Questions tagged [blood-circulation]

Tag for questions regarding the circulation of blood through out the organism and issues that may arise from dysfunction of systemic circulation.

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45 views

How much does capillary action contribute to blood flow to the human brain?

The BBC News Universal Wonders short video Why water is one of the weirdest things in the universe says after 01:50: Water molecules can float upwards against ...
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Did our late Cryogenian ancestor have a heart?

If I'm correct, our Cryogenian selves might be somewhere between the Urbilaterian and the Protostome-Deuterostome ancestor (many age estimates of PDA here). Reconstructions of the former's anatomy ...
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How are monocytes larger than capillaries?

I have read that the average size of a capillary is about 8 micrometers. How is it possible that the 15 micrometer or so monocytes in blood do not block these vessels? https://en.m.wikipedia.org/wiki/...
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increase in blood pressure can in turn decrease it?

increase in blood pressure can actually decrease it? bp=co*TP and cardiac output (co) decreases when after load increases, because with the increase of the after load, stroke volume decreases. ...
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Cardiac cycle and atrial contraction

During atrial contraction ("a" in the figure), why does the ventricular pressure match the atrial pressure? The ventricular pressure generally stays the same throughout passive filling until it ...
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Why does muscle blood flow decrease during exercise?

My questions semi-relates to these two items: Where does extra blood come from to fill your muscles during exercise? , and Blood pressure during exercise . While reading Exercise Physiology by Dr. ...
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Coronary circulation

It is said that the coronary artery that gives the posterior descending artery(PDA) determines if the heart is right dominant(most cases) or left dominant. Is there any reason to this? Why PDA?
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Mechanism of redirected blood

I've read several fitness articles mentioning redirected blood flow to muscles that are in use. However, they never mention how it works. Is it local and specific to the muscles in use? Or, for ...
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When endothelial cells in blood vessels (arteries or veins) are damaged, does atheroma form first or blood clot?

I have learnt from Khan Academy's video on atheresclerosis that when the endothelial cells of an artery are damaged, atheroma forms at the site, and if the atheroma’s fibrous cap is ruptured, ...
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Why is urea not converted to ammonia in the body?

After the liver processes metabolites to produce urea and other by-products, these travel in the blood to the heart, then they are oxygenated, and some travel through the renal artery to the kidneys. ...
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How do veins's valve pocket sinus tend to become hypoxic?

For context, this question relates to the formation of deep vein thrombosis as I read that hypoxemia in vein can trigger coagulation cascade and cause a thrombus to form in vein. I read that vein's ...
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Cardiopulmonary reflex

Cardiopulmonary receptors (CPR) locate in the junction of great veins (IVC/SVC/PV) to atria. They are also known as low-pressure receptors. They detect the increase of preload to atria. Statement 1: ...
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Reaction of the body to heat

In massage school we are being taught hydrotherapy -- applying cold and heat to specific areas. It says that when applying cold, first the body goes through vasoconstriction, and then later ...
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Why does atheroma contain thromplastin/tissue factor?

From my understanding, when the endothelial lining of arteries is damaged, atheroma is formed at the site of the damaged area. If the atheromas is ruptured, thromboplastin contained in atheroma is ...
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The detail about the exact time of heart attack

Storage of cholesterol in coronary artery tends to heart attack. But in which phase heart attack occurs? Why only a definite time is called heart attack? Why this is the extreme point of coronary ...
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Typical concentration of oxygen for hypoxia and necrosis due to lack of nutrients

I'm a physicist and I'm interested in hypoxia due to the lack of nutrients at the center of avascular tumors. So I have a few questions about hypoxia. Below which concentration of oxygen and other ...
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134 views

Why are veins not blocked by plaques?

In my textbook, it is written that atheromatous plaques block the artery. This leads to heart attack and and heart failure. But my question is why do the plaques only block arteries and not the veins? ...
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Do fat people have more chances of developing nitrogen bends?

I was reading some text on deep sea physiology. I got to know that solubility of nitrogen in fat is five times that in water. The exact text from the book animal physiology adaptation and environment ...
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1answer
108 views

What are the effects of oxygen toxicity in human blood?

I was reading some text on deep sea Physiology, and for to know that diving to do could cause oxygen toxicity in the blood. This was the exact text from the book Textbook of Medical Physiology by ...
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Why are higher doses of atropine required to produce central effects?

Reason given in my book is restricted entry into the brain..is it something to do with the chemisty?
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In adverse effects of Heparin, why is bleeding from deeper organs more common?

The reason given in my book is that it i because it interferes with the secondary hemostasis..but i did not understand how that implies that bleeding from deeper organs is more common..
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48 views

Does blood carry metallic nanoparticles?

I find this particular chart about constituents of blood very informative and interesting. Looking through the different components, I see metals such as copper, zinc, etc. Are these only carried as ...
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How does vasodilation slow blood flow?

