PHYSIOLOGY OF SEXUAL MATING I NJOMAN WIDAJADNJA Why

PHYSIOLOGY OF SEXUAL MATING I NJOMAN WIDAJADNJA

Why Sex is Necessary .

Why is Sex Necessary? Mengapa sex diperlukan ? • Sexually dimorphic behaviors – Anatomical, physiological, and behavioral differences between males and females of the same species. • • Courting Mating Parental behavior Aggressive behavior Without these behaviors most species would not survive

Is Sexual Identity Learned? Apakah ciri 2 sex dipelajari? • The case of Bruce who became Brenda who became David – Socialization over biology? • XX (female) and XY (male) genes – A person’s genetic sex is determined by the father (genetik sex seseorang ditentukan oleh ayah) – SRY gene on short arm of Y chromosome- dictates the development of the fetal testis (testis-determining factor) and triggers action of receptors to receive chemical message hormone brings – SRY = regio penentu-seks dari kromosom Y

Is Sexual Identity Learned? • The Y chromosome controls the development of the glands that produce the male sex hormones (kromosom Y mengontrol perkembangan kelenjar yg memproduksi hormon kelamin pria) • The default sex (if the Y chromosome isn’t present or doesn’t work) is female (jika kromosom Y tdk ada atau tdk bekerja maka janin tsb wanita)

Initially, there are more males than females

• Perkembangan sex dimulai dari genom manusia • Setiap sel tubuh berinti (kecuali sel telur dan sperma) mengandung 46 kromosom • Pasangan kromosom ~ nomor diploid • 22 pasang autosom yg cocok (homolog) + 1 pasang kromosom sex • Sel telur n sperma : sel haploid (23 kromosom)

Sexual Development • Three categories of sex organs (primary sex characteristics) – Gonads (testes or ovaries) • Develop first (Sry testes; otherwise ovaries) • Produce ova/sperm and secret hormones • Critical Period of sexual development: Gestational weeks 7 -12 – Internal sex organs – External sex organs

Sexual Development Gonads can become either Testes or Ovaries Awalnya belum bisa dkenali: bipotensial. oleh pengaruh sinyal tepat gonad bag. korteks berkembang jadi ovarium dan medula jadi testis. Develop as a function of the presence or absence of SRY gene In males, at 7 th week, outer portions of gonads degenerate and inner portions develop into testes In females, at 11 th week, inner portions of gonads degenerate and outer portions develop into ovaries

Sexual Development Gonads become testes in males Testes - endocrine glands that produce • male hormones (androgens) • Mullerian Inhibiting Substance Most changes reflect the presence or absence of androgen

• Gen SRY menghasilkan protein TDF (faktor penentu testis) + DNA aktivasi SOX 9, WT 1 dan SF 1 • Perkembangan testis TIDAK membutuhkan testosteron ! • Segera setelah testis berdiff. mulailah disekresi 3 hormon : Sel Sertoli produksi AMH (anti mullerian hormon) sehingga duktus mulleri regresi.

• Sel Leydig produksi DHT (dihidrotestosteron) • Kedua hormon androgen ini adalah steroid H yg dominan pd Male. • Tetapi testosteron mengubah duktus Wolfii menjadi struktur asesorius laki 2: epididimis, vas deferens, vesikula seminalis • Dep. Fetus selanjutnya: testosteron mengatur migrasi testis masuk ke dlm kantong skrotum.

Sexual Development Gonads become ovaries in females Ovaries- endocrine glands that produce • female hormones (e. g. estrogen)

Sexual Development Internal sex organ precursors • Mullerian system female – Develops into fimbriae, fallopian tubes, uterus, and vagina (berkembang menjadi fimbria, tuba falopi, uterus, dan vagina) • Wolffian system male – Develops into epididymis, vas deferens, seminal vesiclesdi (berkemabang menjadi epididimis , vas deferens, vesikula seminalis) • Develop as a function of hormones released by testes – Mullerian inhibiting hormone or anti Mullerian hormone(defeminizing effect) – Androgens (masculinizing effect): testosterone/dihydrotestosterone

Sexual Development Wolffian Ducts - later become • epididymis • vas deferens • seminal vesicles Mullerian Ducts - later become • uterus • fallopian tubes • upper part of vagina

Sexual Development • External sex organs – Penis and scrotum in males – Labia, clitoris, and outer vagina in females – Female development is the default • “Nature’s impulse is to create a female” – Male development requires androgens

Undifferentiated External Genitalia (<7 weeks)

