3 Human Reproduction Male Reproductive Anatomy Spermatogenesis and Male HormonesMale Reproductive Technologies and Birth ControlFemale Reproductive AnatomyOogenesis and Female HormonesUterine and Ovarian CyclesDevelopment of the FetusParturition and LactationTeratogens and Birth DefectsReproductive Technologies
10 Male Reproductive System Scrotumholds the testes away from the body to keep them cool.Sperm production only occurs at temperatures about 3 degrees below body temperature.
11 Male Reproductive System Testisdescend about 2 months before birthspermatogenesisseminiferous tubule that produce sperm
12 Male Reproductive System Epididymis – holds sperm for about 2-4 days while they mature
13 Male Reproductive System Vas Deferensconducts sperm during ejaculationvasectomy: the vas deferens cut and tied off, to prevent conduction of sperm.
14 Male Reproductive System Ejaculatory Duct –propels semen and sperm through the urethra.Urethra –conduction of urine and semen out of the penis.a sphincter muscle closes off the bladder, preventing urine from exiting the urethra.
15 Male Reproductive System Penismale organ for copulation. Beneath the skin, lies the urethra surrounded by spongy protective tissue that expands to form the glans penis.Prepuce (foreskin) – is a loose sheath of skin covering the glans penis of uncircumcised males. The foreskin produces an oily secretion known as smegma.
16 Seminal Fluid Is produced by three different glands: Seminal Vesicles fluid high in fructose that provides energy sperm need to swimProstaglandins which cause contractions of muscles in the female reproductive tract to help move sperm in
17 Seminal Fluid Prostate Gland Cowper’s Gland milky white alkaline fluid that neutralizes the acidity of the vaginaCowper’s Glandbuffered fluid that cleanses and neutralizes the acidity in the urethra
18 SpermatogenesisSpermatozoa – are the smallest cells in the body. They have very little cytoplasm in the head, and a large tail (flagellum).
19 SpermatogenesisSpermatogonia – undifferentiated germ cells that have 46 chromosomesPrimary Spermatocytes – larger cells that undergo meiosis I
20 Secondary spermatocytes – cells that undergo meiosis II Spermatids – cells with 23 chromosomes, that are ready to mature in the epididymisSpermatozoa – mature sperm cells
23 TerminologyErectionparasympathetic nerve impulses dilate the arteries of the penis, allowing blood to flow rapidly into the highly vascular penile tissueveins are compressed preventing blood from leaving the penis.
24 TerminologyEjaculation – occurs when sexual stimulation forces semen to the urethra, where rhythmical muscle contractions cause the semen to be expelled from the penis.Infertility – the inability to produce viable sperm.Impotency – the inability to achieve a sustained erection.
26 Male Reproductive Hormones GnRH : gonadotropic releasing hormonereleased from hypothalamusstimulates the anterior pituitary to release LH and FSHLH : luteinizing hormonestimulates the interstitial cells (cells in between seminiferous tubules) of the testes to produce testosterone
27 Male Reproductive Hormones Testosterone – responsible for male secondary sex characteristics, required for sperm productionFSH: follicle stimulating hormonestimulates production of sperm in the seminiferous tubules
28 Male Reproductive Hormones Inhibinproduced by Sertoli cells when sperm count is highSends feedback to inhibit FSH and GnRH
32 Female External Structures (Vulva) Labia majora – large, fatty, hair covered folds that protect the genitalsLabia minora – smaller folds of skin inside the labia that are kept moist by secretionsClitoris – small shaft of erectile tissue
33 Female Internal Structures Vaginaintercourse : accepts the penisbirth canal during laborpH is generally acidic
34 Female Internal Structures CervixThick muscular tissueplugs closed with mucous during pregnancyprevents material from getting into the uterus, and holds the baby in
35 Female Internal Structures Uterus (womb)pear shaped muscular organ (5 cm wide)houses the developing fetus during pregnancy (30 cm wide)strong contractions help push the baby out during birth
36 Female Internal Structures Ovariesproduce the ovum from follicles found in the outer cortex
37 Female Internal Structures Oviducts /Fallopian tubesconduction of the ovum (egg) from the ovaries to the uteruswhere fertilization usually takes placeIf egg implants here = ectopic pregnancyfrequency
38 Female Internal Structures Fimbriaesmall fingerlike projections at the ends of the oviducts that sweep to draw the egg into the fallopian tube
40 Ovarian Structures Follicle cells that support and protect the ovum secrete estrogen to mature the ovumbecome a corpus luteum following ovulation.Ovum – egg cell, viable for about 24 hours after release.
