Bmat 2018 biology


Hey! Can someone please explain me why the answer for 1 is incorrect? If not from the coronary vessels, where does the heart get the glucose from? And may I please know why the answer for no 2 is correct?
Thanks in advance !!

The site of diffusion is the capillaries, not the artery. It’s a common trick and this is why it’s very important to highlight these words and illustrate everything!

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Thank you so much for explaining Ari! Another thing is in the cardiac video lesson, I heard the coronary arteries are closed by a flap as the blood pumps out of the major arteries like aorta and the heart does not get the blood when the pressure is high. Can you please explain why no 2 is correct in this question? Thanks again !!!

hey here’s your answer for question 2:

it’s another trap!

if you go too fast on the question you’ll remember that blood flows in the coronary arteries in ventricular diastole when the semi-lunar valves are closed, so you’d think that the aortic pressure is lower as we are in diastole.

BUT: if you look at the heart cycle diagram (Ari’s lessons [BIO-4] Cardiac cycle), you see that the Aortic pressure has a slight spike right after the semi-lunar valves close due to back flow.
This means there’s still high pressure in the Aorta even though we’re in diastole.

Hope this helps!

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Hey! Thank you so much for your explanation :two_hearts:. I got it now !

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