1. Fetal circulation By: Asmaa mashhour eid Supervised: Dr Aida abd-alrazk

2. Objective: 1-summarize anatomuy cardiovascular fetus 2-explian what heart rate fetus affected 3-define different aspects in fetal circulation 4-explain fetal circulation intrauterine

3. 5-explain fetal circulation extrauterine 6-describ fetal hemoglobin and differs from adult 7-summary 8-referans

4. Cardiovascular system -first systems become functional in intrauterine life -simple blood cell joined to the walls of the yolk sac progress to become a network of blood vessels and single heart tube which forms as early as the 16 th of day of life

5. -heart beats as early as the 24 th day -heart divides four chambers 6 th or 7 th week (two atrium and two ventricle ) -heart begin to develop in the 7 th week Cont

6. Fetal circulation intrauterine -umbilical vein transports blood rich in O2 and nutrients from the placenta to the fetal body

7. -This divides into two inside the body of the fetus 1-one branch goes to the liver 2- other called ductus venosus -ductus venosus joins inferior vena cava, which carries deoxygenated blood to the right atrium

8. -As the blood from the inferior vena cava enters the right atrium, a large proportion of it is shunted directly into the left atrium through an opening called the foramen ovale.

9. -the foramen ovale helps prevent blood from moving in the reverse direction

10. -The right atrium also receives deoxygenated blood from the upper parts of the body through the superior vena cava -enters the right ventricle and then pumped into the pulmonary artery.

11. -. In the fetus the pulmonary artery is connected to the descending aorta by a blood vessel called ductus arteriosus -Most of the blood in the pulmonary artery bypasses the lungs by entering a fetal vessel the ductus arteriosus

12. -Because there is no point in pumping blood into the lungs most of the blood in the pulmonary artery in shunted across the ductus arteriosus into the aorta -This blood contains less oxygen than that pumped by the left ventricle and supplies the lower parts of the body

13. -The umbilical cord also contains two umbilical arteries. These arteries contain deoxygenated blood from the fetus into the placenta completing the cycle.

15. Fetal circulation extrauterine -after birth the umbilical cord is clamped and cut -Inflation of the lungs reduces the resistance to blood flow through the lungs resulting in increases blood flow from the pulmonary arteries

16. -an increased amount of blood flows from the right atrium to the right ventricle and into the pulmonary arteries and less blood flows through the foramen ovale to the left atrium

17. -increased volume of blood returns from the lungs through the pulmonary veins to the left atrium, which increases the pressure in the left atrium.

18. -ductus arteriosus starts shrinking and functionally closes by about 72 hours of life and anatomically closes within a few weeks

20. Heart rate fetal affected: 1-fetal oxygen level 2-body activity 3-circulation blood volume

21. Fetal hemoglobin -The concentration of hemoglobin in fetal blood is about 50 % greater than in maternal blood.

22. -Fetal hemoglobin is slightly different chemically and has a greater affinity for O2 than maternal hemoglobin.

23. -fetal hemoglobin can carry 20- 30% more O2 than maternal hemoglobin

24. Difference between fetal and adult hemoglobin * fetal hemoglobin composition (two alpha and two gamma chains)

25. Cont *adult hemoglobin composition (two alpha and beta) * hemoglobin form at birth that newborn about (17g/100 ml) * adult hemoglobin normal level (11g/100ml)

26. Cont *fetal hematocrit is about 53% * adult hematocrit about 45%

27. Summary: - fetal circulation difference about adult circulation - fetal circulation intrauterine depend on mother - fetal circulation extrauterine develop gradually - fetal hemoglobin difference adult hemoglobin

28. Reference: 1- Book (maternal and child health nursing) fifth edition (Adele pillitteri) pages (190,191,191) 2- internet www.homebusinessandfamilylife.co m