Physiology of puberty in normal humans.pdf

Puberty
Puberty
Dr. Ashraf Fouda
Damietta General Hospital

PUBERTY
PUBERTY
It is a physiological
It is a physiological
phase lasting
phase lasting
2 to 5 years
2 to 5 years,
,
during which the
during which the
genital organs mature
genital organs mature

Manifestations of puberty
Manifestations of puberty
in the female include
in the female include
:
:
1.
1. Menarche,
Menarche,
2.
2. Appearance of secondary sex
Appearance of secondary sex
characters,
characters,
3.
3. Physical development and
Physical development and
4.
4. Psychological changes.
Psychological changes.

Secondary sex characters
Secondary sex characters
include
include
:
:
development of the
development of the
breast, appearance of
breast, appearance of
pubic and axillary
pubic and axillary
hair.
hair.

The first sign of pubertal
The first sign of pubertal
development is usually breast
development is usually breast
growth
growth (thelarche),
(thelarche), followed by
followed by
appearance of pubic hair
appearance of pubic hair
(pubarche),
(pubarche), then
then (
(axillary hair)
axillary hair),
,
then
then (
(menarche)
menarche).
.
The mean interval between breast
The mean interval between breast
budding and menarche is
budding and menarche is 2.5 years
2.5 years
with a standard deviation of about
with a standard deviation of about
one year
one year.
.

Adrenarche
Adrenarche
means
means increased activity of the
increased activity of the
suprarenal cortex at puberty
suprarenal cortex at puberty
with increased production of
with increased production of
adrenal androgens which lead
adrenal androgens which lead
to appearance of pubic and
to appearance of pubic and
axillary hair.
axillary hair.

Cause of puberty
Cause of puberty
:
:
During childhood , the
During childhood , the hypothalamus is
hypothalamus is
extremely sensitive to the negative feedback
extremely sensitive to the negative feedback
exerted by the small quantities of estradiol
exerted by the small quantities of estradiol
& testosterone produced by the child's
& testosterone produced by the child's
ovaries .
ovaries .
As puberty approaches ,
As puberty approaches , the sensitivity of
the sensitivity of
the hypothalamus is decreased
the hypothalamus is decreased and
and
subsequently
subsequently , it
, it increase the pulsatile
increase the pulsatile
GnRH secretion .
GnRH secretion .

The anterior pituitary
The anterior pituitary
responds by progressive
responds by progressive
secretion of
secretion of FSH and LH
FSH and LH
associated with
associated with
increased secretion of
increased secretion of
growth hormone
growth hormone .
.

The
The ovaries respond
ovaries respond to
to
the increase
the increase
Gonadotrophin secretion
Gonadotrophin secretion
by
by follicular
follicular
development & estrogen
development & estrogen
secretion .
secretion .

Estrogen
Estrogen causes development
causes development
of the genital organs and the
of the genital organs and the
appearance of the secondary
appearance of the secondary
sexual characters .
sexual characters .
With increased estrogen
With increased estrogen
secretion ,
secretion , menarche
menarche and
and
cyclic estrogen secretion
cyclic estrogen secretion
occurs .
occurs .

Factors affecting the initiation
Factors affecting the initiation
of pubertal development
of pubertal development
:
:
1 -
1 - Height and weight ratio
Height and weight ratio (nutritional
(nutritional
factors).
factors).
2 - Maturation of the
2 - Maturation of the hypothalamus
hypothalamus .
.
3 - Increased
3 - Increased neurotransmitter output
neurotransmitter output
in CNS .
in CNS .
4 - Onset of
4 - Onset of adrenal androgen
adrenal androgen activity
activity

Deposition of SC fat
Deposition of SC fat
:
:
17%
17% to menstruate
to menstruate
&
&
22%
22% to ovulate
to ovulate

Genital organs changes
:
:
 Mons pubes, labia majora & minora
Mons pubes, labia majora & minora:
:
increase in size.
increase in size.
 Vagina:
Vagina:
1.
1. length:
length: increase, appearance of the
increase, appearance of the
rugae
rugae
2.
2. Epithelium:
Epithelium: thick, stratified
thick, stratified
squamous., containing glycogen
squamous., containing glycogen
3.
3. pH:
pH: acidic.
acidic.

