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0
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0answers
17 views

Why 'blood vessels' and not 'blood tubes'? [migrated]

I have a silly question. The way I imagine arteries and veins are as tubes that arise from one part and carry blood to the other part. Why do we call them 'vessels' (which reminds us of cooking ...
8
votes
2answers
942 views

Are blood vessels organs?

Are blood vessels classified as organs? Organs compose of 2 or more tissues and perform a certain function. Blood vessels have 3 different tissues and perform a function (transport blood), yet I do ...
4
votes
1answer
52 views

Oxygenated hemoglobin in MRI

I have read the following sentence: Because this oxygenated hemoglobin is unaffected by magnetic fields, the response RF signal returned to the fMRI scanner is stronger when there is more ...
1
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1answer
24 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!
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1answer
25 views

Where does the exudate comes from during inflammation?

During inflammation transudate and exudate is formed by vessels. I would like to make sure if it comes from arterioles, venules, or both, and the reason why.
1
vote
1answer
22 views

Difference between pulse and blood pressure

I'm a very naive and biologically illiterate person, and from what I've read on the internet I'm not really sure I understand the difference between pulse and ...
-5
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1answer
79 views

Why do fingers swell during cold winters?

When exercising, tissue in the hands may swell. This may be caused by the muscles generating heat, which leads to blood being pushed to the vessels closest to the surface of your body to dissipate the ...
5
votes
1answer
107 views

How does the brain cool itself?

Thoughout life everyone tells you that brain is essentially a computer but just like computers your brain would create immense amounts of heat by being in use, so if that's the case how does it cool ...
1
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2answers
89 views

How does the body respond to blood donation; are there any possible risks?

Can blood donation cause any harm to the donor? I have been told so, but cannot find any references supporting this claim. I have also learned that our body will replace the lost fluids within 24 ...
6
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5answers
112 views

Is the amount of blood that flows through every vein and artery per minute really a constant?

I was listening lectures from Mark Saltzman via Open Yale Courses. Now, if I did not understand him wrong, he said that the amount of blood that travels through every vein and artery in our bodies per ...
3
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0answers
46 views

Human leukocytes (re)circulation/migration in homeostatic state

One can easily find information on the topic of leukocytes trafficking between vessels and peripheral tissues during inflammation. But what happens during normal states when there is no pathology? ...
3
votes
1answer
56 views

How does Hemocytoblast constantly get formed into so many blood cells and yet remains there in the bone marrow throughout the lifetime?

I mean, Hemocytoblast is a stem cell which is constantly being differentiated into daughter cells and leads to formation of all the blood cells (having short and limited life spans), so how come those ...
1
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0answers
14 views

How does so many replicas of different kinds of blood corpuscles form from different cells in the bone marrow? [closed]

I am interested in the process by which so many identical blood corpuscles form from an entirely different cell (within the bone marrow) altogether. How does these cells form?
7
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1answer
115 views

What creates the feeling of 'excess' blood pressure to an area of the body?

If I hang upside down, and feel blood rushing to my head, what structures are actually responsible for me "feeling" this excess flow of blood? Baroreceptors? Mechanoreceptors? Something else? ...
3
votes
1answer
74 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 ...
2
votes
2answers
350 views

Blood circulation - How to expand blood capillaries?

Do blood capillaries expand? If yes, through what means can it be done? And can warm water also be used to expand blood capillaries?
26
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3answers
5k views

Why draw blood from veins rather than arteries?

Why draw blood from veins rather than arteries? Is it more convenient or safer?
5
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2answers
132 views

How long can the brain survive during ongoing cardiac arrest?

There was this interesting discussion on CPR and defib in response to the question "Why can't we defibrillate the heart within 1 minute after ventricular fibrillation by electroshock?". Now I was ...
0
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0answers
49 views

Is the molecule nitric oxide responsible for healing blood vessels?

Is the molecule nitric oxide responsible for healing blood vessels? How does nitric oxide heal the blood vessels? I watched a documentary about the healing effects of nitric oxide. In the video I ...
2
votes
1answer
85 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 ...
23
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1answer
3k views

How many mosquitoes would it take to “drain” enough blood to put a person into shock?

I'm just curious, how many mosquito "bites" (mosquitoes which have removed blood from a person) would it take to remove enough blood to put a person into shock? (Putting aside all reasons why it ...
3
votes
1answer
163 views

Why can blood group O be given to all blood groups?

Blood group O has antibodies against antigens A and B. Blood group A has A antigen. If someone with blood group A receives donor blood with group O, then anti-A antibodies in the donor blood should ...
6
votes
1answer
80 views

Blood cells penetration

Is there a type of blood cell that can reach all other body cells? By "reach", I mean to "touch" the surface of the target cell. If we look at the red blood cell for example, that moves in blood ...
8
votes
2answers
197 views

Why don't we see turbulence in the aorta even in normal situations?

I read about the Windkessel effect. Then I read about pulse pressure waves getting reflected from the periphery. If the pulse pressure wave is reflected during diastole and at the same time blood is ...
0
votes
1answer
172 views

What is the difference between the basal membrane and the basal lamina?

I'm researching about the basal lamina in lung tissue and I'm not sure if the basal membrane is the same. What is the difference between them?
1
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1answer
334 views

What are the risks of elevating the legs too regularly and when tired?