41 Ovarian Structures Corpus Luteum cells remaining after a follicle has ruptured during ovulationsecretes progesterone and some estrogen for about 3 months if fertilization and pregnancy occursdeteriorates after about 14 days if fertilization does not occur.
43 Regulation of the Female Reproductive Hormones GnRH – stimulates the anterior pituitary to produce FSH and LHFSH – stimulates development of the follicle and the production of estrogen within the ovary
44 Regulation of the Female Reproductive Hormones LH – causes ovulation, development of the corpus luteum which secretes progesterone
45 Reproductive Hormones Estrogensecreted by the follicles in the ovariescauses maturation of the eggstimulates growth of the endometrium (uterus lining)Female secondary sex characteristicsInhibits FSH
46 Reproductive Hormones Progesteronesecreted by the corpus luteumcontinues preparation of endometriuminhibits both FSH and LH to prevent ovulationprevents uterine contractionsfirms the cervix
49 Day 1-5: Menstruation/Flow Phase Estrogen and progesterone levels are lowendometrium is sloughed off and shedDay 1-13: Follicular PhaseFSH secreted from ant. pit. promotes development of the folliclefollicle releases estrogen, which promotes growth of the endometrium.
50 Day 14: OvulationAn increase in LH causes the ovum to be releasedFSH is loweredDay 15 – 28: Luteal PhaseLH promotes formation of the corpus luteumcorpus luteum produces progesterone, inhibits GnRH, LH and FSH, preventing subsequent ovulation.
51 Many birth control pills are high in progesterone which prevents ovulation cancer
55 Fertilization Fertilization -union of sperm and secondary oocyte in the fallopian tubeOnly one spermatozoa will fertilize an eggNow called a zygotefertilization
56 Early Embryonic Development Zygote –fertilized egg, divides by cleavage, mitosis with no increase in size36 hours: 1st division (2 cells)60hours: 4 cells72h: 8 cellsMorula – solid ball of cells the same size as the fertilized egg (day4-5)
57 Early Embryonic Development Blastocysthollow ball of cells filled with fluid,outer layer forms the chorion, inner layer forms the embryoImplants day 7-10
59 Implantation embryo embeds itself in the endometrium. produces HCG (human chorionic gonadotropic hormone): maintains the corpus luteum for about 2-3 months.Reminder: corpus luteum produces progesterone and estrogen to maintain the endometrium and prevent ovulation)
60 hCG Pregnancy Test ELISA HCG detected in blood or urine with a pregnancy testhCG Pregnancy Test ELISA
61 Early Embryonic Development Gastrulathe blastocyst pushes in (invaginates) and forms the 3 primary germ layersthe hollow space forms a primitive gut2nd week
63 Germ Layers Ectoderm – nervous system and epidermis of the skin (hair, nails,retina, lens, inner ear, lining of the nose, mouth, anus and tooth enamel)Neurula- notochord/neural tube forms from the ectoderm layer (forms in 3rd to 4th week)
68 Extra Embryonic Membranes Amnion – inner membrane filled with fluid to provide protection, maintain temperature, swallowingChorion-outer membrane, contributes to placentaExtraembryonic coelom – fluid filled space between amnion and chorion
69 Extra Embryonic Membranes Allantois – collects nitrogenous wastes and forms the umbilical blood vesselsYolk Sac – surrounds embryo, first site of blood cell formation, becomes part of the primitive gut
70 Extra Embryonic Membranes Placentaforms around the fetusexchange of gases, delivery of nutrients and removal of wastes for the fetus
71 Extra Embryonic Membranes no blood shared between the mother and the fetusProduces progesterone and estrogen at about 4 months
78 Developmental Milestones 3 weeks – nervous system is evident, heart begins to form (2 tubes), heart beats around day 224-5 weeks – limb buds appear, eyes, ears and nose develop, umbilical cord is attached to placenta
