Diese Präsentation wurde erfolgreich gemeldet.
Wir verwenden Ihre LinkedIn Profilangaben und Informationen zu Ihren Aktivitäten, um Anzeigen zu personalisieren und Ihnen relevantere Inhalte anzuzeigen. Sie können Ihre Anzeigeneinstellungen jederzeit ändern.
Sexual
Differentiation
By
Vamsi Krishna Murthy Ginjupalli
UNIVERSITY OF SIENA
Sexual Differentiation
chromosomal sex
gonadal sex
hormonal sex
morphological sex
differences in physiology
Sexual Differentiation
chromosomal sex
gonadal sex
hormonal sex
morphological sex
differences in physiology
 each human cell contains 46 chromosomes, occurring in pairs
 23 pairs of chromosomes
 22 autosomes (determines e.g., h...
Sexual Differentiation
chromosomal sex
gonadal sex
hormonal sex
morphological sex
differences in physiology
Gonadal
Differentiation
Undifferentiated gonad develops as a
‘germinal ridge’ off of the
protokidney
The gonad at this sta...
Sexual Differentiation
chromosomal sex
gonadal sex
hormonal sex
morphological sex
differences in physiology
Ovaries: fairly quiescent during embryogenesis. They secrete very low levels of
estrogens, but don’t produce significant q...
Sexual Differentiation
chromosomal sex
gonadal sex
hormonal sex
morphological sex
differences in physiology
Sexual Differentiation
chromosomal sex
gonadal sex
hormonal sex
morphological sex
differences in physiology
Ductal system
...
Mullerian and Wolffian Duct Systems
cervix
The progenitors for the duct systems are present for both male and females
embryologically
In contrast to gonadal developm...
External
Genitalia
Development of male external genitalia is
dependent on dihydrotestosterone (DHT), an
androgen
-The skin...
Male:
 Testosterone secreted into the blood reaches the brain
 testosterone converted to estradiol and dihydrotestostero...
Brain Differentiation
testis
testosterone
TE
BRAIN
Tonic secretion of
GnRH in puberty
IN FEMALES?
Alpha-fetoprotein
Block...
Brain Sexual Chemistry
Summary
Undifferentiated
gonad
Y-chromosome:
SRYTDF
Embryonic
Testis
Sertoli cells
Leydig cells
MIH Mullerian duct
regres...
Sexual Differentiation
chromosomal sex
gonadal sex
hormonal sex
morphological sex
differences in physiology
Pathophysiology
• Male Anomalies
• Androgen insensitivity syndrome
• No functional androgen receptors
• 5-alpha reductase ...
thank you for your attention
vamsi
Nächste SlideShare
Wird geladen in …5
×

Sexual Differentiation (Learn easy way)

Learn sexual differentiation in very easy way.

  • Als Erste(r) kommentieren

Sexual Differentiation (Learn easy way)

