BIO SCI 75 Lecture Notes - Lecture 17: Neural Tube Defect, Neural Tube, Anencephaly
Document Summary
Fetus is most susceptible to teratogens during the embryonic period. Neural tube defects: results when neural tube does not close properly, can range form mild to fatal, neurulation-neural tube forms form ectoderm. Fetus develops without parts of the brain or skull: upper part of the neural tube does not close all the way. Risk factors for neural tube defects: maternal diabetes, maternal obesity, radiation. Arsenic: cigarette smoking, de ciency in folic acid. Stages of labor and birth: dilation and effacement. Uterus and cervix widen, contractions begin and become more frequent: delivery of the fetus. Forceful uterine contractions begin, fetus is delivered: decidual reaction-placental birth. Three stages of birth: dilation of cervix. Expulsion: delivery of the infant: delivery of the placenta. Uterine contractions change in frequency and duration during labor: when contractions are ve minutes apart and one minute each and happen for an hour or more straight it is time to go to the hospital.