Partially differentiated external male & female genitalia

Fully developed male & female external genitalia

Fetal External Genitals: Female 11 -12 weeks 19 weeks

Fetal External Genitals: Female 5 months

Fetal External Genitals: Male 15 weeks 16 weeks

Sexual Development Dysfunctions • Androgen insensitivity syndrome ( sindrom kekurangpekaan androgen) – Genetic mutation that prevents the formation of androgen receptors (mutasi genetik dimana mencegah formasi reseptor androgen) • Gonads become testes (normal process) • Defeminization (normal process) • Lack of masculinization (abnormal process) An XY male with female external genitalia; have a woman’s body but not internal female sex organs

Sexual Development Dysfunctions disfungsi perkembangan sex • Persistent Mullerian duct syndrome – Failure to produce anti-Mullerian hormone (gagal memproduksi hormon anti muleri) – Absence of receptors for this hormone • In an XY male, defeminization does not occur but masculanization does • Person is born with both sets of internal sex organs • Turner’s syndrome – Individuals have only one sex hormone: an X chromosome (individu hanyamemiliki 1 kromosom X) • Essentially develop into females (normal internal/external sex organs) • However, no ovaries since two XX chromosomes needed

PUBERTY - development of secondary sex characteristic perkembangan karakteristik seks sekunder Puberty occurs when hypothalamus begins to secrete gonadotropin-releasing hormones (Gn. RH) causing pituitary to release (pubertas terjadi ketika hipotalamus mulai melepaskan Gn. RH yg menyebabkan hipofisis mengeluarkan hormon FSH dan LH) – Follicle-stimulating hormone (FSH) – Luteinizing hormone (LH) In males, these hormones stimulate testes to produce sperms and secrete testosterone (androgens) (pada pria FSH dan LH menstimulasi testis u/ produksi sperma dan testosteron In females, they stimulate the ovaries to produce estradiol (estrogens) (pada perempuan FSH &LH stimulasi oavarium produksi estradiol)

Puberty – cont. • Nutrition affects age of puberty (efek nutrisi terhadap usia pubertas) – Reduced in developing countries (menurun pd negara berkembang) – Thin girls reach puberty later (wanita kurus lebih lambat pubertas) • Due to the presence of leptin (seharusnya ada leptin)

Hormonal Changes in Puberty Hypothalamus FSHRF LHRF Anterior Pituitary

Hormonal Changes in Puberty Hypothalamus FSHRF LHRF Anterior Pituitary FSH LH OVARIES ICSH(LH) TESTES

Hormonal Changes in Puberty Hypothalamus FSHRF LHRF Anterior Pituitary FSH LH OVARIES Ovum Growth Ovulation Corpus Luteum Estrogen (estradiol) Progesterone ICSH*(LH) TESTES Testosterone Spermatogenesis * Interstitial-cell stimulating hormone

Sexual Maturation • Secondary sex characteristics (onset of puberty) – Females (estradiol) • • Enlarged breasts (pembesaran dada) Growth of the lining of the uterus (pertumbuhan lapisan uterus) Widened hips ( pelebaran pinggul) Maturation of genitalia (pematangan genitalia) – Females (androgens) • Underarm and pubic hair (face as well) androgen membuat pertumbuhan rambut axilla dan pubis ) – Males (androgens) • • • Facial, underarm, and pubic hair ( rambut wajah, axilla, dan rambut pubis) Deep voice (suara dalam) Alter hairline (baldness) ( Muscle development (perkembangan otot) Maturation of genitalia (pematangan genital) – Males (estradiol) • Enlarged breasts (pemebesaran dada)

Hormonal Control of Reproductive Cycle • Menstrual cycle – Begins with secretion of FSH to stimulate growth of ovarian follicles (epithelial cells surrounding each ovum) (mulai dgn sekresi FSH utk stimulasi pertumbuhan folikel ovarium ) – As ovarian follicles mature they secrete estradiol causing the growth of the lining of the uterus (preparation for fertilization) (setelah folikel ovarium matur , mereka memproduksi estradiol sehingga menyebabkan pertumbuhan lapisan uterus) – Increasing levels of estradiol triggers the release of LH causing ovulation (release of ovum) (peningkatan jumlah estradiol mencetuskan pelepasan LH menyebabkan ovulasi) – Ovum enters a Fallopian tube and starts migrating towards uterus. (ovum masuk ke tuba fallopi dan mulai berjalan ke uterus) – If it meets sperm and becomes fertilized it begins to divide and then attaches itself to uterus wall ( jika bertemu sperma dan terjadi fertilisasi mulai maka akan diteruskan ke dinding uterus) – If it is not fertilized, the ruptured ovarian follicle (corpus luteum) and the lining of the uterine wall will be expelled – menstruation commences (jika tdk terjadi fertilisasi , corpus luteum dan dinding uterus akan meluruh)

