Puberty & Menarche by 791FJz1y

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									                      Puberty & Menarche
                       Dr. Mohamed Sultan, 2009



Definition
Puberty... Sequence of events occurs in the physical change resulting in
the adult fertile female; it marks the change from childhood to
adolescence.
The age is variable, but it is abnormal if there is no sign of 2ry sexual
development at the age of 14.



Puberty changes
1. Growth acceleration (spurt)... GH
2. Breast development (Telarche ).. Estrogen
3. Pubic hair ( Adrenarche ).. Androgens
4. Menstruation (Menarche)
5. Axillary hair
- This is the sequence of events in 70% of cases , variation often occurs.



Pathophysiology

- Gonadarche theory  Hypothalamus released from inhibition ( ?
Pineal atrophy , ? CNS inhibitory factors)

The trigger for changes to start is an increasing frequency & amplitude
of pulses of Gonadotrophins release , the ovaries are then stimulated
to begin to produce estrogen which acts on the breast tissue to promote
growth.




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Pubic hair growth is stimulated by androgens released by the ovaries
& the adrenals.

Estrogen promotes epiphysis closure , so final height is usually attained
about tow years after menarche.

1. Growth spurt
• Begins around age of 11 yr.
• The rate increases 6-10 cm / yr. for 2 yr.
• Finally the effect of estrogen causes fusion of the end plate of long
bones & growth ceases , so by age 15 , most girls have achieved their
final stature .

                                       LHRH

                                         

                                     FSH, LH


                                         

                                  .... Ovaries…. 

                        Androgens               Estrogen

                                                      
                  Pubic hair                      Breast tissue
                  Axillary hair                  Endometrium
                                                  Bone epiphysis



                   Fig. ( 1 ) puberty Pathophysiology




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2. Breast development ( Telarche)
Breast bud respond to the production of estradiol by the ovary.



                           Tanner Classification


 Stage                     Breast development
  I              Prepubertal ( no breast tissue )


  II                  Breast bud


  III             Enlargement of breast & areola


  IV          Projection of the areola & nipple to form 2ry mound

               Mature , adult configuration , smooth contour
  V




3. Adrenarche

* The maturational in the adrenal production of androgens e.g.
Testosterone , Androstenedion , Dehydroepianrosterone (DHEA) &
DHEAS.

*It accounts for the normal development of axillary & pubic hair


4. Menarche
       Menarche.. The 1st menstruation .
       Age variable ..9 – 17 yr .



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Fig. ( 2 ) Tanner Classification for Breast development




  Fig. ( 3 ) Tanner Classification for Pubic hair development




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       Tanner Classification for Pubic hair development
    Stage Pubic hair
        I      Prepubertal, no pubic hair

       II      Sparse growth along the labia

       III     Hair coarser, darker, & more curried over mons

       IV      Adult type hair, but no spread to thighs

       V       Adult , with horizontal upper border & spread to thighs




    The axis not fully mature … subsequent cycles are commonly
       irregular ( Anovulatory cycles ) , so It may takes 5-8 yr for girls to
       develop ovulatory cycles 100% of the time .
   
       Bleeding may be excessive & prolonged , this may leads to :

             - Missing school

             - Anemia

             - Blood transfusion

    Exclude a coagulation disorder .



Precocious Puberty
Menarche before age of 9 yr.
a. True PP
Development of secondary sexual characteristics & Ovaries (premature
development of Hypothalamic Pituitary Ovarian axis)
Causes
1. Constitutional in 80-90%



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2. Brain lesions e.g. Cerebral tumors, meningitis.



b. Pseudo PP
Development of secondary sexual characteristics but not the ovaries
Causes
1. Virilizing tumors of the adrenal or feminizing tumors of the ovary
2. McCune Albright syndrome (PP, Cafe’au lait , bone fibrous dysplasia).
3. Iatrogenic (COPs)



c. Partial PP e.g. premature Telarche, Adrenarche.



Delayed Puberty
- Girls with no signs of puberty by age of 14 yr, or require > 4yr to
complete the pubertal process.
Causes (see the lecture of 1ry amenorrhea)
1 .Constitutional ( >90%)
2.Hypogonadotrophic hypogonadism
* Chronic illness   *Anorexia nervosa * Athletic
* Kallman’ s syndrome       * Trauma
3 .Hypergonadotrophic hypogonadism
* Turner’s syndrome     * Ovarian damage
* Galactosemia      * Autoimmune ovarian failure
* l7alpha hydroxylase deficiency




                                                M.Sultan/2010




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