Pregnancy Mark Ewoldsen, Ph.D. AP Environmental Science 1 Works Cited 1. Animal Development PowerPoint by Nancy G. Morris, Volunteer State Community College @ www2.volstate.edu/msd/bio/1120/Powerpoint/Animal%20Development.ppt 2. R. Brown CO State @ http://www.vivo.colostate.edu/hbooks/pathphys/reprod/fert/fert.html 3. Web MD @ http://www.webmd.com/baby/slideshow-fetal-development 4. Baby Center @ http://www.babycenter.com/fetal-development-imagesgallery.htm#1241732358427_1 5. Wilcox et al. New Eng J Med 333:1517, 1995 6. The First Three Weeks, Thomas A. Marino, Ph.D., Department of Anatomy and Cell Biology, Temple University School of Medicine @ isc.temple.edu/marino/2005/Early/First_Three_Weeks.ppt Fertility •Conception probability • Study in healthy women • group of 221 women were in the trial • data were collected from a total of 625 menstrual cycles • 192 pregnancies were established • 129 resulted in delivery of a baby. 11 21 day Cycle 28 day Cycle 35 day Cycle Monday Tuesday Wednesday Thursday Friday Saturday Sunday 18 Cycle Begins 19 little Fertile 20 Fertile 21 little Fertile 22 VERY Fertile 23 VERY Fertile 24 VERY Fertile 25 Ovulate 26 27 28 29 30 31 7 1 2 3 4 5 6 Cycle Ends 8 9 little Fertile 11 little Fertile 12 VERY Fertile 13 VERY Fertile 10 Fertile 14 VERY Fertile 15 Ovulate 16 17 18 19 20 21 22 23 24 1 21 day Cycle 28 day Cycle 35 day Cycle Monday Tuesday Wednesday Thursday Friday Saturday Sunday 18 Cycle Begins 19 20 21 22 23 24 25 26 little Fertile 27 Fertile 28 little Fertile 29 VERY Fertile 30 VERY Fertile 31 VERY Fertile 1 Ovulate 2 3 4 5 6 7 8 9 10 11 12 13 14 Cycle Ends 19 little Fertile 20 Fertile 21 little Fertile 15 16 17 18 22 VERY Fertile 23 VERY Fertile 24 VERY Fertile 1 Ovulate 21 day Cycle 28 day Cycle 35 day Cycle Monday Tuesday Wednesday Thursday Friday Saturday Sunday 18 Cycle Begins 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 little Fertile 3 Fertile 4 little Fertile 5 VERY Fertile 6 VERY Fertile 7 VERY Fertile 8 Ovulate 9 10 11 12 13 14 21 15 16 17 18 19 20 Cycle Ends 22 23 24 1 21 day Cycle 28 day Cycle 35 day Cycle Monday Tuesday Wednesday Thursday Friday Saturday Sunday 18 Cycle Begins 19 little Fertile 20 Fertile 21 little Fertile 22 VERY Fertile 23 VERY Fertile 24 VERY Fertile 25 Ovulate 26 little Fertile 28 little Fertile 29 VERY Fertile 30 VERY Fertile 31 VERY Fertile 1 Ovulate 2 little Fertile 3 Fertile 4 little Fertile 5 VERY Fertile 6 VERY Fertile 7 VERY Fertile Cycle Ends 8 Ovulate 9 little Fertile 10 Fertile 11 little Fertile 12 VERY Fertile 13 VERY Fertile 14 VERY Fertile Cycle Ends 19 little Fertile 20 Fertile 21 little Fertile Cycle Ends 27 Fertile 15 Ovulate 16 17 18 22 VERY Fertile 23 VERY Fertile 24 VERY Fertile 1 Ovulate Human Sexual Response •Masters and Johnson (1957 1990s) • Physiological responses determined pioneered research into the nature of human sexual response • Diagnosis and treatment of sexual disorders and dysfunctions Sexual Response Model •Excitement (arousal) • Erotic physical or mental stimulation, • kissing, petting, or viewing erotic images • Body prepares for coitus, or sexual intercourse, in the plateau phase • increase in heart rate (tachycardia) • increase in breathing rate • rise in blood pressure • nipple erection - nearly all females and ~60% of males • sex flush - ~50-75% of females and 25% of males • erectile tissue starting to fill Sexual Response Model •Plateau - period prior to orgasm • Both Sexes • • increases in circulation and heart rate • • muscle tension increases • may begin to vocalize involuntarily sexual pleasure increases with increased stimulation respiration continues at an elevated level Sexual Response Model •Plateau - period prior to orgasm • Male • urinary bladder closes • prevent urine from mixing with semen • guard against retrograde ejaculation • muscles at the base of the penis begin a steady rhythmic contraction • may secrete seminal fluid or preejaculatory fluid Sexual Response Model •Plateau - period prior to orgasm • Female • • • • • • areola and labia further increase in size clitoris withdraws slightly Bartholin glands produce further lubrication tissues of the outer third of the vagina swell considerably pubococcygeus muscle tightens • reducing the diameter of the opening of the vagina • creating what Masters and Johnson refer to as the orgasmic platform for those who never achieve orgasm, this is the peak of sexual excitement Sexual Response Model •Orgasm - conclusion of the plateau phase • Both males and females • quick cycles of muscle contraction in the lower pelvic muscles • surround both the anus and the primary sexual organs • other