Uterus
Uterus:
:
enlarge, Uterus / Cervix :2 / 1
enlarge, Uterus / Cervix :2 / 1
Ovaries:
Ovaries:
1.
1.Increase in size, almond shape
Increase in size, almond shape
2.
2.300 thousands primary follicle at
300 thousands primary follicle at
menarche ( 2 million at birth)
menarche ( 2 million at birth)
:
:

Adolescence
Adolescence
:
:
Is the period of life during which
Is the period of life during which
the child becomes an adult person
the child becomes an adult person
i.e. the physical , sexual and
i.e. the physical , sexual and
psychological development are
psychological development are
complete .
complete .
Puberty represents the first part
Puberty represents the first part
of adolescence .
of adolescence .

Abnormalities of puberty
Abnormalities of puberty
1 -
1 - Precocious puberty .
2 - Delayed puberty .
3
3 - Growth problems :
during adolescence e.g. short
during adolescence e.g. short
stature or tall stature , marked
stature or tall stature , marked
obesity and menstrual disorders
obesity and menstrual disorders
at puberty .
at puberty .

FEMALE
FEMALE
PRECOCIOUS
PRECOCIOUS
PUBERTY
PUBERTY

Definition
Definition
:
:
It means menarche or
It means menarche or
appearance of any of
appearance of any of
the secondary sexual
the secondary sexual
characters before the
characters before the
age of
age of 8 years.
8 years.

Types
Types
:
:
1
1 -
- True
True precocious puberty .
precocious puberty .
2
2 -
- False
False
(pseudo-precocious puberty).
(pseudo-precocious puberty).
3
3 -
- Incomplete
Incomplete precocious
precocious
puberty .
puberty .

1
1
.
.
True (central ,cerebral)
True (central ,cerebral)
precocious puberty
precocious puberty
.
.
It is due to increased
It is due to increased
production of pituitary
production of pituitary
gonadotrophins.
gonadotrophins.

2
2
.
.
False (peripheral) precocious puberty
It is of peripheral origin.
It is of peripheral origin.
It is
It is due to secretion of sex
due to secretion of sex
hormones
hormones;
; (estrogen or androgen)
(estrogen or androgen)
which is not dependent on
which is not dependent on
pituitary gonadotrophins as in
pituitary gonadotrophins as in
case of estrogenic or androgenic
case of estrogenic or androgenic
ovarian tumors.
ovarian tumors.

False precocious puberty may be
False precocious puberty may be
isosexual or heterosexual.
isosexual or heterosexual.
A girl who feminizes early is defined as
A girl who feminizes early is defined as
having
having isosexual precocious puberty
isosexual precocious puberty.
.
A girl who virilize early is defined as
A girl who virilize early is defined as
having
having heterosexual precocious puberty
heterosexual precocious puberty.
.
(female pseudohermaphrodite)
(female pseudohermaphrodite)
2
2
.
.

3
3
.
.
Incomplete precocious puberty
In this case only one pubertal change
In this case only one pubertal change
as
as breast development
breast development is present
is present
before the age of 8 years without the
before the age of 8 years without the
presence of any other pubertal
presence of any other pubertal
changes and in absence of increased
changes and in absence of increased
estrogen production.
estrogen production.
The other pubertal changes occur at
The other pubertal changes occur at
the normal age.
the normal age.

Incomplete forms of precocious
puberty include
puberty include premature
premature
thelarche
thelarche (unilateral or
(unilateral or
bilateral),
bilateral), premature pubarche
premature pubarche
and
and premature adrenarche
premature adrenarche
with appearance of pubic and
with appearance of pubic and
axillary hair.
axillary hair.
3
3
.
.

