Is this really "High Yield" ?

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Blood coming through the umbilical vein is shunted around the liver through the:

A. Aorta
B. Foramen Ovale
C. Ligamentum venosum
D. Ductus Venosus

I never even heard of any of the answer except for A lol...
 
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It's the ductus venosus and it deals with fetal circulation. I don't know whether it's high yield or not but it's definitely good to know how fetal circulation differs from adult circulation. Just know that in the fetus, the lungs and liver are non-functional, obviously. You might then ask yourself, how is the blood circulated? How this works is OXYGENATED BLOOD from the mother enters through the umbilical VEIN and goes straight to the tissue, bypassing the LIVER (via the DUCTUS VENOSUS) and LUNGS (via the FORAMEN OVALE). DEOXYGENATED BLOOD from the tissue returns to the right atrium to the pulmonary artery and bypasses the LUNGS (via the DUCTUS ARTERIOSUS) before it returns to the placenta via the 2 umbilical arteries. The mother then oxygenates the blood for the fetus and the process repeats.
 
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EK didn't cover it at all but somehow they TESTED on it in EK Bio 1001. Every other prep company discusses it. It's fairly simple so I'd memorize it.
 
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I don't know if it's considered background knowledge or not but it's definitely covered in the Princeton books. It might even be covered in the EK books now that I think about it. I'll have to double check on that. Don't fret over it though. It's really simple if you sit there and picture it. Just pretend your wife (or future wife) is having a baby or something and you're trying to figure out how your baby is breathing 🙂. It really puts things in perspective and helps you learn it forever, not just for this test. This video might help you out. http://www.youtube.com/watch?v=OV8wtPYGE-I.
 
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EgyptianDoc said:
It's the ductus venosus and it deals with fetal circulation. I don't know whether it's high yield or not but it's definitely good to know how fetal circulation differs from adult circulation. Just know that in the fetus, the lungs and liver are non-functional, obviously. You might then ask yourself, how is the blood circulated? How this works is OXYGENATED BLOOD from the mother enters through the umbilical VEIN and goes straight to the tissue, bypassing the LIVER (via the DUCTUS VENOSUS) and LUNGS (via the FORAMEN OVALE). DEOXYGENATED BLOOD from the tissue returns to the right atrium to the pulmonary artery and bypasses the LUNGS (via the DUCTUS ARTERIOSUS) before it returns to the placenta via the 2 umbilical arteries. The mother then oxygenates the blood for the fetus and the process repeats.
Click to expand...

Nice recap. 👍


By the way, I think your new avatar is very fitting.
 
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EgyptianDoc said:
It's the ductus venosus and it deals with fetal circulation. I don't know whether it's high yield or not but it's definitely good to know how fetal circulation differs from adult circulation. Just know that in the fetus, the lungs and liver are non-functional, obviously. You might then ask yourself, how is the blood circulated? How this works is OXYGENATED BLOOD from the mother enters through the umbilical VEIN and goes straight to the tissue, bypassing the LIVER (via the DUCTUS VENOSUS) and LUNGS (via the FORAMEN OVALE). DEOXYGENATED BLOOD from the tissue returns to the right atrium to the pulmonary artery and bypasses the LUNGS (via the DUCTUS ARTERIOSUS) before it returns to the placenta via the 2 umbilical arteries. The mother then oxygenates the blood for the fetus and the process repeats.
Click to expand...

question... does the oxygenated blood physically go to the fetus or does oxygen diffuse through placenta... because now you got me confused....

i am pretty sure it diffuses through...
 
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Haha, isn't it great? Hopefully we can all put it to action and kill this test. You'd think with the doctor shortage they'd ease up a little bit. This is completely way off topic but here's a quick story if you care. So, I was on a flight last week and the gentleman sitting behind us recognized my dad. He was an anesthesiologist who used to do surgeries with my dad ten years ago. We had a long chat about the MCAT and how different it was back in 1985 when he took it. He mentioned that he was dyslexic and managed a 6 in a section of the MCAT. I think all of this goes to prove that if you always do your best and put your heart and soul into really becoming a doctor, you can and will do it, no matter what. Nothing can hold you back! Anesthesiology is one of the most competitive fields you can get into. I really believe that this test keeps a lot of genuinely good people from becoming doctors and I hate to see it. Just keep working hard and you will kill this test. Even if you don't it's not the end of the world. You will be a great doc someday. There's your motivation for the day. Now get back to studying 🙂
 
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phibe1 said:
question... does the oxygenated blood physically go to the fetus or does oxygen diffuse through placenta... because now you got me confused....

i am pretty sure it diffuses through...
Click to expand...


Oxygenated blood from the placenta enters the fetus via the umbilical vein.

It does not diffuse.