involuntary actions • • • • vocalizations muscular spasms in other areas of the body generally euphoric sensation heart rate is increased even further Sexual Response Model •Orgasm - conclusion of the plateau phase • Males • • usually associated with ejaculation each spurt - wave of sexual pleasure • • • other sensations felt strongly - lower spine, or lower back first and second convulsions • • especially in the penis and loins most intense in sensation/greatest quantity of semen each contraction thereafter • diminishing volume of semen/milder wave of pleasure Sexual Response Model •Orgasm - conclusion of the plateau phase • Females • experience uterine and vaginal contractions • may also play a significant role in fertilization • muscular spasms aid in the locomotion of sperm up the vaginal walls into the uterus Sexual Response Model •Resolution phase - after orgasm • Male and Female • • • • allows the muscles to relax blood pressure to drop body to slow down from its excited state may or may not experience a refractory period • further stimulation may cause a return to the plateau stage • allows the possibility of multiple orgasms in both Sexual Response Model •Resolution phase - after orgasm • Males typically enter this refractory period (and fall asleep) • may find continued stimulation to be painful • Females do not have a similar refractory period • can repeat cycle almost immediately. • Refractory periods range from human to human • immediate (no refractory) • as long as 12 to 24 hours Duration of Intercourse •Ends • often when man has ejaculated (and falls asleep) • woman might not have time to have an orgasm • many men suffer from premature ejaculation • many women require a substantially longer duration of stimulation •Foreplay • on average women and men took almost the same time for sexual arousal • around 10 minutes • time needed is very individualistic • varies from one time to the next Duration of Intercourse •Kinsey study • under half of men reported five minutes or less • about a fifth claimed 10 minutes or longer • others may have taken over one hour. •Canadian & American sex therapists • average time was 7 minutes • 1 to 2 minutes was too short • 3 to 7 minutes was adequate • 7 to 13 minutes desirable • 10 to 30 minutes was too long 17 The Voyage •Freshly ejaculated sperm are unable or poorly able to fertilize •Capacitation • physical changes to surface and cytoplasm • location 16 Credit: © Dr. David Phillips/Visuals Unlimited Human Sperm entering the oviduct. SEM X500. 350626 Zonae Pellucidae •Thick extracellular coat that surrounds all mammalian eggs and preimplantation embryos • three glycoproteins • ZP3 allows species-specific sperm binding • ZP2 mediates subsequent sperm binding • ZP1 cross-links ZP2 and ZP3 5 Binding to Egg • Binding of sperm to the zona pellucida • receptor-ligand interaction • species specificity • Zona glycoproteins are sperm receptors 25 Fertilization - Week Two • One sperm beats out all the others and reaches the egg - conception • Genetic make-up is complete • Within three days • divides rapidly into many cells • passes through the fallopian tube into uterus • attaches to the uterine wall • placenta (nourish the baby) begins to form 35 Fertilization - Week Two • One sperm beats out all the others and reaches the egg - conception • Genetic make-up is complete • Within three days • divides rapidly into many cells • passes through the fallopian tube into uterus • attaches to the uterine wall • placenta (nourish the baby) begins to form 35 Morula Differentiation 43 Week 1 • The blastocyst consists of : Inner Cell Mass (embryoblast) Trophoblast Blastocele Uterine Artery Uterine Gland Epithelium of Uterus Inner Cell Mass Trophoblast Blastsocele Week 1 Week 2 Day 7.5 Inner Cell Mass Cytotrophoblast Blastocyst Cavity Syncytiotrophoblast Four Weeks nd (2 ) •A home pregnancy test is now positive •Ten thousand times larger than the fertilized egg •Structures that eventually form the face and neck are becoming evident •Heart and blood vessels continue to develop •Lungs, stomach, and liver start to develop 51 QuickTime™ and a Video decompres sor are needed to see this picture. 