Etiology of precocious puberty
1.Constitutional or idiopathic:
1.Constitutional or idiopathic:
In most cases of precocious puberty
In most cases of precocious puberty
(90%)
(90%) , no cause is found.
, no cause is found.
For some unknown reason the
For some unknown reason the
hypothalamus stimulates the pituitary
hypothalamus stimulates the pituitary
gland to secrete its gonadotrophic
gland to secrete its gonadotrophic
hormones.
hormones.
There is normal menstruation and
There is normal menstruation and
ovulation.
ovulation.
Pregnancy can occur at young age.
Pregnancy can occur at young age.

2.
2. Organic lesions of the brain:
Organic lesions of the brain:
The next common cause.
The next common cause.
Organic lesions
Organic lesions affecting the midbrain,
affecting the midbrain,
hypothalamus, pineal body, or pituitary gland
hypothalamus, pineal body, or pituitary gland
may lead to premature release of pituitary
may lead to premature release of pituitary
gonadotrophins.
gonadotrophins.
Examples
Examples include traumatic brain injury,
include traumatic brain injury,
meningitis, encephalitis, brain abscess, brain
meningitis, encephalitis, brain abscess, brain
tumor as glioma, craniopharyngioma, and
tumor as glioma, craniopharyngioma, and
hamartomas.
hamartomas.

3. McCune-Albright syndrome.
3. McCune-Albright syndrome.
4. Adrenal causes:
4. Adrenal causes:
(a) Hyperplasia, adenoma, or
(a) Hyperplasia, adenoma, or
carcinoma of suprarenal cortex.
carcinoma of suprarenal cortex.
Congenital adrenal hyperplasia and
Congenital adrenal hyperplasia and
Cushing syndrome
Cushing syndrome lead to precocious
lead to precocious
puberty in the male direction, i.e.
puberty in the male direction, i.e.
heterosexual precocious puberty;
heterosexual precocious puberty;
(b) Estrogen secreting adrenal tumor
(b) Estrogen secreting adrenal tumor
which is very rare.
which is very rare.

5. Ovarian causes
5. Ovarian causes :
:
(a)
(a) Estrogen producing tumors
Estrogen producing tumors as granulosa
as granulosa
and theca cell tumor;
and theca cell tumor;
(b)
(b) Androgen producing tumors
Androgen producing tumors as
as
androblastoma;
androblastoma;
(c)
(c) Choriocarcinoma
Choriocarcinoma because it secretes human
because it secretes human
chorionic gonadotrophin (HCG) which may
chorionic gonadotrophin (HCG) which may
stimulate the ovaries to secrete estrogen;
stimulate the ovaries to secrete estrogen;
(d)
(d) Dysgerminoma
Dysgerminoma if it secretes HCG.
if it secretes HCG.

6.
6. Juvenile hypothyroidism:
Juvenile hypothyroidism:
Lack of thyroxine leads to increased production of
Lack of thyroxine leads to increased production of
thyroid stimulating hormone and the secretion of
thyroid stimulating hormone and the secretion of
pituitary gonadotrophins may also be increased.
pituitary gonadotrophins may also be increased.
7.
7. Drugs:
Drugs:
 latrogenic may follow oral or local administration
latrogenic may follow oral or local administration
of estrogen.
of estrogen.
 A long course of estrogen cream used for treatment
A long course of estrogen cream used for treatment
of vulvovaginitis of children may lead to breast
of vulvovaginitis of children may lead to breast
development or withdrawal bleeding.
development or withdrawal bleeding.
8.
8. Silver syndrome:
Silver syndrome: Small stature, retarded bone age
Small stature, retarded bone age
and increased Gonadotrophin levels.
and increased Gonadotrophin levels.

1. History:
1. History:
It excludes iatrogenic source of
It excludes iatrogenic source of
estrogen or androgen.
estrogen or androgen.
It differentiates between
It differentiates between
isosexual and heterosexual
isosexual and heterosexual
precocious puberty.
precocious puberty.
Diagnosis of precocious puberty

2. Physical examination:
2. Physical examination:
It diagnoses McCune-Albright
It diagnoses McCune-Albright
syndrome.
syndrome.
Neurologic and ophthalmologic
Neurologic and ophthalmologic
examinations exclude organic
examinations exclude organic
lesions of the brain.
lesions of the brain.

