ENDOCRINE REGULATION IN ADOLESCENT
Competencies-Based Curricullum4th Semester 7th Block
Definition
Growth is defined as an increase in size
Development is defined as a progression toward maturity
Thus the terms are used together to describe the complex physical, mental, and emotional processes associated with the “growing up” .
What do you understand by ADOLESCENCE ?
adolescence is derived from the Latin word “adolescere” meaning to grow, to mature
a period of human development encompassing the transition from childhood to adulthood.
What is puberty?
biological changes and sexual maturation that occur during the transition from childhood to adulthood.
Average age of onset: 10 (range 8-13) years in Girls12 (range 10-15) years in Boys
Endocrine Regulation in Puberty
Two processes contribute to physical manifestations of puberty: adrenarche & gonadarche
Adrenarche : - 6th - 8th years of age, adrenal androgen secretion- accompanied by :
a. Change in pilosebaceous b. Transient growth spurt and the c. Appearance of axillary & pubic hair but no sexual development Gonadarche : production of sex steroids for the development of
secondary sexual characteristics, permits the emergence of fertility, and mediates a wide range of other physiologic effects.
Hypothalamic-pituitary-gonadal axis
Female Puberty
OVARIAN REGULATION
HypothalamusHypothalamus
GnRH release
Pituitary glandPituitary gland
FSH LH
OvaryOvary
estrogenInhibin
FSH, LH and gonadal stimulation during female puberty
FSH increase in girls on puberty associate with ovarian activation
LH & FSH secretion occurs throughout day & night
FSH controlled mural granulosa cell to produce estradiol (most potent estrogen)
LH controlled theca cell to produce androstenedione
Estrogen
Estrogens produced by ovaries induce/maintain
secondary sexual characteristics and sustain germ
cell production
• Breast development
• Libido
• Body composition
• Bone mineralization
Growth Monitoring During Adolescent
8 Age (year) 14 14
Tanner’s staging of breast development in girls
Stage Breast Development (B) Anterior Lateral
1 Prepubertal; no breast tissue
2 Areolar enlargement with breast bud
3 Enlargement of breast & areola as single mound
4 Projection of arola above breast as double mound
5 Mature adult breast with single contour
Tanner’s staging of pubic hair development in girls
Stage Pubic Hair (PH) Picture
1 None None
2 A few darker hairs along labia
3 Curly pigmented hairs across pubes
4 Small adult configuration
5 Adult pubic hair configuration
Pubertal Growth Spurt • Pubertal growth accounts for about 20% of final adult height
• Pubertal total gain ~ 20-25cm in females and 30cm in males
• Growth spurt & Fat deposition : - 10-13 years girls taller & more
developed than same age boys
- Later stimulation of growth due
to increasing testosterone
0 2 4 6 8 10 12 14 16 18
Age (years)
24
22
20
18
16
14
12
10
8
6
4
2
Heig
ht
Gain
(c
m/y
ear)
Body Composition
The average lean body mass of teen females falls from 80%-74% to 16%-27% by the end of adolescence
Females experience a 120% increase in body fat during puberty
Teen females acquire approximately 1.14 kg of body fat mass each year during puberty.
Male Puberty
TESTICULAR REGULATION
HypothalamusHypothalamus
GnRH release
Pituitary glandPituitary gland
FSH LH
TestisTestis
TestosteroneInhibin(From the Leyding cells)(From the Sertoli cells)
FSH, LH and gonadal stimulation during male puberty v
LH acts primarily on leydig cell to stimulate testosteron synthesis
FSH acts on sertoli cell to reglate spermatogenesis
Growth Monitoring During Male Puberty
9 Age (years) 15
Tanner’s staging of puberty in boys
Stage
Genital Maturity Pubic Hair Gambar
1 Pre pubertal, testis 2ml
None
2 Enlargement testis > 4ml, reddening of the scrotum
A few darker hairs at the basis of the penis
3 Lengthening of the penis; Further enlargement of the testis to 6-10cm
Curly pigmented hair across pubes
4 Broadening of the glands penis; Growth of testis to 10-15ml
Small adult configuration
Secondary Sex Characteristic in Male Puberty
Testosterone –Deepens the voice and increases body muscle mass (lean body mass).
Change of body shape Body fat levels decrease among males
during adolescence, dropping to an average of 12% body fat by the end of puberty.
Thank
YouPuberty, 1894 Munch