From Conception to Birth Pregnancy From Conception to Birth
What happens during conception? Sperms’ journey Ovulation Passage to Fallopian Tubes Conception: Egg to Embryo
Ovulation video http://www.mayoclinic.org/healthy-lifestyle/womens-health/multimedia/ovulation/vid-20084729
Fertilization During sexual intercourse the penis becomes erect for the transfer of sperm into the vagina. After intercourse, the sperm cells swim through the female reproductive tract and enter the oviducts. If they meet with an egg in the oviduct, egg and sperm cell may unite. The fusion of a sperm cell nucleus and an egg cell nucleus is known as fertilization A fertilized egg is known as a zygote.
Fertilization Fertilization generally occurs when the egg is in the upper portion of the oviduct. If the egg is not fertilized within about 24 hours after ovulation, it breaks down and disappears. Six to ten days later, the resulting zygote may become implanted (attached) in the lining of the uterus.
What happens during conception? Fertilization – sperm meets egg Cells begin to divide Implantation Fetal Development
Fertilization
The Human Zygote Fertilization Two Cells Four Cells Implantation Morula Stage Blastocyst Stage
Prenatal Development When the fertilized egg arrives in the uterus, it implants itself in the thickened, spongy uterine wall. After eight weeks of development the embryo is called the fetus. The period of time between the fertilization of the egg and the birth of the offspring is called gestation In humans the gestation period is nine months or approximately 266 days.
Human Gestation http://www.medicinenet.com/fetal_development_pictures_slideshow/article.htm
Fetal development: Divided into 3 trimesters First trimester=0-14 weeks
Embryo-cluster of cells that develop between the third and eight week. About ¼ inch long
4 – 6 Weeks Placenta can be seen Baby floats in amniotic sac This sac protects the baby from bumps from outside world Heart starts beating Embryo size of a pea CNS developing including the spine Eyes forming
Placenta The amniotic sac is the sac that surrounds the baby and protects it Placenta-thick blood rich tissue that lines the walls of the uterus during pregnancy and nourishes the embryo Inside cord: three vessels; one large vein carrying O2 blood and nutrients to baby 2 smaller arteries carrying carbon dioxide and wastes from baby to placenta
6- 7 weeks Arms and legs take shape Embryo starts to move Ear buds forming Teeth forming Palate (roof of mouth) forming CNS still developing
Fetus-developing group of cells after the 8th week Eyes, ears, nose and mouth form Placenta and umbilical cord have developed Almost an inch long About the size of a grape (9 weeks)
8 - 9 weeks (2 – 2 ½ months) Arms and legs are lengthening External reproductive organs starting to form (men determine the sex of the child) Big vein in umbilical cord carries blood that brings water, oxygen and nutrients from mother Smaller veins carry away wastes
2nd trimester=15-28 weeks 16 weeks-fetus can blink, eyebrow & eyelash develops, can grasp and kick 21 weeks-fetus can hear conversations about 12 inches long May survive if born after 24 weeks, but need special medical care (pic on left 24 weeks)
3 months Only three inches long but looking like a baby Bones are growing Now considered a FETUS Baby very flexible Lots of cartilage
4-5 months Mother can start to feel baby move Eyelids still closed Baby can start to hear nearby sounds Baby might be able to survive if born now The fetus is the size of a squirrel Miscarriage is an expulsion of a fetus BEFORE the 20th week. Fetus can feel pain.
6 months (24 weeks) Viable to survive if born CNS still developing Fetus can control digestion 300 bones, not fused Lots of wrinkles Sleeps and wakes in cycles
Third Trimester-29 weeks to birth Fetus uses all five senses. Pass water from the bladder Some fetuses dream in 8th and 9th month.
