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0answers
9 views

How did the double circulatory system evolve from the single circulatory system

I already learned how the mammal circulatory system (double circulatory system) evolved from the reptilian circulatory system. How did natural selection evolve the reptilian circulatory system and the ...
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1answer
33 views

How does the brain regulate its temperature?

I recently ran into a bio-physical paradox while trying to solve an engineering problem, using nature's way as a guide; namely the brain. I'm working on designing a totally new system of liquid/gas ...
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1answer
4k views

Why is the brain white?

I have read many articles about how the brain is the most power-hungry organ in any living complex organism, requiring about 70% of it's oxygen supplies in the resting state. Since the usual medium ...
3
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1answer
51 views

Is pulse rate measurable in the capillary bed and venous vasculature?

Pulse rate is easily felt when gently pressing the arteries in the wrist or neck region (Fig. 1). Fig. 1. Feeling the pulse at the radial artery. Source: Wikipedia Arteries supply the thin ...
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4answers
2k views

Will the heart keep beating if it is separated from the body?

The heart is a vital organ in our body, as it drives blood circulation. I was wondering if a heart keeps beating if it is separated from the body? If yes, then why?
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1answer
24 views

Who is organizing the heartbeat and its roles in the body?

Throughout the decades we heard that the heart is the only muscle whose nervous system is not acting. So who is he responsible for organising the heartbeat and its roles?
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1answer
34 views

Are there fish with a double circulatory system?

Our courseware materials say there are such fish, but the internet suggests fish only have a single circulatory system. Thanks!
10
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1answer
811 views

Where is the aneurysm in this picture?

I'm a curious person, I've never had any medical training, but I wish to know some more about aneurysms. Aneurysms are basically weakened spots in the elastic artery wall. This can eventually result ...
3
votes
1answer
91 views

Maximum RPM in zero-g before losing consciousness, spinning head-over-heels

There are more than a few scenes in Gravity that I find dubious. Specifically the ones where people are revolving very quickly, either about their own center of gravity or at the end of a rather long ...
3
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1answer
448 views

How does most of lymph get back into the blood stream? (I don't mean the lymphatic system)

I once read that it was because of osmotic pressure that it returns to the blood stream, by entering the venules. But why? If lymph originated as plasma how come that the solute concentration is ...
2
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1answer
161 views

Why is the Trendelenburg position used when placing and removing Central Venous Line catheters in the sub-clavian vein?

The title says it all. Why is it that patients are placed in the trendelenburg position when a catheter is inserted in the sub clavian vein? What would happen if the patient wasn't placed in the ...
3
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1answer
39 views

Thrombus and Embolii

Can treatment of thrombus cause embolism, in case of very high blood pressure, that may even lead to a heart attack ? As the very high Blood pressure may cause some of the enzymes not act completely ...
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1answer
489 views

In an open circulatory system, how is blood moved?

In the mollusks section, the powerpoint mentioned that gastropods and bivalves have an open circulatory system. According to the note, this means that the blood does not travel in vessels. How, then, ...
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1answer
81 views

Why are new vessels more permeable in microvasculature?

I know for microvasculature New microvasculature (arterioles, venules) are always more permeable as they lack pericytes. and then I have this sentence about new blood vessels (not specific) ...
2
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1answer
918 views

Valves in the heart

I am confused regarding the presence of valves in the superior vena cava. The superior vena cava does not possess valves unlike inferior vena cava, which possesses Eustachian Valve. Then where are ...
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0answers
49 views

What parts of the brain are involved in regulating blood pressure in mammals?

I'm reading this Wikipedia article on blood pressure and its regulation, and it mentions that medulla is involved. however, I vaguely remember reading another article on Wikipedia and it mentioned ...