Physiology of Puberty COPY Flashcards
Define Puberty
- The stage of physical maturation in which an individual becomes physiologically capable of pro-creation (sexual reproduction)
Physical Changes in Puberty
- … spurt
- … … characteristics
- M…/s…
- Growth spurt
- Secondary sex characteristics
- Menarche/spermatogenesis
Physical Changes in Girls
- … …
- 8 - 14 yrs
- 6 - 10 cm / yr peak
- 2.5 yrs duration
- … … (…)
- 8 - 13 yrs ( 11 yrs )
- Usually the first sign
- … … (…)
- 9 - 13 yrs
- 1st Pubertal Sign in …%
- … … (…)
- 9.5 - 15 yrs
- May follow Menarche
- … (…)
- 10 - 16 yrs ( 13 yrs )
-
GROWTH SPURT
- 8 - 14 yrs
- 6 - 10 cm / yr peak
- 2.5 yrs duration
-
BREAST GROWTH (Thelarche)
- 8 - 13 yrs ( 11 yrs )
- Usually the first sign
-
PUBIC HAIR (Pubarche)
- 9 - 13 yrs
- 1st Pubertal Sign in 25%
-
AXILLARY HAIR (Adrenarche)
- 9.5 - 15 yrs
- May fllow Menarche
-
MENSTRUATION (Menarche)
- 10 - 16 yrs ( 13 yrs )
Endocrine Changes in Puberty
- …-…-… synchrony – established in … life
- Until … – neural mechanisms suppress … release
- At …-… yrs – pulsatile nocturnal … release

- H-P-G synchrony – established in fetal life
- Until puberty – neural mechanisms suppress GnRH release
- At 6-9 yrs – pulsatile nocturnal GnRH release
Endocrine Changes in Puberty
- Pulsatile … release (nocturnal) every … - … min - 6 to 9 years
- increased … leads to increased … and increased …
- …/… become sensitized to the effects of these
- Final phase: development of …/… feedback mechanism
- … stimulates the adrenals – … & … hair
- Pulsatile GnRH release (nocturnal) every 90-120 min - 6 to 9 y
- increased GnRH leads to increased FSH and increased LH
- Ovaries/testes become sensitized to the effects of FSH and LH
- Final phase: development of positive/negative feedback mechanism
- ACTH stimulates the adrenals – Pubic & Axillary hair
Testes
- Production of … (…)
- … cells under FSH control
- Production of … (Testosterone)
- … cells under LH control
- …% from testes, …% from adrenals
- Testosterone in blood – converted to … in the target organs
- Production of gametes (sperms)
- Sertoli cells under FSH control
- Production of androgens (Testosterone)
- Leydig cells under LH control
- 95% from testes, 5% from adrenals
- Testosterone in blood – converted to DHT in the target organs
The Ovarian Cycle
- … phase
- Initially E rises (…) with LH surge in …
- … occurs
- … phase
- … feedback after ovulation
- No further … in the same cycle

- Follicular phase
- Initially E rises (FSH) with LH surge in mid cycle
- Ovulation occurs
- Luteal phase
- Negative feedback after ovulation
- No further ovulation in the same cycle

What is this showing?

Endometrial cycle
Age of Menarche
- Related to general health, genetic and nutritional factors
- Mean age is … at a rate of … months per decade
- Mean age in 1840 = … y; 1990 = … y
- One in … girls now reaches menarche while at primary school
- Body … and % … is also important
- Mean weight at menarche is …kg
- …-…% fat
- …, patients with … – late onset
- Related to general health, genetic and nutritional factors
- Mean age is falling at a rate of 4 months per decade
- Mean age in 1840 = 16.5 y; 1990 = 12.8 y
- One in 8 girls now reaches menarche while at primary school
-
Body weight and % fat is also important
- Mean weight at menarche is 47.8kg
- 16-24% fat
- Athletes, patients with anorexia – late onset
Adrenarche
- … … – responsible for axillary and pubic hair
- … stimulates zona … of adrenal cortex
- DHEAS & Androstenedione
- Girls – starts by …, adequate levels by …
- Boys – starts by …, adequate levels by …
- Adrenal androgens – responsible for axillary and pubic hair
- ACTH stimulates zona reticularis of adrenal cortex
- DHEAS & Androstenedione
- Girls – starts by 6, adequate levels by 8
- Boys – starts by 8, adequate levels by 10
Define Adrenarche
- Adrenarche refers to the time during puberty when the adrenal glands increase their production and secretion of adrenal …
- Plasma concentrations of dehydroepiandrosterone (…) and DHEA-sulfate(s), the most important adrenal androgens, begin to increase in children by approximately … to …years.
- However, the signs of adrenarche, such as … and … … development, a…, and body …, do not typically occur until … to ….
- Adrenarche refers to the time during puberty when the adrenal glands increase their production and secretion of adrenal androgens. Plasma concentrations of dehydroepiandrosterone (DHEA) and DHEA-sulfate(s), the most important adrenal androgens, begin to increase in children by approximately 6 to 8 years. However, the signs of adrenarche, such as pubic and axillary hair development, acne, and body odor, do not typically occur until early to midpuberty.
Chronological Order of Puberty - Girls
- … ….
- … development
- … hair
- … hair
- …
- Growth spurt
- Breast development
- Pubic hair
- Axillary hair
- Menarche
Chronological Order of Puberty - Boys
- … volume
- … length
- … hair
- … …
- … / … hair
- … voice
- Testicular volume
- Penile length
- Pubic hair
- Growth spurt
- Axillary / Facial hair
- Deep voice
For each row, what is the subtitle?

