Circulation Flashcards
Where does the foramen ovals go from and too? (2mks)
Right atrium to left atrium
Where does the Ductus venosus go from and too? (2mks)
Portal vein to inferior vena cava
Where does the ductous arteriousus go from and too? (2mks)
Pulmonary artery to aorta
Where do the hypogastric arteries go from and too? (2mks)
Descending aorta to umbilical arteries
Why is the foramen ovals a useful adaption? (1mk)
It helps blood bypass the lung circulation so it can go straight to vital organs
Why is the ductous venosus a useful adaptation? (1mk)
It connects the placenta to the fetus allowing oxygenated blood to go to the fetus
State 3 other adaptations the fetus has to compensate for the slightly hypoxic in utero environment (3mks)
- fetal HB has a higher affinity to oxygen so more HB binds to O2 otherwise less O2=less nutrients=IUGR
- has a higher amount of RBCs and a higher HR
What is fetal oxygenation dependent on? (2mks)
- maternal oxygenation
- maternal blood flow
- placental function
- fetal circulation
What does variability show on a CTG? (2mks)
The interplay between the sympathetic and parasympathetic nervous system good variability is an indicator of a healthy autonomic nervous system
What does a drop in oxygen cause chemoreceptors to do? (2mks)
They stimulate sympathetic activity via cardioregulatory and release adrenaline causing HR to increase
What do barorecpetors do if they detect a rise in BP? (2mks)
They stimulate the vagus nerve via the parasympathetic system causing the HR to drop
Where does oxygenated blood go after it has gone through the foramen ovale? (2mks)
It goes to the vital organs and some of it goes to the aorta to travel to the upper body via coronary/carotid arteries
Where does deoxygenated blood go after travelling through the ductus arteriosus? (3mks)
It goes through the pulmonary artery and then down the descending aorta through the hypogastric arteries and umbilical arteries until it reaches the placenta again
The red blood cells of a fetus have fetal haemoglobin how is this different to adult haemoglobin? (1mk)
Has a higher affinity for oxygen
Umbilical arteries carry this type of blood (1mk)
Deoxygenated
