Transcript Slide 1
Teratogens: • Any agent that causes structural abnormality to the fetus. • Whatever a mother ingests or inhales can end up in her blood and therefore the baby’s blood Does this look cool? A mother drinking while she is pregnant? Well, if she does, it is almost as if she has done this: Fetal Alcohol Syndrome • • • • • Alcohol is a teratogen Causes brain damage in developing baby They have trouble thinking/reasoning They have trouble getting along with others There is no safe time or amount that a woman can consume during pregnancy • No cure for this syndrome This is one of the results of alcohol on fetal development: 2. Smoking during Pregnancy • over 4000 chemicals • Constricts blood vessels causing deprivation of oxygen • Grow slower= smaller babies • More susceptible to infections 3. Cocaine use and other illegal drug use during pregnancy • • • • Increase risk of a miscarriage Premature labor Can cause irreversible brain damage Baby goes through withdrawal symptoms Placenta and Umbilical cord: Placenta: • organ that develops during pregnancy; links the blood supplies of a pregnant woman provides nutrients and remove waste products (chorionic villi) • Umbilical cord – The flexible cordlike structure connecting a fetus to placenta. Transports energy to the fetus and remove its wastes. Hormones involved in Birth of the Baby: • First Estrogen and Progesterone levels drop suddenly • Prostoglandins= (pituitary) hormones that cause the release of another VIP hormone called oxytocin - Both these hormones cause the uterus to contract which starts labor 1. Dilation stage- cervix widens, amnion breaks and the amniotic fluid is released (2-20 hrs). The cervix widens to approx. 10 cm. 2. Expulsion- contractions push baby into the birth canal. (0.5-2 hrs) 3. Placental Stage- after baby is born, placenta and umbilical cord are expelled from uterus (called afterbirth). • the umbilical cord is cut and now the baby will ingest food for nutrients and rid its own waste. Caesarean Section: • a c-section • surgical incision is made through a mother's abdomen and uterus • Done if baby is ‘rump’ first or if complications arise Lactation: • Secretion of breast milk • Begins within days after birth 1. Suckling stimulates nerve endings in nipple 2. Pituitary produces oxytocin 3. Oxytocin causes mammary lobules (in mothers breast) to secrete milk 4. Prolactin: hormone that is needed for milk production Twins- A Unique Occurrence 1. Fraternal Twins • Form when more than one egg is released from the ovaries. • Thus the twins can be different sexes • genetic make ups are different 2. Identical Twins • • • • Form from one egg Egg splits in two twins are the same sex with the same genetic material Technologies involved with this area of biology: 1. Ultrasound- a method of visualizing the internal parts of the body, or a fetus within the uterus, using sound waves. Obstetric ultrasound is primarily used to: Date the pregnancy Determine location of fetus Check the location of the placenta in relation to the cervix Check for the number of fetuses Check for major physical abnormalities. Assess fetal growth Check for fetal movement and heartbeat. Determine the sex of the baby 2. Amniocentesis • performed to determine if there are chromosomal or genetic disorders and certain birth defects. • involves inserting a needle into the amniotic sac to retrieve a sample of amniotic fluid. 3. Fetoscopy: • A procedure involving the passage of a thin endoscope through the mother’s abdomen and into the uterus to directly observe the fetus and placenta. 3. Chorionic Villi Sampling -CVS • A method of prenatal testing in which fetal cells from the fetal side of the placenta (chorionic villi) are extracted and analyzed for chromosomal and biochemical defects.