- Beginning of puberty
- Growth Spurt
- Years of Puberty
- Menarche/Voice Deepening

Disorders of Puberty - Early or Precocious
- Girls – under … yrs
- Boys – under … yrs
- Girls – under 8 yrs
- Boys – under 9 yrs
Disorders of Puberty - Delayed
- Girls – over … yrs
- Boys – over … yrs
- Girls – over 14 yrs
- Boys – over 14 yrs
Precocious Puberty
- … or … puberty
- Presence of true pubertal features at an … & … age
- Central or True precocious puberty
- … dependent
- Peripheral or Pseudo-precocious puberty
- … independent
- Central or True precocious puberty
- Normal variants
- … T…
- … A…
- Early or Premature puberty
- Presence of true pubertal features at an young & inappropriate age
- Central or True precocious puberty
- Gonadotrophin dependent
- Peripheral or Pseudo-precocious puberty
- Gonadotrophin independent
- Central or True precocious puberty
- Normal variants
- Premature Thelarche
- Premature Adrenarche
Concerns raised by early onset puberty
- Possible underlying sinister cause
- … – up to …%
- … & …-… upheaval at an inappropriately young age
- Early cessation of … leading to decreased final … …
- Possible underlying sinister cause
- Boys – upto 80%
- Emotional & pyscho-social upheaval at an inappropriately young age
- Early cessation of growth leading to decreased final adult height
What is the Diagnosis?
-
Emileigh, 14 months
- Blood clots in nappy
- Bilat breast buds
- Ht & Wt >97th centile
- LH 2.2, FSH 3.2,
- 17β estradiol 432
- Uterus – enlarged
- Bone age – 2.8 yrs
- MRI scan shown

- Hypothalamic Hamartoma - premature true puberty - LH and FSH should be undetectable, uterus enlarged, blood clots in nappy, bones advanced (oestrogen), Breast buds

Precocious Puberty - Central (testing / treatment)
- Long acting … analog therapy
- Sustained supra-physiological … levels
- Paradoxical cessation of … release
- Stops further … …
- Pubertal progression resumes when treatment stopped (at …-… yrs)
- Long acting LHRH analog therapy
- Sustained supra-physiological LHRH levels
- Paradoxical cessation of gonadotrophin release
- Stops further pubertal progression
- Pubertal progression resumes when treatment stopped (at 10-12 yrs)
Normal Variants - Precocious Puberty
- Premature …
- Isolated … development
- Usually seen in children
- Premature …
- Isolated … … development
- Caution: first sign of … in some
- Premature thelarche
- Isolated breast development
- Usually seen in children <2-3 yrs of age
- Premature adrenarche
- Isolated pubic hair development
- Caution: first sign of puberty in some
Pseudo-precocious puberty - Females / Males
-
Females:
- Iso-sexual or feminising
- Causes - MAS - stands for… , O…/A…
- Hetero-sexual or masculinising
- C.., O../A…
- Iso-sexual or feminising
-
Males:
- Iso-sexual or masculinising
- Causes - C…, A…l/L… cell …
- Hetero-sexual or feminising
- A…
- Iso-sexual or masculinising
- Females:
- Iso-sexual or feminising
- Causes - MAS - stands for McCune-Albright syndrome , Ovarian/Adrenal
- Hetero-sexual or masculinising
- CAH, Ovarian/Adrenal
- Hetero-sexual or masculinising
- CAH, Ovarian/Adrenal
- Iso-sexual or feminising
- Males:
- Iso-sexual or masculinising
- Causes - CAH, Adrenal/Leydig cell tumour
- Hetero-sexual or feminising
- Adrenal
- Iso-sexual or masculinising
What is the diagnosis?
- Mairna, 6 yrs
- Obese
- Pubic hair stage 2
- No breast bud
- LH <1, FSH 1.4,
- 17β estradiol 32
- Steroid profile
Congenital Adrenal Hyperplasia
- Congenital adrenal hyperplasia (CAH) is a group of autosomal … disorders characterized by impaired … synthesis.
- It results from the deficiency of one of the … enzymes required for the synthesis of … in the adrenal ….
- Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders characterized by impaired cortisol synthesis.
- It results from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cortex.

