty:
__gonadotropic = primary, gonadal
- Acquired - autoimmune, chemo, radiation, testicular torsion, infection (MUMPS)
- Congenital - Klinefelter Syndrome (47 XXY), gonadal dysgenesis
LH and FSH are high but T will be low
Hyper
Late bloomers suffer from
Constitutional delay of puberty
Stage of pubic hair development in women:
The hair is darker, coarser and curlier and spreads over the junction of the pubis
Tanner 3
The testis and scrotum enlarge and the skin of the scrotum shows some reddening and change in texture
Tanner 2
Gatekeepers of puberty
NKB and kisspeptin
Projection of areola and papilla to form a secondary mound above the level of the breast
Tanner 4
__ begins with an increase in GnRH pulsatility and subsequent increase in gonadotropin production
- increased frequency and amplitude, initially at night
Puberty