I started to to think the pathophysiology of elevating legs high next to the wall too often and when you are tired. I think possible manifestations some damage to valves of the veins (No!) because ...
4
votes
2answers
1k views

What happens when you mix type A with type B blood (and v.v)

What happens when you mix different blood types that are not compatible? For example, if a patient has type A blood and receives type B blood, or v.v.?
3
votes
0answers
105 views

Which types of blood vessels can regenerate in humans/mammals?

Which types of blood vessels can regenerate in humans/mammals? From what I understand, arteries and arterioles can be created later in life, while this is not necessarily the case with veins. However ...
3
votes
0answers
61 views

Relationship between mN and mg in vessel contraction studies?

What is the relationship between mN and mg as the units involved to measure the changes in contraction? A tool most widely used is an instrument called myograph. In these exoeriments, either units of ...
7
votes
3answers
351 views

Where does extra blood come from to fill your muscles during exercise?

Let's say I go to the gym and lift some weights an hour. During this time my arms will grow due to the "pump" -- the extra blood rushing in to feed the muscles. For example, I've measured about 2-3 ...
3
votes
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 ...
4
votes
1answer
816 views

Why do veins look blue?

I know that veins carry oxygen. Veins look blue because the oxygen-depleted blood in them is blue. Is this true??
1
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1answer
448 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, ...
2
votes
1answer
71 views

Speed of effective lymphatic drainage?

Lymphatic drainage occurs from many portions of the body: To venous angle: head axillary lymph nodes hands abdomen legs (I think legs' drainage goes through abdomen) The speed of the lymph ...
0
votes
1answer
35 views

Manifestations of open foramen ovale in adults

I read that foramen ovale opens in 30% of adults. I do not know how much of these openings can then close again. Probably, none. It is not pathogenic if no symptoms. It allows blood to enter from ...
2
votes
1answer
889 views

How do nutrients get to the cells they need to get to?

I understand the basics of digestion. I know that nutrients get absorbed by the microvilli, enter the bloodstream and travel to the liver but after all that, what is the biological mechanism that ...
1
vote
1answer
77 views

People say the cardiac cycle depends on blood pressure? How so?

I know what the cardiac cycle is. There are two phases diastole and systole. One is the relaxed, and the other is the contracted form of the heart. The diastole is where blood is pumped to the ...
7
votes
1answer
231 views

What causes Paresthesia (Pins and Needles) at a cellular level?

I've looked it up in plenty of places like the Wikipedia page and such, and it is clear that the most common cause of Paresthesia is either a fair amount of pressure on a specific patch of skin ...
0
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0answers
24 views

How does vasomotor and bronchomotor reactions equilibrate local blood flow to correspond local ventilation?

I am trying to find some figure(s) to explain this. There is probably better name for "bronchomotor" reaction. They seem to opposite terms and actually affecting same things (alveolar diameter/tone); ...
1
vote
1answer
166 views

What is the blood ejection speed outward from human body vein? [closed]

At what height blood can eject from human vein ? I see, sometime there is direct blood transfer from one person to patient. So sometime blood bottle is kept at certain height and blood is transfered ...
0
votes
1answer
51 views

Pathogenesis of chronic venous congestion in skin?

I think CVC cannot lead to heart failure primarily. So let's think its pathogenesis in skin now only. I think the pathogenesis is like this dilation of veins and capillaries due to impaired venous ...
3
votes
4answers
77 views

Can systemic intravascular thrombosis cause brain infarction?

I wonder if the thrombus can pass through the brain-blood barrier because I think small molecules like O2, CO2 and ethanol can pass it. Probably, in some diseases where the permeability of the barrier ...
-2
votes
1answer
50 views

Which chemical and hormonal effects on heart are by metabolites? [closed]

I am thinking which hormonal and chemical effects from: catecholamines thyroxin corticosteroids sex hormones prostaglandins Ca2+ Na+ K+ can be be regarded as metabolites i.e. intermediates or ...
0
votes
1answer
23 views

To characterise diameter of capillaries in organs

I know that there exist Continuous capillaries (skeletal muscle, adipose tissue, connective tissue, pulmonary circulation), Fenestrated capillaries (small intestine, renal glomerulus, exocrine ...
0
votes
1answer
42 views

What is the quality rate of intrinsic autoregulation in the heart?

Autoregulation is the maintenance of constant blood flow to an organ in spite of fluctuations in Blood pressure. It involves the relaxation of myocardium and contraction. It is local. I know that ...
1
vote
1answer
32 views

What are the movement mechanisms of thrombus?

I am thinking how thrombus (veins, arteries and heart) can move. Secondary mechanisms come to my mind only: some enzyme which lyses it, probably adhesion mechanism. Blood circulation (flow rate) ...
1
vote
0answers
66 views

To define the total Resistance of Systemic Blood Circulation

Some systems are in parallel. For instance, the resistance of lungs $R_{\text{lungs}}$. Assume here for simplicity that these parallel systems can be handled linearly. We also consider only Total ...
0
votes
1answer
183 views

How does human body deal with inert solid material in the bloodstream?

How does human body deal with inert solid material in the bloodstream? For example, if there is a powder of glass injected into our bloodstream, will the white blood cells do anything or will kidney ...
2
votes
1answer
80 views

What happens during a Raynauds episode?

Raynaud's phenomenon can be a serious health issue, as the blood flow to the extremities, mainly the fingers is compromised, causing fingers to blanche, and then turn blue. Severe Raynaud's can cause ...
6
votes
3answers
167 views

Why are diabetic people often overweight?

I was looking at diabetes the other day, and I noticed something strange. Lower amounts of lipase are a symptom of diabetes, as is overweightness. However, since lipase is the enzyme that breaks down ...