7 – 9 months (28 – 36 weeks) Fetus is adding layer of fat to cushion self Cerebral cortex developing
http://www.nytimes.com/interactive/2013/06/18/us/politics/abortion-restrictions.html?_r=0
Summary of Human Development
https://www.youtube.com/watch?v=-TXkZ_sjyUk
Twins Identical twins Single egg fertilized by single sperm and it splits in two. Same gender, look alike, etc. because same genetic material. Fraternal twins Female’s ovaries release two eggs Each twin has different genetic make-up and can be a different sex and look different. (similar to siblings) More common than identical
How twins form
Twins in Utereo
Identical vs. Fraternal Twins
Pregnant with twins & triplets
Twins at birth
Co-joined twins (Siamese Twins) Chang & Eng Bunker of Siam
In Vitro Fertilization It is now possible for fertilization to take place outside the human body (in vitro). The fertilized egg is then implanted in the uterus so that development can occur. What commonly results in: Four offspring - quadruplets Five offspring - quintuplets Six offspring - sextuplets Seven offspring - septuplets Eight offspring - octuplets Nine offspring - nonuplets Ten offspring - decuplets
Stages of labor:
Stage 1: Dilation Contractions of uterus cause cervix to widen Amniotic sac breaks that surrounds baby
Effaced
Stage 2:Passage through birth canal Cervix is fully dilated Emerges from mother’s body Right after baby takes its first breath. Cries to clear amniotic fluid out of lungs.
Stage 3: Afterbirth Placenta (afterbirth) is delivered Umbilical cord is cut to separate placenta and baby.
Postnatal Development Following birth, the placenta is discarded from the mother’s body and the mother begins producing milk from mammary glands located in the breasts. The mother’s breast milk is normally the best natural food for a newborn baby.
Developmental Disabilities During pregnancy, essential that the expectant mother provide good prenatal care by: eating nutritious foods, avoiding alcohol, tobacco, and drugs receiving proper medical attention regularly. Using Alcohol, Tobacco or drugs may cause: low birth rates, premature births, Fetal Alcohol Syndrome Other birth defects.
Alcohol During Pregnancy When a pregnant woman drinks, so does her baby. The baby's growth can be altered and slowed. The baby may suffer lifelong damage. Drinking during the first few weeks, when many women don’t know they are pregnant, can be especially harmful to the baby’s CNS.
Fetal Alcohol Syndrome (FAS) FAS – A group of mental and physical birth defects caused by a women drinking alcohol during her pregnancy.
The Signs and Symptoms of FAS PHYSICAL SYMPTOMS Small head and identifiable facial features. Abnormal or deformed limbs, hands or feet. Heart, liver and kidney problems Vision and hearing problems. MENTAL SYMPTOMS Slow growth and coordination. Difficulty staying focused, Difficulty recognizing and understanding patterns, Difficulty predicting "common sense" outcomes Difficulty mastering math and reading
How much alcohol is safe to drink for a pregnant women ? FAS is not just in children of mothers who abuse alcohol or are heavy drinkers. The latest research shows that as little as two drinks in early pregnancy or four drinks all at once (a binge episode) can kill developing brain cells. Many people believe an "occasional" drink during pregnancy is safe. NOT TRUE!! For that reason, no amount of alcohol is considered safe for a pregnant woman!!!
Preventing FAS/FAE Drinking alcohol during pregnancy is the leading causes of mental retardation in the world. FAS is totally preventable!! There is no safe amount of alcohol to drink!! No safe time in which to drink it!! Even small amounts can harm the fetus
Other Complications: Miscarriage-spontaneous expulsion of a fetus that occurs before the 20th week of pregnancy. Stillbirth-a dead fetus expelled from the body after the 20th week of pregnancy. Ectopic pregnancy-zygote implants in fallopian tubes, abdomen, ovary or cervix. Needs to be removed. Preeclampsia-prevents placenta from getting enough blood. May result in low birth weight. Symptoms are high blood pressure, swelling, high protein in urine. Treatment is medicines and bed rest.
http://www.medicinenet.com/conception_pictures_slideshow/article.htm