  1. 1. Sexual Differentiation By Vamsi Krishna Murthy Ginjupalli UNIVERSITY OF SIENA
  2. 2. Sexual Differentiation chromosomal sex gonadal sex hormonal sex morphological sex differences in physiology
  3. 3. Sexual Differentiation chromosomal sex gonadal sex hormonal sex morphological sex differences in physiology
  4. 4.  each human cell contains 46 chromosomes, occurring in pairs  23 pairs of chromosomes  22 autosomes (determines e.g., hair color)  23rd pair are the sex chromosomes male: XY female: XX Chromosomal sex  Germ cells:  male: sperm - contains “X” or “Y”  female: ovum - contains an “X”  “Y” chromosome contains less genetic material than “X” chromosome
  5. 5. Sexual Differentiation chromosomal sex gonadal sex hormonal sex morphological sex differences in physiology
  6. 6. Gonadal Differentiation Undifferentiated gonad develops as a ‘germinal ridge’ off of the protokidney The gonad at this stage (pre 7-weeks) has a medullary and cortical region (inner and outer)(testes develop during the 7th week of gestation, ovaries develop during the 13th to 16th week) Without TDF input, the cortical region will develop into an ovary, and the medullary region will regress SRY causes development of the medullary region into a testis, and development proceeds from there, resulting from the hormones secreted by the gonads
  7. 7. Sexual Differentiation chromosomal sex gonadal sex hormonal sex morphological sex differences in physiology
  8. 8. Ovaries: fairly quiescent during embryogenesis. They secrete very low levels of estrogens, but don’t produce significant quantities of hormones until puberty to repeat: in the absence of hormones from a testis (differentiated because of SRY), morphological, neural, and behavioral development is female Testes: produce testosterone (from the leydig cells) and proteins (mullerian inhibiting hormone MIH from the sertoli cells) hormonal sex
  9. 9. Sexual Differentiation chromosomal sex gonadal sex hormonal sex morphological sex differences in physiology
  10. 10. Sexual Differentiation chromosomal sex gonadal sex hormonal sex morphological sex differences in physiology Ductal system External genitalia Differentiation of the brain
  11. 11. Mullerian and Wolffian Duct Systems cervix
  12. 12. The progenitors for the duct systems are present for both male and females embryologically In contrast to gonadal development, where one gonad becomes either male or female. mullerian vs wolffian 1) With no hormones, the mullerian duct develops, and the wolffian duct undergoes programmed cell death (regresses and degenerates) 1) This causes formation of female internal morphology 2) Mullerian system becomes fallopian tubes, uterus, and cervix 2) With testes present: 1) Leydig cells produce testosterone, cause development of wolffian ducts (turn off programmed cell death) 1) Wolffian ducts become vas deferens, seminal vessicles, and prostate gland 2) Sertoli cells produce Mullerian inhibitory hormone(MIH), cause regression of mullerian ducts 1) If the sertoli cells fail to produce MIH, a male can have both male and female internal structures Mullerian and Wolffian Duct Systems
  13. 13. External Genitalia Development of male external genitalia is dependent on dihydrotestosterone (DHT), an androgen -The skin of the genitalia contains the enzyme necessary to convert testosterone to DHT (5-alpha reductase) -The testis produces androgens, and in the genital area, that is converted to DHT, causing masculinization of the external genitalia (fusion of the genital swelling) Both males and females have this enzyme (5- alpha reductase) in the developing genitalia, but females have no T to convert at this time, so no DHT produced -If female is accidentally producing T, she can have masculinized genitalia at birth - If male does not produce the enzyme, external genitalia will be female.
  14. 14. Male:  Testosterone secreted into the blood reaches the brain  testosterone converted to estradiol and dihydrotestosterone in the brain  estradiol masculinizes the brain Female:  alpha-fetoprotein binds to estradiol  prevents estradiol from entering the brain  protects female brains from being masculinized by estradiol Brain Differentiation
  15. 15. Brain Differentiation testis testosterone TE BRAIN Tonic secretion of GnRH in puberty IN FEMALES? Alpha-fetoprotein Blocks estrogen in blood from entering brain
  16. 16. Brain Sexual Chemistry
  17. 17. Summary Undifferentiated gonad Y-chromosome: SRYTDF Embryonic Testis Sertoli cells Leydig cells MIH Mullerian duct regression testosterone Wollfian duct DHT Masculinization of external genitalia estrogen Masculinization of the brain
  18. 18. Sexual Differentiation chromosomal sex gonadal sex hormonal sex morphological sex differences in physiology
  19. 19. Pathophysiology • Male Anomalies • Androgen insensitivity syndrome • No functional androgen receptors • 5-alpha reductase deficiency • Cannot produce DHT • Female Anomalies • Masculinization • Exogenous treatment with androgenic steroids • Endogenous production of androgenic steroids (CAH) • Chromosomal Abnormalities • Turner Syndrome • Lack of (or damage to) second X chromosome • Kleinfelter Syndrome (XXY) • XYY
  20. 20. thank you for your attention vamsi

×