3. Special investigations:
3. Special investigations:
These are done according to the
These are done according to the
history and clinical findings
history and clinical findings
and include:
and include:
FEMALE PRECOCIOUS PUBERTY
FEMALE PRECOCIOUS PUBERTY

a.
a. X-ray examination of the hand and wrist
X-ray examination of the hand and wrist
to determine bone age.
to determine bone age.
Estrogen stimulates growth of bone but
Estrogen stimulates growth of bone but
causes early fusion of the epiphysis.
causes early fusion of the epiphysis.
So the child is taller than her peers during
So the child is taller than her peers during
childhood, but she is short during adult
childhood, but she is short during adult
life.
life.
3
3
.
.
Special investigations
:
:

b.
b. Hormonal assay:
Hormonal assay:
including serum FSH, LH,
including serum FSH, LH,
prolactin, estradiol, testosterone,
prolactin, estradiol, testosterone,
17
17α
α-
-hydroxy progesterone, TSH,
, TSH,
and human chorionic
and human chorionic
gonadotrophin
gonadotrophin to diagnose
to diagnose
Choriocarcinoma.
Choriocarcinoma.
3
3
.
.
:
:

c
c.
. Ultrasonography
Ultrasonography
to diagnose ovarian or
to diagnose ovarian or
adrenal tumor.
adrenal tumor.
d.
d. CT or MRI
CT or MRI :
:
to diagnose an organic
to diagnose an organic
lesion of the brain, or adrenal
lesion of the brain, or adrenal
tumor.
tumor.
3
3
.
.
:
:

Hypothyroidism
Hypothyroidism
retards bone age,
retards bone age,
and is the only condition
and is the only condition
of precocious puberty in
of precocious puberty in
which bone age is
which bone age is
retarded
retarded

is diagnosed after
is diagnosed after
excluding all other
excluding all other
causes.
causes.
Idiopathic precocious
Idiopathic precocious
puberty
puberty
:
:

Treatment of precocious puberty
Objectives:
Objectives:
1.
1. Arrest maturation until normal
Arrest maturation until normal
pubertal age.
pubertal age.
2.
2. Attenuate & diminish established
Attenuate & diminish established
precocious characteristics.
precocious characteristics.
3.
3. Maximize adult height.
Maximize adult height.
4.
4. Avoid abuse, reduce emotional &
Avoid abuse, reduce emotional &
social problems
social problems

1.
1. Treatment of the cause
Treatment of the cause, e.g.,
, e.g.,
thyroxin for hypothyroidism,
thyroxin for hypothyroidism,
removal of ovarian and adrenal
removal of ovarian and adrenal
tumors.
tumors.
2.
2. Incomplete forms
of precocious
puberty do not require treatment,
puberty do not require treatment,
as estrogen production is not
as estrogen production is not
increased.
increased.

3
3
.
.
McCune-Albright syndrome
McCune-Albright syndrome
is treated with
is treated with testolactone
testolactone oral
oral
tablets.
tablets.
The drug inhibits the formation of
The drug inhibits the formation of
estrogen from its precursors, so
estrogen from its precursors, so
reduces estrogen level.
reduces estrogen level.
The dose is
The dose is 20 mg/kg
20 mg/kg body weight in
body weight in
4 divided doses
4 divided doses and increased to
and increased to 40
40
mg/kg
mg/kg body weight during a
body weight during a 3 week
3 week