The Ovarian Cycle • Cycle averages 28 days (rata-rata siklus 28 hari) • Normal cycles last between 21 and 40 days (siklus normal alkhir antara 21 -40 hari) • Generally results in ovulation in only one ovary per month (umumnya hasil ovulasi hanya satu ovarium per bulan) • If two eggs are released: Fraternal twins (jika 2 telur dilepaskan : anak kembar) • Ovaries typically alternate

PSEUDOHERMAPHRODITISM • Pseudes = palsu. Hermaphrodites = keturunan hermes dan aphrodite yg berkelamin ganda • Laki 2 punya alat genital interna laki 2, namun ada defisiensi satu hormonnya. DHT yi 5αreduktase yg cacat. Meski sekresi testosteron normal, tapi tdk adekuat shg genitalia eksterna tdk berkembang sempurna pd fetus dan terlahir sebagai wanita. Dan bertumbuh n dibesarkan sebagai wanita.

• Pada saat pubertas : nampak perkembangan maskulinisasinya Tomboy • Berpengaruh pd perilaku sosial dan identitas sosial • Apakah lingkungan ikut berperan? Masih perlu penelitian lanjut!

Female Sexual Physiology: Reproductive Hormones Hormone Estrogen Where Produced Functions ovaries, adrenal glands placenta during pregnancy Promotes maturation of reproductive organs, development during puberty, regulates menstrual cycle, pregnancy Progesterone ovaries, adrenal glands Promotes breast development, maintains uterine lining, regulates menstrual cycle, sustains pregnancy Gonadotropinhypothalamus Releasing hormone (Gn. RH) Promotes maturation of gonads, Follicle-stimulating pituitary hormone (FSH) Regulates ovarian function and regulates menstrual cycle maturation of ovarian follicles HLED 403 Human Sexuality

Female Sexual Physiology: Reproductive Hormones Hormone Where Produced Functions Luteinizing hormone (LH) pituitary Assists in production of estrogen and progesterone, regulates maturation of ovarian follicles, triggers ovulation Human chorionic embryo and placenta gonadotropin (HCG) Helps sustain pregnancy Testosterone adrenal glands and ovaries Helps stimulate sexual interest Oxytocin hypothalamus stimulates uterine contractions in childbirth Prolactin pituitary stimulates milk production Prostaglandins all body cells mediate hormone response, stimulate muscle contractions HLED 403 Human Sexuality

Hormone Actions HLED 403 Human Sexuality

Fertilization (pembuahan) • The embryo produces Human chorionic gonadotropin (h. CG) • Maintains the Corpus Luteum and progesterone levels (menjaga corpus luteum dan tingkat progesteron) • Further enhances the secretory phase of the menstrual cycle HLED 403 Human Sexuality

Sexual response models • Masters and Johnson • Kaplan • Loulan HLED 403 Human Sexuality

Female Sexual Response Model • Masters and Johnson 4 Phase Model: – Excitement (gembira/hebat) – Plateau (stabil) – Orgasm (orgasme/puncak nafsu) – Resolution(ketetapan hati) HLED 403 Human Sexuality

Female Sexual Response Model • Kaplan’s Tri-Phasic Model – Desire (hasrat/keinginan) – Excitement (gembira/heboh) – Orgasm (orgasme) HLED 403 Human Sexuality

Female Sexual Response Model • Loulan’s Sexual Response Model: – Incorporates biological and affective dimensions • • • Willingness Desire (hasrat) Excitement (gembira) Engorgement ( Orgasm Pleasure HLED 403 Human Sexuality

Desire: Mind or Matter? • A complex interaction between – The neural system –sensory input – Hormones • Occurs throughout many parts of the body • Sexual Satisfaction Research HLED 403 Human Sexuality

Experiencing Sexual Arousal • Vasocongestion ( • Myotonia • Vaginal Sweating (vagina berair) • Tenting • Labia may enlarge or flatten and separate • Sex flush • Clitoris swells (clitoris membengkak) • Breathing and heart rate increase (laju napas dan jantung meningkat) • Nipples become erect, breasts may enlarge (puting tegak, pembesran payudara) • Uterus elevates (peninggian uterus) HLED 403 Human Sexuality

Orgasm • As excitement increases – Clitoris retracts beneath clitoral hood – Vaginal opening decreases by about 1/3 – Orgasmic platform • Continued stimulation brings orgasm: – Rhythmic contractions – Pleasure HLED 403 Human Sexuality

Stages of Sexual Response: Women and Men HLED 403 Human Sexuality