REPRODUCCIÓN La idea fija
How male and female reproductive systems differentiate The reproductive organs and how they work How gametes are produced and fertilized Pregnancy, stages of development, birth & lactation Reproductive and developmental maturation and aging
Sex Determination: Overview Dimorphism: Males sperm Females eggs Chromosomes Autosomes Sex Chromosomes X - chromosome Y - chromosome Figure 26-1: Human chromosomes
Sex Determination: Overview Figure 26-2: Inheritance of X and Y chromosomes
Sexual Differentiation: Internal Embryonic Development Bipotential tissues: genes & hormones direct differentiation: Sex-determining Region Y Testis Determining Factor Gonad testis or ovary Wolffian duct Vas deferens, Mullerian duct oviduct
Sexual Differentiation: Internal Embryonic Development Figure 26-3a: Sexual development in the human embryo
Pathway for Sexual Development: Review for Genes to Organs Figure 26-4: Role of the SRY gene in male development
Sexual Differentiation: External Genitalia Bipotential tissues: genital tubercle, urethral folds, urethral groove and labioscrotal swellings
Sexual Differentiation: External Genitalia Figure 26-3b: Sexual development in the human embryo
Determination of sex Determined genetically by two sex chromosomes: XY or XX. Y is dominant and codifies the testis-determining gene product. Only one X is active. The other X condenses to form the Barr body.
Regulation of Reproduction: General Pathways Hypothalamus: pulse generator Gonadotropin releasing H (GnRH) Anterior Pituitary Lutenizing H (LH) Follicle stimulating H (FSH) Ovary: progesterone Estrogen, inhibin Testis: testosterone, inhibin
Regulation of Reproduction: General Pathways Figure 26-7: General pattern of hormonal control of reproduction
Hypothalamus-Pituitary-Gonadal Axis GnRH Hypothalamus GnRH Testosterone LH FSH Anterior Pituitary Oestrogen LH FSH Inhibin Inhibin Androgenic and anabolic effects Leydig Cells Sertoli Cells Testis Gonads Stimulatory Inhibitory Ovary Oestrogenic effects Theca interna Granulosa Androgens
Male Reproductive Components Testis => spermatozoa; testosterone production Epididymis => spermatozoa maturation & storage Ductus deferens & ampulla => transport & semen Accessory glands => semen a) Prostate gland b) Vesicular glands (seminal vesicles) c) Bulbourethral (Cowper s) gland Urethra => transport Penis=> transport and ejaculation
Male Reproductive Anatomy and Physiology Seminal vesicles Figure 26-9a: ANATOMY SUMMARY: Male Reproduction
Semen
Spermatogenesis: Sperm Production in the Testis Seminiferous tubules Spermatids Spermatocytes Spermatozoa Sertoli cells Interstitial tissue Leydig cells Capillaries
Spermatogenesis: Sperm Production in the Testis Figure 26-9b-e: ANATOMY SUMMARY: Male Reproduction
Cells of Leydig Produce Androgens Interstitial cells mainly (of Leydig) Testosterone
Seminiferous Tubule and Interstitial Cells
Regulation of Spermatogenesis Figure 26-11: Hormonal control of spermatogenesis
Regulation of Spermatogenesis GnRH LH Leydig cells testosterone 2 0 sex charact. GnRH FSH Sertoli cells spermatoctye maturation Inhibin feedback FSH, testosterone short & long loops
Female Reproductive Anatomy and Physiology: Overview Ovary Fallopian tube Fimbriae Uterus Cervix Endometrium Vagina Clitoris Labia
Female Reproductive Anatomy and Physiology: Overview Figure 26-12b: ANATOMY SUMMARY: Female Reproduction
Ovary: Details of Histology & Physiology Follicle Oocytes Thecal cells Granulosa cells Estrogen Corpus luteum Corpus luteum Progesterone Inhibin
Ovary: Details of Histology & Physiology Figure 26-12d: ANATOMY SUMMARY: Female Reproduction
Ovary: Details of Histology & Physiology Figure 26-12d: ANATOMY SUMMARY: Female Reproduction
Ovary: Details of Histology & Physiology Follicle Oocytes Thecal cells Androgens Granulosa cells Estrogens Corpus luteum Corpus luteum Progesterone Inhibin Folículos ováricos Región medular Región cortical
Ovary: Details of Histology & Physiology
Follicular Structure
Menstrual Cycle: Egg Maturation, and Endometrial Growth Follicular phase Egg matures Ovulation Egg released Luteal phase Corpus luteum Endometrium Prep for blastocyst No Pregnancy Menses Figure 26-13: The menstrual cycle
Figure 28.26 The Hormonal Regulation of the Female Reproductive Cycle Figure 28.26a-c
The Hormonal Regulation of Ovarian Activity ovulación Figure 28.25
Follicular Growth Regulation GnRH rises in response to a decline in inhibin and sex steroids GnRH stimulates rise in pituitary FSH & LH secretion. FSH stimulates new follicle growth LH induces thecal cell growth, vascularization & androgen synthesis FSH stimulates granulosa cell production of E2 & LH receptor
Follicular Growth Regulation 2 LH act on thecal & granulosa cells and FSH acts on granulosa cells Late follicular phase has elevated follicular fluid E2, P, FSH and LH but low androgens
Endocrine Control of Menstrual Cycle: Follicular Phase FSH stimulates follicular development Estrogen: + feedback, limits more follicles
Endocrine Control of Menstrual Cycle: Ovulation Estrogen LH "surge" & FSH spike egg release Inhibin pushes FSH down, new follicle development
Ovulation The stigmata, a coneshaped protrusion of the follicle wall, appears just before ovulation Preovulatory follicular fluid has elevated E2, P, FSH, LH, oxytocin, plasmin activity & collaginase activity Extensive follicular vascularization occurs immediately prior to ovulation
Endocrine Control of Menstrual Cycle: Follicular Phase and Ovulation Figure 26-14a,b: Hormonal control of the menstrual cycle
Endocrine Control of Menstrual Cycle: Luteal phase Granulosa cells form corpus luteum E2, progesterone progesterone & estrogen maintain endometrium Inhibin continues to limit new follicular development
Corpus Luteum Development 1 LH stimulates thecal & granulosa cell invasion of follicular cavity LH induces the luteinization of both cell types P synthesis increases as number of luteal cell increase
Corpus Luteum Development 2 LH stimulates increased P & E secretion FSH has no direct role in corpus luteum (CL) maintenance CL function depends on adequacy of follicle development (adequate induction by FSH of E2, LH and LDL receptor levels) Failure of adequate CL function results in luteal insufficiency
Corpus Luteum Development 3 Estrogen induces luteolysis Luteolysis causes decreased E2 & P secretion leading to decreased plasma levels Luteolysis continues in the absence of a fertilized ovum
Endocrine Control of Menstrual Cycle: Late Luteal phase Pregnancy: maintain progesterone, estrogen & inhibin No pregnancy: progesterone, estrogen & inhibin Menses, FSH & LH new follicle development
Endocrine Control of Menstrual Cycle: Luteal phase and Late Luteal phase Figure 26-14c, d: Hormonal control of the menstrual cycle
The Uterine Cycle Figure 28.20
Menstrual Cycle: Egg Maturation, and Endometrial Growth Follicular phase Egg matures Ovulation Egg released Luteal phase Corpus luteum Endometrium Prep for blastocyst No Pregnancy Menses Figure 26-13: The menstrual cycle
Overview of the Menstrual Cycle