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