49 Gastrulation & Neurulation 57 Hox Box 55 Five Weeks • Brain is beginning to grow • Eyes, legs, and hands begin to develop 63 Credit: © Mediscan/Visuals Unlimited Human 33-day embryo measuring 7 x 3.2mm. 3597 59 Six Weeks •Heart is beating •Brain waves are detectable •Mouth and lips are present •Fingernails are forming 68 Credit: © Carolina Biological/Visuals Unlimited Human embryo at 40 days. 214007 Credit: © Carolina Biological Human embryo at 40 days. 213989 Credit: © Carolina Biological/Visuals Unlimited . Human embryo at 40 days 214006 Seven Weeks • Baby has slightly webbed fingers and toes • Eyelids, and toes form, nose distinct • Baby is kicking and swimming 72 • 5 weeks after conception 65 Credit: © Mediscan/Visuals Unlimited Human fetus in utero at 7-weeks 3595 Eight Weeks • Bend his elbows and knees • About the size of a grape – almost an inch in size • Eyelids and ears are forming • Tip of the nose is visible • Arms and legs are well formed • Fingers and toes grow longer and more distinct • Baby is kicking and swimming 76 Nine Weeks • Eyelids now cover eyes 82 73 75 Ten Weeks • Hands now meet over heart • Teeth begin to form, fingernails develop • Baby can turn his head, and frown • Baby can hiccup. 85 Credit: © Mediscan/Visuals Unlimited Human fetus in utero at 10-weeks. 3594 Eleven Weeks • Baby is busy kicking and stretching • baby can “breathe” amniotic fluid and urinate • Baby can grasp objects placed in its hand • All organ systems are functioning • Baby has a skeletal structure, nerves, and circulation 88 Twelve Weeks • Measures about two and a half inches • Synapses are forming in brain • Starts to make its own movements. • Baby's heartbeat heard with special instruments • Sex organs of the baby start to become clear • Baby has all of the parts necessary to experience pain, including nerves, spinal cord, and thalamus • Vocal cords are complete • Baby can suck its thumb. 90 Thirteen Weeks • Fingerprints are new this week, and they're one of a kind. 93 Fourteen Weeks • Baby can grimace and squint • At this age, the heart pumps several quarts of blood through the body every day. 95 Fifteen Weeks • Boy or girl? It's now possible to tell • Baby has an adult’s taste buds 97 Sixteen Weeks •Fetus now measures about 4.3 to 4.6 inches and weighs about 2.8 ounces •Baby's eyes can blink •The heart and blood vessels are fully formed •Fingers and toes should have fingerprints •Bone Marrow is now beginning to form •Heart is pumping 25 quarts of blood a day 99 Seventeen Weeks • Baby can have dream (REM) sleep • Baby's bones are hardening 102 Eighteen Weeks • Baby's ears now stand out from his head. 104 • 18 • weeks Fetal Development 98 Nineteen Weeks • Baby may be able to hear mother 107 Twenty Weeks • Baby recognizes its’ mothers voice • Baby weighs about 9 ounces • About six inches long • Baby is practicing swallowing • Baby can suck a thumb, yawn, stretch, and make faces • Baby can be felt moving and is called "quickening" • Earliest stage at which Partial birth abortions are performed 109 Fetal Development • 20 weeks 102 Credit: © Mediscan/Visuals Unlimited Human fetus in utero at 20-weeks. This 155-mm fetus appears to be sucking his/her thumb. 3593 Ultrasound • An ultrasound is generally performed for all pregnant women at 20 weeks of gestation • Doctor will confirm that the placenta is healthy • Attached normally • Baby is growing properly in the uterus • Baby's heartbeat and movement of its body, arms, and legs can also be seen on the ultrasound • Gender of the baby can usually be determined at 20 weeks 114 Twenty-one Weeks • Eyebrows are growing in. 116 Twenty-two Weeks • Tooth buds for baby • Adult teeth are in place now • Will survive childbirth 119 Twenty-three Weeks • Dance around -- baby may be able felt 121 Twenty-four Weeks •Baby's taste buds may be working now •Fetus weighs about 1.4 pounds now •Responds to sounds by moving or increasing its pulse •Jerking motions may be noticed if it hiccups •The inner ear fully developed •May be able to sense being upside down in the womb 123 Fetal Development • 24 weeks 118 Last week to get abortion in some states 119 Twenty-five Weeks • Baby's hair has color and texture 127 Twenty-six Weeks • Baby fat is building up under skin 129 Twenty-seven Weeks • Hiccups may be common from now on. 131 Twenty-eight Weeks •Fetus weighs about 2 pounds 6 ounces •Baby can open eyes and blink now •It changes position frequently at this point in pregnancy •Good chance of survival if baby is born prematurely now 133 Twenty-nine Weeks • Billions of neurons are developing in your baby's brain. 136 Thirty Weeks • Baby can sense a light on belly 138 Fetal Development • 30 weeks 133 Thirty-one Weeks • Baby can turn head from side to side 141 Thirty-two Weeks • Fetus weighs almost 4 pounds • Nails now cover the tips of your baby's toes and fingers • Baby's skin has less wrinkles as a layer of fat starts to form under the skin • May gain up to half its birth weight between now and delivery • Mother may start leaking colostrum from breasts, a yellowish fluid that precedes milk production 143 Thirty-three Weeks • Baby is losing that wrinkled alien look 148 Thirty-four Weeks • Baby's lungs are well developed 150 Thirty-five Weeks • Most physical development is complete. 