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Growth_and_puberty

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					Growth and puberty
Objective
   What do we mean by growth percentile
    chart? what is the growth velocity?
   To know the growth pattern in deferent age
    group
   What are the endocrine control of growth?
   What is the Stages of puberty?
   What factors affecting growth? Causes of
    delay
   What is constitutional growth delay?
Growth chart
Growth velocity
 Growth in children

Human linear growth can be divided into three phases


       Growth in infancy

       Growth in childhood

       Growth during puberty
     Growth in infancy

   linear growth is initially rapid
       Approximately 25 cm/12 m.

       2nd year 12 cm



   The major regulating influence of
    growth is nutritional status
    Growth in childhood

   Nutrition becomes less important
   Hormonal influences
       Growth hormone (GH)
       Insulin-like growth factor (IGF) axis,
       Thyroid status is also a requisite for
        normal growth.
   Height velocity ranges between 4
    and 8 cm/year
    Growth during puberty

   Growth changes dramatically,
   Adolescent growth spurt (AGS)
      caused by↑ androgen and
       estrogen, Which result in ↑↑
       GH secretion
   Growth during puberty

In females
 The onset of the AGS coincides
   with the start of clinical puberty
   SMR1
 Peak height velocity occurs at
   about 12 years
 Menarche occurs when height
   velocity is falling and is followed
   by approximately 2 years (5 cm)
 Greater amplitude of the AGS in
   males about 8 cm
  Growth during puberty

In males
 The AGS begins when puberty is
   already well established
   (testicular volume of 10-12 ml)
 Reached at an average age of
   approximately 14 years
 Greater amplitude of the AGS in
   males about 10 cm
Endocrine control of growth
   Growth hormone (GH) is the
    major endocrine regulator of
    linear growth
   The insulin-like growth
    factors (IGF-I, IGF-II)
    mediate many of the
    biological actions of GH
   The IGFBPs extend the half-
    life of the IGF peptides,
    transport them to target
    cellIGF-I binds to
   the Type 1 IGF receptor in
    target tissues such as the
    growth plate at the ends of
    long bones
     Puberty

   A time of physiological development between childhood
    and adult life
   Secondary sexual development occurs as a result of
    activation of the hypothalamic-pituitary gonadal axis
Pubertal stages (Female)

             Tanner stages of female breast and pubic
             hair development
Pubertal stages (Male)
                  Tanner stages of male genitalia development
Causes of delayed growth

 Genetic: Familial, constitutional (CDP)
 Endocrinal GH, thyroid, hypogonadism, cushing
    syndrome. IDD
   Bone and cartilage disorders (Achondroplasia)
   Chromosomal and syndrome:Turner, Down
    syndrome,
   Nutritional , Psychological: Child abuse,
    depravation , nutritional deficiency
   Inborn error of metabolism (Galactosemia,
    Glycogen storage disease.
   Chronic illnesses, CHD, CF, GI, renal ,CNS
Turner syndrome
GH deficiency
Hypothyroidism
COELIAC DISEASE
Achondroplasia
Skeletal dysplasia
GLYCOGEN
STORAGE
DISEASE
Constitutional Growth Delay

 Delayed Growth in Normal Children
 Growth in the first 2-3 years is normal
 More common in boys than in girls
 Cross line Are small for their age (growth is at or
  below the 5th percentile line on the growth chart)
 Have a delayed bone age (usually 1 to 4 years behind
  their chronological age)
 They continue to grow at the slow, steady rate of
  childhood for longer than most of their friends.
Constitutional Growth Delay

 Have no signs or symptoms of diseases or conditions
  that affect growth
 When they finally enter puberty at about age 15 for
  boys and 14 for girls, they have a normal growth
  spurt and normal sexual development
 Their adult height usually is similar to that of their
  parents
 Sometimes runs in families

				
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posted:8/26/2012
language:English
pages:26