This is showing … biosynthesis

Steroid biosynthesis
Delayed Puberty
- Absence of … pubertal onset at an … age
- Not necessarily lack of … in a …
- …-files – very important
- Normal …
- Constitutional … & … delay
- Absence of true pubertal onset at an appropriate age
- Not necessarily lack of periods in a girl
- X-files – very important
- Normal variant
- Constitutional growth & pubertal delay
Concerns raised by delay in Puberty
- Possible sinister underlying cause
- … that puberty will never occur
- Emotional and psychosocial upset of …, specially when associated with … stature
- Long term sequelae: Reduced … …
- Possible sinister underlying cause
- Fear that puberty will never occur
- Emotional and psychosocial upset of immaturity, specially when associated with short stature
- Long term sequelae: Reduced bone mineralization
What is the diagnosis?
- Steven, 16 yrs
- No pubertal progress
- Learning difficulties
- Tall, 98th centile
- PH-2, G-2, TV-6ml
- LH 12, FSH 16, T 40
- Bone age – 14.5 yrs
Klinefelter Syndrome

Klinefelter Syndrome
- 1 in … … infants
- 47 … / Multiple …
- … problems
- … deficiency
- …spermia / …
- (Micro … -> Sex change)
- Lifelong … replacement therapy
- 1 in 1000 male infants
- 47 XXY / Multiple X
- Behavioural problems
- Androgen deficiency
- Azoospermia / Infertility
- (Micro genitalia -> Sex change)
- Lifelong testosterone replacement therapy

What is the diagnosis?
- Rosie, 12 yrs
- Short Stature
- No pubertal onset
- Recurrent ear infections
- Increased carrying angle
- Widely spaced nipples
- LH 56, FSH 95,
- 17β estradiol 45
- Karyotype
Turner Syndrome

Turner Syndrome
- 1 in … live … births
- Triad - … stature, … gonads, primary …
- … features – Webbing of neck, cubitus valgus
- … of aorta, horse shoe …
- Early clue - L…
- Surprisingly … !!!
- Turner …

- 1 in 2000 live female births
- Triad - Short stature, streak gonads, primary amenorrhoea
- Dysmorphic features – Webbing of neck, cubitus valgus
- Coarctation of aorta, horse shoe kidneys
- Early clue - Lymphedema
- Surprisingly normal!!!
- Turner Mosaic
Turner Syndrome
- Exclude co-existing … anomalies
- … Hormone therapy
- Pubertal induction + ongoing …
- Active monitoring to detect …
- Assisted …
- Exclude co-existing congenital anomalies
- Growth Hormone therapy
- Pubertal induction + ongoing HRT
- Active monitoring to detect co-morbidities
- Assisted conception
What is the diagnosis?
- James, 15 yrs
- Absent smell sensation
- PH-1, G-1, AxH-1, TV-2ml each
- LH <1, FSH 1.2, T 0.8
- LHRH stimulation test – peak LH remained <1
- HCG stimulation test – min. increase in T
- MRI scan – Normal
- Kallman gene analysis – Negative
- Lifelong Testosterone replacement therapy
Gonadotrophin deficiency
Normal Variant - Delayed puberty
- Constitutional delayed growth & puberty
- More common in …
- … & … in school days
- … onset of puberty
- … age delayed slightly
- … history – often present
- Normal … …
- Pubertal … – sometimes necessary
- Constitutional delayed growth & puberty
- More common in boys
- Small & Short in school days
- Late onset of puberty
- Bone age delayed slightly
- Family history – often present
- Normal adult height
- Pubertal induction – sometimes necessary