During inflammation, cytokines and histamine cause vasodilation to increase blood flow to the inflamed area. However, it is also said that vasodilation slows blood flow which facilitates the adhesion ...
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52 views

Blood pressure in the blood vessels

Why do the capillaries have a lower blood pressure than the arteries even though the capillaries lumen is much narrower. Wouldn't the narrowness of the blood vessel increase the pressure? Also the ...
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1answer
58 views

Red Blood Cell Size Vs White Blood Cell Size

I have just found out that white blood cells are larger than red blood cells and now I'm confused due to something I learnt in class. Basically, I was taught that there were spaces between the ...
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Blood Vessels (Artery Vs Arterioles)

I just have a quick question regarding what my textbook says. I have tried searching online but I have failed to find an answer. Basically, my textbook states that arterioles are smaller in diameter ...
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297 views

Cutting off circulation [closed]

How much force is required to cut off the blood circulation of, lets say the average human arm? I'm asking because i'm bored and want to try it on myself. I know that in just a couple of seconds with ...
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why is erythrocyte sedimentation rate higher in females?

erythocyte sedimentation rate should be independent of the sex. what is the reason behind this sex bias and why does it increase during pregnancy and how does age influence it.
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Flow diversion for cerebral aneurysms or stabilizing the hemodynamics?

I'm doing research of flow diverter for cerebral aneurysms applications and I'm wondering the reason behind stent placement underneath of cerebral aneurysms is to divert the flow or stabilize the ...
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147 views

How does vasoconstriction retain heat?

I am reading on vasoconstriction on wikipedia. The article states that: When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular ...
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1answer
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Is a large tumor is more likely to develop hypoxic regions?

It is known that cancerous tumors in humans can develop hypoxic regions where no blood nor oxygen arrive to some volume of its cells, creating a dead lump inside or around the tumor. See Wikipedia - ...
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Are there macrophages in the blood vessels and within the blood stream?

Monocytes are phagocytes that "evolve" or "differentiate" into macrophages. I read that there are monocytes in the blood stream and vessels and that macrophages are found mainly in other tissues and ...
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“Blood circulation”. Why blood bleeds in atmosphere ?

If our body's blood pressure is 120 mm-Hg then why blood goes out of our body in 760 mm -Hg pressure if we have cuts?
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Turbulence in blood

Turbulence in blood flow is known to indicate diseased or obstructed arteries. Techniques to measure turbulence in blood flow are mostly based on turbulence kinetic energy measurments using MRI [e.g., ...
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Where does the human brain drain to?

When a brain has a aneurysm and the patient survives untreated then where does that blood drain to or how is it absorbed? How is the pain perceived?
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How does blood react to heat when inside the body

I was wondering: What are the possible dangers of being burned on the surface of the skin. Does it congeal (that's what my intuition tells me)? At which temperature would that happen? How heat-...
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How much blood flows to female breasts?

How much of the entire blood in the body blood flows to the breast (while resting). If you know the percentage or absolute values , as well as the total cardiac output, I would appreciate it answers ...
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Why isn’t Haemoglobin a plasma protein, rather than being encompassed by the erythrocyte?

Erythrocytes (red blood cells) are a common feature of almost all vertebrates. What evolutionary advantage do they provide in containing haemoglobin, rather than it being just a plasma protein? In ...
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Why do we feel numbness and an electric sensation in our legs after standing for too long?

We have all felt that numbness while standing immobile for a while.It gets difficult to walk.It can also happen if we are just putting some pressure on our legs Why does this happen? I'd like to ...
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32 views

Using formulas to explain why contraction of blood vessels leads to increased blood pressure

I know, I know this is probably a question too simple to be asked on a forum like biology stack exchange. Problem is, I looked many places and can't seem to find a more mathematical approach to ...
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How much arteries expand during systole?

Arteries expand during systole. By what percentage, on an average, does the arteries' diameter change during systole with respect to diastole? Answer may depend upon type of artery i.e. elastic ...
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Is carbon dioxide dissolved in plasma same as carbonic acid?

Carbon dioxide is transported through blood via 3 methods : 1. Dissolved in plasma 2. As bicarbonate ion 3.through RBCs. The carbondioxide when transported as bicarbonate ion i.e HCO3- and H+. What ...
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Are new blood vessels able to deliver oxygen to hypoxic tissue before the establishment of blood circulation?

Sprouting angiogenesis - the growth of new blood vessels from a preexisting vasculature - can be triggered by cells in hypoxia in order to re-stablish the oxygen and nutrients supply to the tissue. ...
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Does donating blood lower testosterone levels? [closed]

I'm a guy and I decided to donate blood because of persuasion. My testicles feel weak afterwards specifically. I mean they feel like they're compensating -- assuming that makes sense. Is this because ...
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Does the right ventricle affect blood pressure in pulmonary veins?

Now, I know there are multiple things that push the blood through the entire pulmonary circulation like the contraction of arterial muscular walls... But what I want to know is whether the right ...
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How long can one go with necrosis?

In general, when a limb dies, how long does it take before it falls off? Can you go years with a black and useless limb, or does it just.. fall off right away?
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Is a one ventricle heart feasible?

So this is derived from a lesson at Khan Academy. The mind activity assumes that the one ventricle heart pumps blood to the lungs for oxygenation then rest of the body. However, the problem is that ...
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How urination prior to blood test may give error?

Source: Textbook of Practical Physiology, 4th Edition according to it urination within 30 minutes is a precollection factor that may alter the results of blood test. I am unable to comprehend how ...
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Why are bruises not lethal?

Given the following: bruises are caused by minor trauma which breaks blood vessels beneath the skin, causing bleeding the mechanism by which bleeding stops is clotting blood clots inside the body ...
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Why doesn't nitrogen diffuse into blood?

In school, I have learnt that the deoxygenated blood brought in to the Alveoli by Pulmonary Arteries contains Carbon Dioxide. And that Carbon Dioxide present in the blood diffuses into the Alveoli and ...