Portal hepatic vein. Foetal circulation

Vascular Structures in Liver Detailed Anatomy, continued … Vascular Structures in Liver 1. Largest vessels are portal vein and IVC a. Portal Vein: 1. appears on T.S. as tubular, echolucent structure 2. courses horizontally from porta hepatis

3. walls echogenic due to structures in portal triad Detailed Anatomy, continued … 3. walls echogenic due to structures in portal triad b. Left Portal Vein: 1. has more variable course 2. May be difficult to trace on transverse scans

Hepatic Vessels IVC Right Portal Vein Left Portal Vein Main Portal Vein

2. extends into right lobe 3. branches after porta hepatis Vascular Structures, continued … c. Right Portal Vein: 1. anatomical landmark 2. extends into right lobe 3. branches after porta hepatis 4. L.S. shows “dumbbell” or circular structure with echogenic “collar”

Computer-enhanced image of RPV, L.S.

Computer-enhanced 3-D image of RPV, L.S.

2. Appears to pass through liver Vascular Structures, continued … d. IVC: 1. To right of aorta 2. Appears to pass through liver 3. Diameter enlarges after renal veins join (~L-1)

Computer-enhanced 3-D image of Hepatic Vessels

c. In superior half of liver Vascular structures, continued … 2. Hepatic Veins: a. Tubular structures b. Enlarge cephalad c. In superior half of liver d. Angles of hepatic vein branches oriented toward IVC e. Walls not echogenic

Hepatic Veins R. Hepatic Vein Middle Hepatic Vein L. Hepatic Vein

Fetal Circulation Embryonic lungs and digestive tract nonfunctional Respiratory functions and nutrition provided by placenta

Placental Blood Supply Figure 21-33a

Placental Blood Supply Blood flows to the placenta: through a pair of umbilical arteries which arise from internal iliac arteries and enter umbilical cord

Placental Blood Return Blood returns from placenta: in a single umbilical vein which drains into ductus venosus Ductus venosus: empties into inferior vena cava

The Neonatal Heart Figure 21-33b

Before Birth Fetal lungs are collapsed O2 provided by placental circulation

At Birth Newborn breathes air Lungs expand Pulmonary circulation provides O2

2 Fetal Pulmonary Circulation Bypasses Foramen ovale: interatrial opening covered by valve-like flap directs blood from right to left atrium Ductus arteriosus: short vessel connects pulmonary and aortic trunks

Cardiovascular Changes at Birth Pulmonary vessels expand Reduced resistance allows blood flow Rising O2 causes ductus arteriosus constriction Rising left atrium pressure closes foramen ovale

Congenital Cardiovascular Problems Figure 21-34

Congenital Cardiovascular Problems Develop if proper circulatory changes do not occur at birth

Thank you for attention !