4
4
.
.
Idiopathic type
Idiopathic type
is treated by explanation and reassurance and
is treated by explanation and reassurance and
by giving one of the following drugs which
by giving one of the following drugs which
inhibit the secretion of gonadotrophins:
inhibit the secretion of gonadotrophins:
(a)
(a)Gonadotrophin releasing hormone analogues
Gonadotrophin releasing hormone analogues
which are given as daily nasal spray, intramuscular,
which are given as daily nasal spray, intramuscular,
or subcutaneous injections every 4 weeks.
or subcutaneous injections every 4 weeks.
(b)Medroxyprogesterone acetate tablets
(b)Medroxyprogesterone acetate tablets (Provera
(Provera
tablets) or intramuscular injection (Depo-Provera);
tablets) or intramuscular injection (Depo-Provera);
(c) Danazol
(c) Danazol capsules;
capsules;
(d) Cyproterone acetate
(d) Cyproterone acetate tablets (Androcur).
tablets (Androcur).

Treatment is given till
Treatment is given till
the age of 12 years
the age of 12 years
(mean age of pubertal
(mean age of pubertal
development).
development).
4
4
.
.
Idiopathic type
Idiopathic type

Drug of choice because it achieves all objectives:
Drug of choice because it achieves all objectives:
1.
1. It acts by binding to the anterior pituitary receptors
It acts by binding to the anterior pituitary receptors
causing down-regulation & desensitization of the
causing down-regulation & desensitization of the
pituitary.
pituitary.
2.
2. Regression of symptoms occurs in the first year
Regression of symptoms occurs in the first year
3.
3. Delayed epiphyseal fusion; treatment more effective if
Delayed epiphyseal fusion; treatment more effective if
begun before bone age >12 yrs.
begun before bone age >12 yrs.
4.
4. Maintain E2 at <10 pg/mL.
Maintain E2 at <10 pg/mL.
5.
5. Children require higher doses than adults for
Children require higher doses than adults for
suppression.
suppression.
6.
6. Adrenarche will continue.
Adrenarche will continue.

McCune-Albright Syndrome
McCune-Albright Syndrome
:
:
 The disease is found more frequently in girls.
The disease is found more frequently in girls.
 It consists of a triad of :
It consists of a triad of :
1.
1. Precocious puberty,
Precocious puberty,
2.
2. Cystic changes in bones, and
Cystic changes in bones, and
3.
3. Cafe-au lait patches of the skin.
Cafe-au lait patches of the skin.
 The cause of precocious puberty is autonomous
The cause of precocious puberty is autonomous
production of estrogen by the ovaries.
production of estrogen by the ovaries.
 FSH and LH levels are low
FSH and LH levels are low.
.
 The treatment is
The treatment is testolactone
testolactone oral tablets which
oral tablets which
inhibit ovarian steroidogenesis.
inhibit ovarian steroidogenesis.

Delayed Puberty
Delayed Puberty
Secondary Sexual Characters
Secondary Sexual Characters
do not develop by the age of
do not develop by the age of 14 y
14 y
or
or
no menstruation till age of
no menstruation till age of 16y
16y

It is either :
It is either :
*
* Delayed onset:
Delayed onset: Breast bud does not
Breast bud does not
appear till 13 years or menarche does
appear till 13 years or menarche does
not occur till 16 years . or
not occur till 16 years . or
*
* Delayed progreession
Delayed progreession :
: Menarche
Menarche
does not occur within 5 years after
does not occur within 5 years after
breast bud .
breast bud .
Delayed Puberty
Delayed Puberty

Etiology of delayed puberty
1 -
1 - Constitutional
Constitutional
with +ve family history , short stature &
with +ve family history , short stature &
normal fertility .
normal fertility .
2 -
2 - Hypergonadotropic hypogonadism
Hypergonadotropic hypogonadism
(FSH > 40) = ovarian causes of Iry
(FSH > 40) = ovarian causes of Iry
amenorrhea = primary ovarian failure & 2ry
amenorrhea = primary ovarian failure & 2ry
ovarian failure (if occurs before puberty).
ovarian failure (if occurs before puberty).
3 -
3 - Hypogonadtropic hypogonadism
Hypogonadtropic hypogonadism =
=
hypothalamic & pituitary causes of Iry
hypothalamic & pituitary causes of Iry
amenorrhea e.g. Kallman's syndrome ,
amenorrhea e.g. Kallman's syndrome ,
Anorexia nervosa .
Anorexia nervosa .

