Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

rei written boards skory > Puberty > Flashcards

Puberty Flashcards

1
Q

Normal puberty order

A

Growth acceleration (not maximal) -> Thelarche -> Adrenarche/Pubarche -> Peak height velocity -> Menarche

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Etiology of thelarche

A

initial activity of HPO axis -> estrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Etiology of adrenarche/pubarche

A

Adrenal hormones -> hair growth

Zona reticularis: High P450c17, Low 3BHSD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How long between adrenarche and pubarche

A

2-3 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How long between peak height velocity and menarche

A

6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What mediates peak height velocity?

A

GH -> IGF-1 -> IGFBP-1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

First hormonal change in puberty

A

Nighttime LH pulses

  • One year before breast buds form, nocturnal LH pulses change
  • LH levels exceed those of FSH
  • LH amplitude increases x10, FSH amplitude increases x 2 -> decrease in the FSH/LH ratio
  • LH amplitude then rises to 20-40x greater than pre-pubertal levels
  • LH bioactivity increases through glycosylation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

First sign of male puberty

A

Testicular enlargement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Important neuropeptides/proteins responsible for rise in GnRH with puberty

A

Stimulatory: NPY (controversial), Leptin, Glutamate, Kisspeptin
Inhibitory: GABA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Premature puberty definition

A

Signs of secondary sexual development occurring before the age of eight years in girls and the age of nine years in boys are considered premature and warrant careful evaluation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How to differentiate between central and peripheral premature puberty

A

GnRH Stim test
• High LH after stim -> gonadotropin dependent (central)
• Low/normal LH after stim -> gonadotropin independent (peripheral)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Central (gonadotropin-dependent) premature puberty etiologies

A 
90% idiopathic
CNS lesions
Previous excess sex steroid exposure
Pituitary gonadotropin-secreting tumors
Secondary component of McCune-Albright syndrome
Poorly controlled CAH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Central premature puberty treatment

A

GnRH agonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Central premature puberty genetics

A
  • Gain-of-function mutations in kisspeptin 1 gene (KISS1) and its receptor (KISS1R)
  • Loss-of-function mutation in MKRN3 (imprinted gene in Prader-Willi critical region)
  • Loss-of-function mutation in DLK1 (delta-like 1 homolog)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

CNS lesions leading to central premature puberty

A

Hamartomas, CNS tumors, CNS radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Peripheral (gonadotropin-independent) premature puberty etiologies in females (2)

A 
Ovarian cysts – most common
Ovarian tumors (Granulosa cell > Sertoli/Leydig, pure Leydig, gonadoblastoma)
17
Q

Peripheral (gonadotropin-independent) premature puberty etiologies in males (3)

A

Leydig cell tumors
HCG-secreting germ cell tumors
Activating mutation in LH receptor

18
Q

Inheritance and pathophysiology of activating LH receptor mutation causing peripheral premature puberty

A

Autosomal dominant; premature Leydig cell maturation and testosterone secretion

19
Q

Presentation of activating LH receptor mutation causing peripheral premature puberty in boys

A

Precocious puberty with normal spermatogenesis but arrested

20
Q

Presentation of activating LH receptor mutation causing peripheral premature puberty in girls

A

Girls are not affected clinically, because (similar to hCG-secreting germ tumors) activation of both the LH and FSH receptors is required for estrogen biosynthesis

21
Q

Treatment of activating LH receptor mutation causing peripheral premature puberty

A

Androgen receptor antagonist (spironolactone) and aromatase inhibitor

22
Q

Peripheral (gonadotropin-independent) premature puberty etiologies in males and females

A
  • Primary hypothyroidism (also associated with delayed bone age)
  • Exogenous sex steroids/endocrine disruptors
  • Adrenal pathology
  • McCune-Albright syndrome
23
Q

McCune-Albright syndrome genetics and pathophysiology

A

Somatic mutation of the alpha subunit of the Gs protein (GNAS) that activates adenylyl cyclase
 Constitutively active adenylate cyclase converting ATP to cAMP
 cAMP activates protein kinase A
 Cause of precocious puberty = ovarian follicular cysts

