foetal circulation Flashcards
where is the placenta usually located?
in the posterior funded of the uterus
what vessels carry oxygenated and nutrient rich blood away from the placenta to the foetus?
umbilical veins
where does the smaller branch of the umbilical vein go to?
the liver
where does the larger branch of the umbilical vein go to?
it by-passes the liver and drains straight into the inferior vena cava as the DUCTUS VENOSUS
what happens to the blood from the DUCTUS VENOSUS before it reaches the right atrium?
it mixes with venous blood from the lower limbs
what happens to most of the blood entering through the inferior vena cava?
most of the blood passes into the left atrium through the foramen ovale, then into the left ventricle, then aorta
what happens to the remainder of the blood entering the heart through the inferior vena cava?
it passes to the lungs via the right ventricle
what valve directs the blood to the foramen ovale?
the valve of the inferior vena cava
what is the name of the inter-atrial septum that has the foramen ovale?
septum secundum
what is the name of the inter-atrial septum which has the foramen secundum?
septum primum
from the PULMONARY TRUNK, where does 90% of the blood go?
to the DUCTUS ARTERIOSUS, which then joins the descending aorta
from the PULMONARY TRUNK, where does 10% of the blood go?
to the lungs via the pulmonary veins
where does 2/3 of the blood go from the descending aorta?
to the placenta via the internal iliac artery then the umbilical artery
where does 1/3 of the blood go from the descending aorta?
to the abdomen, pelvis and lower limbs
what is the first shunt in foetal circulation?
the ductus venosus