Don't forget that fetal hemoglobin has a higher affinity for oxygen than the mothers, this promotes oxygen exchange to the fetus. Basically, it's a way to ensure that the baby gets enough O2, even if the mother has a low [O2]. 😉
 
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phibe1 said:
question... does the oxygenated blood physically go to the fetus or does oxygen diffuse through placenta... because now you got me confused....

i am pretty sure it diffuses through...
Click to expand...

The placenta surrounds the fetus but the umbilical cord (which is an extension of the placenta) is what actually brings the oxygenated blood to the fetus and returns the deoxygenated blood to the mother.

Sorry if I confused you but just picture what I said. I assure you it's right. And use this site it might help: http://www.indiana.edu/~anat550/cvanim/fetcirc/fetcirc.html.
 
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EgyptianDoc said:
Haha, isn't it great? Hopefully we can all put it to action and kill this test. You'd think with the doctor shortage they'd ease up a little bit. This is completely way off topic but here's a quick story if you care. So, I was on a flight last week and the gentleman sitting behind us recognized my dad. He was an anesthesiologist who used to do surgeries with my dad ten years ago. We had a long chat about the MCAT and how different it was back in 1985 when he took it. He mentioned that he was dyslexic and managed a 6 in a section of the MCAT. I think all of this goes to prove that if you always do your best and put your heart and soul into really becoming a doctor, you can and will do it, no matter what. Nothing can hold you back! Anesthesiology is one of the most competitive fields you can get into. I really believe that this test keeps a lot of genuinely good people from becoming doctors and I hate to see it. Just keep working hard and you will kill this test. Even if you don't it's not the end of the world. You will be a great doc someday. There's your motivation for the day. Now get back to studying 🙂
Click to expand...

I hear you, man!

Chuck's Right Foot said:
http://www.aamc.org/students/mcat/preparing/bstopics.pdf

Supposed to cover the whole list of topics...
Click to expand...


Fetal circulation is not listed there.
 
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Yeah I dont think we have to know fetal circulation. Great recap though. I sure this information could easily be present on a passage in embryo development though.
 
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Just remember the blood does not mix. That seems to be asked in practice tests or questions from multiple review sources. The foramen ovale might be worth knowing, since that concept isn't too overly difficult and be applied to multiple different types of BS passages, such as development or physiology (anatomical shunt).

In terms of the original question OP you would have to use process of elimination there, especially if it wasn't passage based. The aorta obviously isn't a shunt, the foramen ovale deals with shunting the fetal lungs, I've never heard of ligamentum venosum and almost sounds like one of those made up MCAT choices that sounds reasonable but is simply fantasy, which leaves us with ductus venous as the only answer choice. That'd be my personal strategy for that question if it was a discrete since they're all unfamiliar terms with the exception of the aorta and foramen ovale.
 
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Ooooh, oohhh!! I know this one! (sorry if this has been said before, got so excited didn't even read the other replies). The ductus venosus shunts from away from the fetal liver! Lol, that is curtousy the Kaplan bio flashcards 😀 I'm sure no one else gets the excitement, but bio is my worst section, so I'm glad to know about the circulatory system, hemoglobin, and fetal circulation 😀

PS. The foramen ovale diverts blood away from the pulmonary artery and to the left atrium, and the ductus arteriosus shunts blood directly from the pulmonary artery to the aorta. Also, I think the only other important thing would be that fetal hemoglobin has a higher affinity for oxygen.
 
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Ugh.... I was looking forward to not having to know fetal physiology. Oh well, I'll add it to my endlessly increasing list.
 
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vandyam said:
Ooooh, oohhh!! I know this one! (sorry if this has been said before, got so excited didn't even read the other replies). The ductus venosus shunts from away from the fetal liver! Lol, that is curtousy the Kaplan bio flashcards 😀 I'm sure no one else gets the excitement, but bio is my worst section, so I'm glad to know about the circulatory system, hemoglobin, and fetal circulation 😀

PS. The foramen ovale diverts blood away from the pulmonary artery and to the left atrium, and the ductus arteriosus shunts blood directly from the pulmonary artery to the aorta. Also, I think the only other important thing would be that fetal hemoglobin has a higher affinity for oxygen.
Click to expand...

...but...the foramen ovale shunts blood from the RIGHT ATRIUM to the left atrium. Not from the pulmonary artery. 😱

btw, would anyone know if the nephron is still high-yield?
 
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muhali3 said:
...but...the foramen ovale shunts blood from the RIGHT ATRIUM to the left atrium. Not from the pulmonary artery. 😱

btw, would anyone know if the nephron is still high-yield?
Click to expand...


Yes!!! Know that ****e!!! In and out, man. The nephron or it's peripheral affects/both at the nephron and by other systems on the nephron (urine, ion flow, adh, etc.) have been on almost all of my practice exams.
 
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