Author Question: Discuss the role of the placental blood barrier. What will be an ideal ... (Read 75 times)

rosent76

  • Hero Member
  • *****
  • Posts: 516
Discuss the role of the placental blood barrier.
 
  What will be an ideal response?

Question 2

List the stages of development from conception to birth.
 
  What will be an ideal response?



kxciann

  • Sr. Member
  • ****
  • Posts: 356
Answer to Question 1

The placental blood barrier divides the mother's blood from the fetal blood supply. The barrier prevents mixing of maternal and fetal blood cells but permits movement of tiny molecules of nutrients, gases, and waste materials. The movement of most potentially harmful substances from the mother to the fetus is prevented. Some disease-causing substances are known to be transmitted from mother to fetus, often causing birth defects or premature death. Microorganisms such as the rubella virus, HIV, and the bacteria Toxoplasma gondii, substances such as alcohol, and drugs such as Thalidomide cross the placental blood barrier and cause fetal infection or birth defects. Other toxins or microorganisms cross the placental blood barrier during birth when the placenta is torn during the birth process and maternal and fetal blood is mixed.

Answer to Question 2

Zygote, from gamete union to two days later
Embryo, from two days to eight weeks
Fetus, from eight weeks to birth
Neonate, at birth



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

Hypertension is a silent killer because it is deadly and has no significant early symptoms. The danger from hypertension is the extra load on the heart, which can lead to hypertensive heart disease and kidney damage. This occurs without any major symptoms until the high blood pressure becomes extreme. Regular blood pressure checks are an important method of catching hypertension before it can kill you.

Did you know?

In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.

Did you know?

When taking monoamine oxidase inhibitors, people should avoid a variety of foods, which include alcoholic beverages, bean curd, broad (fava) bean pods, cheese, fish, ginseng, protein extracts, meat, sauerkraut, shrimp paste, soups, and yeast.

Did you know?

Drug abusers experience the following scenario: The pleasure given by their drug (or drugs) of choice is so strong that it is difficult to eradicate even after years of staying away from the substances involved. Certain triggers may cause a drug abuser to relapse. Research shows that long-term drug abuse results in significant changes in brain function that persist long after an individual stops using drugs. It is most important to realize that the same is true of not just illegal substances but alcohol and tobacco as well.

Did you know?

All adults should have their cholesterol levels checked once every 5 years. During 2009–2010, 69.4% of Americans age 20 and older reported having their cholesterol checked within the last five years.

For a complete list of videos, visit our video library