24
Q

McCune-Albright syndrome presentation

A

Triad of peripheral precocious puberty, irregular café-au-lait (“coast of Maine”) skin pigmentation, and fibrous dysplasia of bone

25
Q

McCune-Albright syndrome treatment

A

Aromatase inhibitor - reduce the potential for compromised adult height due to early epiphyseal fusion from sustained estrogen exposure and reduce recurrent vaginal bleeding

26
Q

Premature pubarche definition

A

Isolated appearance of sexual hair (ie, sexual hair without breast development in girls, or without testicular enlargement in boys) before the age of eight years in girls and nine years in boys

27
Q

Premature pubarche etiology

A

Usually premature adrenarche; others: CAH, cushing’s, androgen secreting tumor

28
Q

Testing for etiology of premature pubarche

A

Bone age = single most important test (detect accelerated skeletal maturation/evidence of early virilization)
- If normal, likely idiopathic/not severe cause -> repeat bone age in 6 months
- If advanced, determine if bone age is proportionally advanced for child’s height
• If normal for height, virilizing disorder unlikely
• If advanced for height -> DHEAS, testosterone -> 17-OHP -> ACTH stim test

29
Q

Premature adrenarche definition

A

Very mild form of hyperandrogenism that is a variant of normal: it causes a slowly progressive, incomplete form of premature puberty; requires biochemical demonstration of a serum steroid pattern indicative of adrenarche before eight in girls and before nine in boys

30
Q

Testing for premature adrenarche

A

o DHEAS = best marker for presence of adrenarche (level > 40mcg/dL)
o If ACTH stim test performed, DHEA +/- 17OH-pregnenolone are typically increased for age

31
Q

Premature thelarche definition

A

o Isolated breast development, either unilateral or bilateral – typically not developing beyond Tanner stage 3
o Absence of other secondary sexual characteristics
o Normal height velocity for age (not accelerated)
o Normal or near-normal bone age

32
Q

Presentation of premature thelarche (timing)

A

Most cases of premature thelarche are idiopathic and present under two years of age (and may even start at birth).

33
Q

Indications for treatment of precocious puberty

A

o Predicted height below target
o Growth velocity > 6 cm/year
o Progression to next stage of development (thelarche, pubarche, menarche) in 3-6 months
o Bone age advance > 1 year or more

34
Q

Treatment monitoring in precocious puberty

A

Monitoring treatment (q3-6 months): Height measurement, bone age, serum LH levels < 3 IU/L

35
Q

Delayed puberty definition

A

Absence or incomplete development of secondary sexual characteristics bounded by an age at which 95 percent of children of that sex and culture have initiated sexual maturation

  • 12 years for girls (breast development being the first sign, Tanner stage B2)
  • 14 years for boys (increase in testicular size being the first sign, Tanner stage G2)
  • Pubarche not usually included in this definition because typically a sign of adrenarche, rather than true puberty
36
Q

Etiologies of delayed puberty

A

Primary (hypergonadotropic) hypogonadism (43%):
• Abnormal karyotype (26%): Turner’s, Klinefelter
• Normal karyotype/ovarian failure (17%)
Secondary (hypogonadotropic) hypogonadism (31%): [alpha subunit def]
• Constitutional delay of growth and puberty (10%)
• Isolated GnRH deficiency (Kallman’s)
• Other forms of hypo-hypo (poor nutrition, chronic disease, hypothyroid, excessive exercise)
• Hypothalamic or pituitary disease (tumors, esp craniopharyngioma; prolactinoma, injury, etc)
Eugonadism (26%): MRKH (14%), septum, hymen, AIS

37
Q

Presentation of inactivating LH receptor mutation in males

A

Azoospermia 2/2 leydig cell hypoplasia

38
Q

Presentation of inactivating LH receptor mutation in girls

A

Primary amenorrhea (hypo/hypo), with normal breast/hair

rei written boards skory (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions