Reproductive Systems Lecture PDF

The Reproductive  System Human Reproduction Humans are unisexual and exhibit sexual dimorphism Phases of Reproduction Gametogenesis – formation of gametes (spermatogenesis or oogenesis) Insemination – transfer of male gamete into the female re...

The Reproductive  System Human Reproduction Humans are unisexual and exhibit sexual dimorphism Phases of Reproduction Gametogenesis – formation of gametes (spermatogenesis or oogenesis) Insemination – transfer of male gamete into the female reproductive tract Fertilization – formation of diploid zygote Division / Cleavage – division of zygote; blastulation Implantation – fixing of the structure in the uterine tissue Placentation – connection formed (placenta) Gastrulation – formation of 3 germ layers (ectoderm, mesoderm,  endoderm) Organogenesis – formation of organs Parturition – expelling of fully-formed embryo/fetus from the female’s body Gestation period – (humans) from fertilization to parturition; 280 days or 9 months) MALE REPRODUCTIVE SYSTEM Organs of the Male Reproductive System Primary Sex Organ Testes – pair; male gonads Accessory Sex Glands Seminal vesicles Prostate gland Bulbourethral / Cowper’s gland Genital Ducts Epididymis Vas deferens / ductus deferens Ejaculatory duct  Urinogenital duct / urethra External Genitalia Penis Internal Structure of Testis Testis – gametes and hormones Tunica vaginalis – vaginal coelum containing hydrocoel Tunica albuginea – septa formation Testicular septum Seminiferous tubules – sperm formation Rete testes – networks Efferent ductules – connects to epididymis Path of Sperm Formation: seminiferous tubules straight tubule rete testes efferent ductules epididymis Internal Structure of Testis (cont.) Seminiferous tubules – site of sperm formation germ cells meiosis sperm cells Leydig cells (spermatogenesis) Germ cells Sertoli cells (nurse cells) – Sertoli cells Seminiferous nourishment Leydig cells – tubule secretes testosterone Epididymis Epididymis – storage site of sperms (18 – 24 hours) until physiological maturity is attained The Male RS Testis – extra-abdominal Epididymis – behind the testis Vas deferens – connects to the urethra Ampulla – opens the seminal vesicle Ejaculatory duct – seminal vesicles opens Urethra / Urogenital duct – carries urine and sperms Penis – copulatory structure Glans penis – slightly swollen tip Foreskin / prepuce – tip; loose skin fold Urinogenital opening – slit-like opening Prostate gland Bulbourethral glands – base of penis The Male RS (cont.) Glands: 1. Seminal vesicles secretes prostaglandins – activate sperms; cause contraction in the female reproductive tract 2. Prostate gland secretes bicarbonate ions, lipids, citric acid provides nutrition to sperms and pH regulation) 3. Bulbourethral gland secretes mucus – lubrication during copulation Semen = 90% gland secretions (seminal plasma) + 10% sperm cells The Male RS (cont.) Scrotal septum – separates 2 testis Inguinal canals – connection between the scrotum and abdominal cavity Gubernaculum – keeps testis in position Spermatic cord – helps in the passageway of sperm Dartos muscle – maintain temperature of scrotum Cremaster muscle – raise the testis and the scrotum upward for warmth and protection against injury Male External Genitalia Penis – external genitalia Erectile Tissues: 1. Corpora cavernosa – blood vessels 2. Corpus spongiosum – blood vessels and opening (urinogenital orifice)  FEMALE REPRODUCTIVE SYSTEM Organs of the Female Reproductive System Primary Sex Organ Ovaries – pair; female gonads Other Organs Uterus Fallopian tubes Vagina Glands The Female RS  Ovaries – in the pelvic region mesovarium – attaches ovary to the abdominal wall Fallopian tube Ampulla – site of fertilization Infundibulum – collects egg from ovary Fimbriae – creates suction to the egg Isthmus – tubular Uterus / womb – site of implantation Perimetrium – provides strength Myometrium – smooth muscles Endometrium – implantation Fundus – upper bulging part The Female RS (cont.)  Ovarian ligament – attaches ovary to the uterine wall Cervix – narrow tube which opens to the vagina Internal os External os Vagina – acts as birth canal and sperm receiver Vaginal orifice – opening Hymen – thin membranous structure Internal Structure of Ovary only 1 primary follicle will mature every 30 days Primary follicle Graafian follicle – secondary oocyte Ovulation – rupture Corpus hemorragicum – slight bleeding Corpus luteum (yellow body) – estrogen and progesterone (temporary endocrine gland) Corpus albicans (white body) Female External Genitalia Vulva – external genitalia Vestibule Urethral orifice – urine Vaginal orifice – penis receiver Hymen Labia minora – sebaceous glands Prepuce – covers the clitoris (erectile tissue) Labia majora – big folds; adipose tissues and sweat glands Bulbovestibular / Bartholin’s glands – secretes mucus Mons pubis – pubic hair Mammary Gland Mammary gland – milk Nipple Areola – dark circles Lactiferous duct – connects nipple to the lactiferous glands Ampulla – temporary stores milk Lactiferous glands – secretes milk HORMONAL CONTROL Hormonal Control of Male RS Hormones 1. Follicle Stimulating Hormone (FSH) – stimulates germinal epithelium Germ cells meiosis gametes Sertoli cells androgen-binding protein and Inhibin 2. Interstitial-cell Stimulating Hormone (ICSH) – stimulates Leydig cells Leydig cells androgens (testosterone) Androgen-binding protein + testosterone = high concentration is maintain Hormonal Control of Male RS Secondary Sex Characteristics puberty: 13 – 16 y/o spermatogenesis starts developed and functional secondary sex organs deep voice – enlargement of voice box body hair pattern increased height and broadened shoulders Hormonal Control of Female RS Hormones 1. Follicle Stimulating Hormone (FSH) – stimulates follicular cells Follicular cells estrogen and progesterone 2. Luteinizing Hormone (LH) – stimulates ovulation and maintains corpus luteum Hormonal Control of Female RS Secondary Sex Characteristics puberty: 11 – 16 y/o menstrual cycle starts ovulation starts widening of pelvic region enlargement of breasts and mammary glands deposition of fat in thigh and hips