4 -
4 - Normogonadtropic hypogonadism
Normogonadtropic hypogonadism
= end organ defects = uterine causes
= end organ defects = uterine causes
(Mullerian agenesis and testicular
(Mullerian agenesis and testicular
feminization syndrome), imperforate hymen
feminization syndrome), imperforate hymen
(c/o = delayed menarche + normal other
(c/o = delayed menarche + normal other
aspects of puberty), PCOD and Virilizing
aspects of puberty), PCOD and Virilizing
ovarian adrenal tumors .
ovarian adrenal tumors .
5 -
5 - General causes of amenorrhea
General causes of amenorrhea
(endocrinal or non-endocrinal especially
(endocrinal or non-endocrinal especially
malnutrition) if occurred before puberty
malnutrition) if occurred before puberty
&
&↓
↓GH & steroid synthesis defects .
GH & steroid synthesis defects .

Investigations of delayed puberty
History :
History :
1 - Family
1 - Family history
history , nutritional history , any
, nutritional history , any
systemic diseases
systemic diseases
(e.g. history of endocrinal disturbance).
(e.g. history of endocrinal disturbance).
2 -
2 - Clinical picture
Clinical picture of space occupying
of space occupying
lesion in the ovary , adrenal, pituitary &
lesion in the ovary , adrenal, pituitary &
hypothalamus.
hypothalamus.
3 - Periodic pain and +ve 2ry sexual
3 - Periodic pain and +ve 2ry sexual
characteristics in imperforate hymen .
characteristics in imperforate hymen .

Examination :
Examination :
(A)
(A) Body measurement
Body measurement for causes of
for causes of
amenorrhea +
amenorrhea + ↑
↑or
or ↓
↓weight, short or tall
weight, short or tall
stature , proportions (upper / lower segment
stature , proportions (upper / lower segment
ratio & arm span / height ratio).
ratio & arm span / height ratio).
(B)
(B) Tanner staging
Tanner staging of breast, pubic & axillary
of breast, pubic & axillary
hair if present.
hair if present.
(C)
(C) Clinical picture
Clinical picture of Turner , Mullerian
of Turner , Mullerian
agenesis & imperforate hymen .
agenesis & imperforate hymen .
(D)
(D) Neurological examination
Neurological examination for smell sense
for smell sense
(Kallman's syndrome), visual field & other
(Kallman's syndrome), visual field & other
cranial nerve lesions .
cranial nerve lesions .

Special Investigations
Special Investigations
:
:
1 -
1 - FSH & LH assay
FSH & LH assay important to
important to
differentiate level of the lesion &
differentiate level of the lesion &
progesterone assay in 17 OH
progesterone assay in 17 OH
deficiency .
deficiency .
2 -
2 - Chromosomal study
Chromosomal study if short stature
if short stature
or hypergonadotropic type .
or hypergonadotropic type .
3 -
3 - Radiological bone age
Radiological bone age study &
study &
radiologic study for pituitary adenoma
radiologic study for pituitary adenoma

Treatment of delayed puberty
Treatment of delayed puberty
*
* Constitutional :
Constitutional : Reassurance .
Reassurance .
* Treatment of the cause
* Treatment of the cause (if treatable) or
(if treatable) or
cyclic estrogen-progesterone hormone
cyclic estrogen-progesterone hormone
replacement therapy if the cause is not
replacement therapy if the cause is not
treatable , for 3 cycles: Norethistrone
treatable , for 3 cycles: Norethistrone
acetate 5 mg twice daily for 21 d or
acetate 5 mg twice daily for 21 d or
OCP
OCP
*
* Patient with
Patient with Y chromosome cell line
Y chromosome cell line :
:
Gonadectomy + hormone replacement
Gonadectomy + hormone replacement
therapy
therapy

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