Answer to Question 1
Describe the two most common neural tube defects and what is known about their development.
Answer to Question 2
Proving that environmental contaminants cause reproductive damage is difficult, but evidence in wildlife is established and seems likely for human beings. Infants and young children of pregnant women exposed to environmental contaminants such as lead show signs of delayed mental and psychomotor development. During pregnancy, lead readily crosses into the placenta, inflicting severe damage on the developing fetal nervous system. In addition, infants exposed to even low levels of lead during gestation weigh less at birth and consequently struggle to survive. For these reasons, it is particularly important that pregnant women receive foods and beverages grown and prepared in environments free of contamination.
Mercury is another contaminant of concern. Fatty fish are a good source of omega-3 fatty acids, but some fish contain large amounts of the pollutant mercury, which can impair fetal growth and harm the developing brain and nervous system. Because the benefits of seafood consumption seem to outweigh the risks, pregnant (and lactating) women need reliable information on which fish are safe to eat.
Gallbladder with gallstones. Note the stones in the hepatic duct, gallbladder, and common bile duct.
Rhytidoplasty. This is a common form of plastic surgery in which the skin is pulled and sutured to d
Common patient positions.
Summary of Drug Action: Common Routes of Administration
Stages of development in vertebrates.
Davis’s U-tube experiment