79 Developmental Milestones 6-8 weeks – fetus is recognizable as a human, all organ system are developed, reflexes begin (size = 1.5”, 0.5 g)8th week = fetus
80 9-16 weeks – heartbeat is audible with a stethoscope, bone replaces cartilage, eyelashes formed, fetus can suck and swallow (size = 6”, 0.5 lb)
81 Developmental Milestones 17-28 weeks – movement is felt by mother, eyelids open (size = 12”, 3lb)Week 25: premature baby has 50% chance of survival
82 Developmental Milestones 32 weeks: fetus moves to head down position and lungs mature(good survival rate if born)
83 Developmental Milestones after about 32 weeks significant weight gain40 weeks: full term (size = 21”, 7.5 lbs)See summary chart on page 534
87 TeratogensTeratogens - chemical substances or infections that cause specific birth defects
88 Teratogens-Thalidomide-prescribed for morning sickness in the late 50’s and early 60’s-rubella during the first 12 weeks of pregnancy: eye problems, hearing problems and heart damage.
89 Parturition: Birth Hormones: -relaxin: made by placenta, loosens pelvis ligaments-prostaglandins – contractions-oxytocin from Post. Pit - contractions
90 ParturitionStage 1 – dilation and effacement(thinning) of the cervix, mucous plug dislodges, uterine contractions open the cervixStage 2 – delivery of the baby, cervix is dilated to about 10 cm, intense contractions every 1-2 min push the baby down the birth canalStage 3 – delivery of the placenta
91 ParturitionThe average labor lasts about 12 hours, but can range from 1 hour to 36 hours.caesarean section may be required.involves removing the baby from an incision in the front of the abdomen.
92 Lactationprolactin stimulates the glandular tissue in the breasts to produce fluids, colostrum, and milk.Colostrum is a rich fluid containing mostly sugar and proteins. This first milk is believed to play a role in early immunity.
93 LactationRegular suckling stimulates the pituitary gland to release oxytocincauses weak uterine contractions to return it to its pre pregnancy shapecauses “let down” of milk1.5 L of milk each day
94 Reproductive Technologies and Health Pap Smear – a sample of cervical cells are taken and examined for abnormal growth (cancer)Ultrasound – uses sound waves to view the baby in the wombUltrasound Scan Fetal Video Clips
95 Reproductive Technologies and Health Amniocentesis – sampling of the cells from the amniotic fluid at about 16 weeks to check for genetic abnormalitiesAmniocentesis Flash Animation
96 Reproductive Technologies and Health Chorionic Villus Sampling – sampling of cells from the chorion at about 5 weeks to check for genetic abnormalities
97 Fertility Technologies IVF – in vitro (in glass) fertilization – fertilizing the egg in a petri dish, and implanting the embryo 2-4 days laterLife Changine Science - Program 3: IVFAID – artificial insemination by donor, sperm is artificially placed in the vagina.
98 Fertility Technologies Egg Screening – testing and selecting eggs to be fertilized, fertility drugs produce eggs that are collected using a needle biopsyTSE – testicular sperm extractionremoval of sperm via biopsy (not ejaculation)ICSI – intracytoplasmic sperm injectionsperm head is injected directly into the egg
99 Fertility Technologies GIFT – gamete intra-fallopian transfersperm and egg are transferred to the fallopian tube for fertilizationAH – assisted hatchinga chemical solution is dripped over the egg to allow the sperm to penetrate more easily
100 Fertility Technologies Embryo Transfer – implantation of an embryo (at blastocyst stage) into the womb or fallopian tube, may be frozen or unfrozenFertility Drugs – induce ovulation, usually many ova are produced at one time, often results in multiples