The ppt explains the Physiology of Puberty and Menopause. More of Physiology is available at https://www.youtube.com/channel/UC1QhJfPiWnmk2WpKVH1fzrQ

1. PHYSIOLOGY OF PUBERTY
AND MENOPAUSE
PY9.2: Describe and discuss puberty: onset, progression, stages;
early and delayed puberty and outline adolescent clinical
and psychological association.

2.  The student will be able to: (MUST KNOW)
 Define puberty and menopause.
 Understand the mechanism of onset of puberty in boys and girls.
 Name the Tanner’s stages of puberty and the features of pubertal development in each
stage.
 Appreciate the physiology of puberty.
 Comprehend the physiological basis of causation of precocious puberty and delayed
puberty.
 Understand the mechanism of onset of menopause and the features of menopause in
females.

3.  The period of transition from the non-reproductive state to the state of reproductive functions
that allows procreation is defined as puberty.
 During this period, the hypothalamopituitary-gonadal axis is activated to bring the gametogenic
functions of the gonads to their threshold of reproductive maturation.
AGE OF ONSET OF PUBERTY
In advanced nations, it occurs between the age of 8–13 in girls and 9–14 in boys. In
developing nations, the age of onset of puberty is 11–16 years in girls and 13–18 years in
boys.

4. In Boys
 The pubertal development in males occurs in five stages (by Tanner method, modified). Usually,
it is completed within two to four years from its onset.
 Stage I
 This is the preadolescent stage. There is no enlargement of external genitalia (penis, scrotum,
and testes). No pubic hair is present. However, secretion of adrenal androgen is increased
(adrenarche).
 Stage II
 Testes enlarge to more than 2.5 cm, which occurs due to growth of seminiferous tubules.

5. Stage III
Penis enlarges in length. Scrotum and testes are further enlarged. Pubic hairs become darker and
coarser above the pubis. Sperm first appears in the morning sample of urine (spermarche).
Stage IV
Penis enlarges in width and further in length. Scrotal and testicular enlargement continues. Pubic
hair becomes adult type. Ejaculation of sperm occurs either in dreams, or on masturbation or by
sexual act.
Stage V
Full adult pattern of sexual features develops.

6. Figs. (I to V): Stages of pubertal development in males.

7. HYPOTHALAMIC_PITUITARY_GONADAL AXIS

10. In Girls
The pubertal development in females is also described in five stages (by Tanner method,
modified). Usually, it is completed within two to five years from its onset.
Stage I
This is the preadolescent stage. There is no breast development. No pubic hair is present.
However, secretion of adrenal androgen is increased (adrenarche).
Stage II
Breast development starts (thelarche). Breast papilla is elevated and the diameter of areola is
increased. Secretion of estrogen from the ovary increases significantly. Sparse hairs appear along
the labia majora

11. Stage III
Breast enlarges with the enlargement of areola. Pubic hairs develop, grow, and become dark
(pubarche). Hairs appear in axilla.
Stage IV
Breast further enlarges with areola and papillae projecting out of it. Pubic hair becomes adult type,
but covers a smaller area. Menstrual cycle starts (menarche), but irregular at the beginning.
Stage V
Full adult pattern of breasts and pubic hairs develop. Menstrual cycle occurs regularly.

12. Figs. 122.2 (I to V): Stages of
pubertal development in females.
1. Adrenarche
2. Thelarche
3. Puberache
4. Menarche

13.  Fig: Changes in plasma
hormone concentration
during Puberty in Girls.

14. The development of secondary sexual characteristics without gametogenesis is called as
precocious pseudopuberty. This occurs due to exposure of immature males to abnormal quantity
of androgen, and in immature females the abnormal exposure to estrogen.
 Precocious pseudopuberty occurs due to following causes:
 Adrenal causes: Congenital virilizing adrenal hyperplasia can lead to precocious
pseudopuberty. Androgen secreting or estrogen secreting tumors of adrenal gland resulting in
precocious pseudopuberty are not uncommon.
 Gonadal causes: Leydig cell tumor of testis in male or granulosa cell tumor of ovary in
females can cau.se precocious pseudopuberty.

16.  When onset of puberty is delayed beyond the age of 17 in girls and 20 in boys, the
condition is called delayed puberty.
 It occurs usually due to panhypopituitarism that causes failure of maturation of
gonads.
 It is also associated with chromosomal abnormality of XO pattern or gonadal
dysgenesis.
 Puberty may be delayed in spite of presence of normal gonads, which is called
eunuchoidism in males and primary amenorrhea in girls.

17. With advancement of age, gonadal functions gradually decrease. In females, ovaries become
unresponsive to the gonadotropins. The functions of gonads slowly decrease finally resulting in
complete cessation of menstrual cycle. This is called menopause or climacteric.
 Mechanism of Menopause
The mechanism and purpose of menopause are not clear. The female gonads progressively
become unresponsive to gonadotropins with advancing age. The mechanism by which ovarian
responsiveness decreases is not known. Ovaries stop secreting progesterone and estrogen in an
appreciable amount. The negative feedback effect of ovarian hormones causes increased
secretion of LH and FSH. The uterus and vagina become atrophic.

18. 1. In women, onset of menopause occurs between the age of 45 and 55 years. In
recent years, the age at menopause has gradually increased.
2. In males, though there is some decline in reproductive capacity from 5th decade of
life, climacteric does not occur. Testicular functions and potency persist till 8th
decade. Thus, in males, there is no andropause (male menopause).

19.  Hot flushes (sensation of warmth spreading from trunk to the face) occur frequently. Night
sweating, tachycardia, and mental symptoms are also observed.
1. The mechanism of hot flushes is not exactly known but it coincides with the surges of
LH secretion.
2. With the onset of menopause, LH secretion is increased, which occurs in episodes of
30–60 minutes. This is called circhoral secretion of LH.
3. Each hot flush coincides with an episode of LH surge. However, experimental evidences
indicate that hot flushes are not due to episodic secretion of LH per se.
4. The decreased secretion of estrogen triggering some hypothalamic mechanism is
proposed to cause both episodic secretion of LH and hot flushes.

25.  The fear that the women will lose her womanhood may cause psychological
depression.
 It needs proper care, counseling, and assurance of the spouse to make her
understand and adjust to this physiological phenomenon of the nature.
 In some cases, hot flushes and psychological symptoms become more problematic.
In such women, hormonal supplementation of estrogen is usually helpful.
 However, metabolic and other complications of estrogen should be kept in mind
while continuing estrogen therapy for a longer period.