152 Credit: © Dr. Daniel Logan/Visuals Unlimited Human Ultrasound showing fetus profile at 35 weeks. 144533 Thirty-six Weeks • Weight gain (about an ounce a day) is baby's top priority • Babies differ in size, depending on many factors (such as gender, the number of babies being carried, and size of the parents) • On average, it's about 12.5 inches and weighs 5.5 pounds • The brain has been developing rapidly • Lungs are nearly fully developed • The head is usually positioned down into the pelvis by now • Pregnancy is considered 'at term' once 37 weeks has been completed; baby is ready! 155 Thirty-seven Weeks • Baby is full term! 158 Thirty-eight Weeks • Little hands are ready to grip fingers. 160 Thirty-nine Weeks • The average baby weighs about 7 pounds now. 162 Forty Weeks • Baby's skull is flexible so it can squeeze through the birth canal. 164 Forty-one Weeks • Time to come out • due date marks the end of her 40th week • Pregnancy begins with implantation • Delivery date can be calculated using the first day of the last period • Pregnancy can last between 38 and 42 weeks with a 'full term' delivery occurring around 40 weeks. 167 Labor and Delivery • Triggered by cortisol (stress hormone) released by offspring • • • Offspring signals the end Prostaglandins are involved Estrogen increases/progesterone decreases • Allows uterine contractions • Oxytocin increases rate and strength of contractions 170 Labor and Delivery • Positive Feedback Mechanism • increased vaginal stretch causes more oxytocin (OT) release • which stimulates more contraction • which pushes baby • causing more stretch • more OT • more contraction • more stretch • more OT • more contraction (and so on) • baby is delivered / positive feedback cycle is broken 170 Vaginal Childbirth (Birth) 3D Video Animation Teratogens: “Monster Makers” Lead Tobacco smoking Alcohol Mercury Herbicides Radiation Ruebella Syphilis The fetus The pregnancy Baby's quality of life • Alcohol, recreational drugs, prescription medicines, viruses, bacteria, toxins, etc. • Any of the above can be teratogens and disrupt normal fetal development Health of mother 165 Fetal Alcohol Syndrome • Smaller heads • Deformed facial features • Abnormal joints and limbs • Poor coordination • Problems with learning short memories 166 Stages of Physical Development • • • • • • • • Neonate - “newborn” Infancy Toddlerhood Childhood Adolescence – puberty Adulthood Middle Age Advanced Age 168 Motor Development • Motor Development proceeds in a “down and out” fashion. • Head and arm control comes before leg and foot control. • Control also begins in the center of body then to extremities • Large muscle control precedes control of small muscles 169 Stages of Motor Development • Sits without support 5-6 months • Pulls to standing position 7-8 months • Crawls 10 months • Stands alone 11 – 12 months • Walks alone 12 months • Sequence of steps is fixed; the ages at which they occur are not fixed 170 Toddlerhood to Adolescence • During this period, physical growth continues, but at a slower rate than before. Eye-hand coordination improves dramatically. • During adolescence, a “growth spurt” occurs. Physical growth and development increases rapidly. • Puberty is the time when a person reaches sexual maturity. Around age 11 for girls and age 13 for boys. • Hormones of the endocrine system cause the onset of puberty 171 Sexual Maturity • Estrogens in females and androgens in boys (hormones) lead to the development of “secondary sex characteristics.” • Girls develop breasts, hips broaden • Menarche is the onset of menstruation (age 12-13) • Boys develop facial hair, voice deepens, ability to produce semen. • Onset of menarche was at about age 16 in 1880. This demonstrates the impact of environment (better diet, living conditions) on a genetically programmed event. 172 Adulthood • Not the same thing as sexual maturity • Some cultures have rituals that mark the transition to adulthood • Acceptance of socially defined responsibilities of adulthood. 173 Aging • Decline of physical strength, agility, other signs of aging begin in mid-twenties. • Menopause (around age 50 in women) is the cessation of ovulation & end of menstrual period. • No comparable period for men. 174 Aging and the Brain • Brain cells are lost with age • Neurons that remain “take up the slack” by increasing complexity. • Alzheimer’s disease about 1% of people 65 years of age and about 20% of 80 year olds. 175