The study of the normal function of living organisms and the means by which it is achieved.

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How does a blunt force stimulate histamine to develop early stages of inflammation?

I know that viruses and sharp forces can stimulate mast cells by cut or by a virus infecting them and then release histamine. How can blunt force do this and cause inflammation? It doesn't have the ...
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1answer
59 views

Do insomniacs yawn?

According to wikipedia, the jury is still out on the function a yawn serves. The article referenced above however writes to say Yawning most often occurs in adults immediately before and after ...
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30 views

What is the nature of action potentials in autonomic nervous system?

My conjuncture is that the natures of sympathetic and parasympathetic action potentials are different. My findings propose me that sympathetic action potential is little longer lasting than ...
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538 views

Crusty eyes in the morning

Often, after waking up from a night's sleep hard, flaky, pale yellow crystals are deposited around the eyelids (which easily wash off with water). What are these? Why are they yellow? What are they ...
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32 views

Does Sympaticus and lymphatic circulation cause feeling of thirsty after short shower?

I have been reading blogs, Guyton and Pocock about what triggers the feeling of thirsty. I am not convinced that is the fact of warm water time is short so not much water lost Assume that the ...
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47 views

Advantage of cup-like shape of blood cells, spores?

Mold spores sometimes have the same shape as platelets in blood. If I were designing a spore it would probably be spherical. Is there any advantage to this cup-like shape? Maybe there is some ...
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64 views

How does regurgitated food go to the 3rd stomach chamber instead of going to the 1st?

Ruminants are known for their regurgitation of food; the food goes through the 1st and 2nd stomach chambers, then returns to the oral cavity in cuds. The cuds then come back into the stomach, but this ...
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26 views

Are there naturally occurring Biological Pacemakers?

There are artificial biological pacemakers which express funny channels. I am thinking if it is possible to have also naturally occurring (only in recovery cases and in silent tissues) biological ...
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10 views

Mechanisms to start simultaneous depolarisation of two Pacemakers?

I am thinking the biochemical mechanisms of the simultaneous depolarisations of two pacemakers. My intuition Funny channels (but not alone) No autonomic nervous system (my conjencture) What are ...
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1answer
41 views

Earwax versus Mucus

Something I have wondered for a while is why have two different primary defense mediums, ie earwax and mucus, that perform the same function? As far as I know, mucus and earwax are both part of the ...
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11 views

What are the mechanisms of disabling extrinsic control of heart?

I started this thread by thinking this question but I developed it further below What is the mechanism maintaining refractory period of pacemakers? My conjuncture is that the mechanism is the ...
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132 views

Is it possible to have life in vacuum?

I just got struck by curiosity now: Intuition says no, but I've never had confirmation of it.
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21 views

Which reflex arcs work in Heart with extrasystoles?

I am researching what is triggering the extrasystoles - initial idea from this thread about Which ionic channels of Pacemakers can work in very low frequencies in extrasystole? I am interested in the ...
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14 views

Which ionic channels of Pacemakers can work in very low frequencies in extrasystole?

At frequency 0-3 Hz. Like computer processors which can work at low frequencies and controlling under- and overvoltage. Normal most significant channels are Ca2+ and K+ that are changing. However, I ...
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89 views

Task-dependent “reversed” handedness: why use left hand for some tasks? How is it controlled by the brain?

I am right-handed. Which means that when I hammer down a nail, I hold the nail in my left hand, with which I can hold it straight and at a controlled position. This is true in situations where the ...
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14 views

Calling for Pressure pictures about Right and Left atrium

I am trying to understand the partially patent foramen ovale in patients with right-side heart failure. I am interested how the pressure in right and left atrium change in normal case in abnormal ...
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2answers
39 views

Is Sinus node conduction necessary for heart beating?

Assume a patient with previous cardial infaction which SA node not possible to activate action potential anymore. However, SA trying to beat unsuccessfully repeatedly waisting energy. Therefore, I ...
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20 views

Laser surgery to stop damaged Sinus node from beating

I am trying to find any publication about laser surgery to stop the damaged sinus node which cannot anymore beat. I could only find publications which modifies SA node function. I am not sure if it ...
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1answer
83 views

Why mosquito bite is confined to a certain shape?

I think this problem should be asked in a physiology forum rather than biology@ stackex but I'll give it a try. So my question is simple - why a mosquito bite is usually confined to a certain shape ...
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1answer
63 views

Do people with gout live longer?

Antioxidants reduce damage to tissue (by scavenging the free radicals) and thus may reduce ageing.It is known that Uric acid is a very good antioxidant. People with gout have excess accumulation of ...
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4answers
282 views

Do tall people have more cells?

Within a single species, how does the relative number of cells in the body relate to the relative size of the organism? Let's say we take two humans, one of them is 6 feet tall and the other one is 5 ...
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28 views

Normal Frequencies in Heart

I am trying to visualise possible ranges of frequencies from different structures of heart: different valves and their possible frequencies heart sounds I - IV and their normal frequencties what can ...
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31 views

How do the symptoms of Sepsis affect heart function?

I have intuition that Sepsis with infection can cause spastic functioning of heart during systole heart working spontaneously in snatches during systole atrial fibrillation first contraction of ...
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1answer
42 views

Nervous system: Pain and Pleasure?

If you have a constant pain in your body, why does a greater pain or pleasure make you not feel the original pain?
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48 views

Missing 4$H_2O$s (per glucose) in Cellular Respiration… Where can they be?

I having trouble understanding the equation of the cellular respiration. The thing that bothers me is the number of $H_2O$ molecules. Generally, cellular respiration is written thus : $C_6H_{12}O_6 + ...
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1answer
28 views

Fibrinous inflammation, exudate and scarring in monotonous movements and ageing

I have palpated many hard organs during my work and studies. I have seen many young and old people who have hard organs, like very hard shoulder - very common. I have interviewed some of them, some ...
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63 views

A day in Beijing is like smoking Only one sixth of a cigarette

This is the title of this blog post followed by this other good post. I'm particularly anti-tobacco-smoke, at the point of not always considering other pollution, and this article shows how this kind ...
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107 views

Are females more flexible than males in all mammals?

It's common that human females have a more flexible body than males, (but I don't know why, so it'd be helpful if someone answers why so as well!) but does this apply to all mammals?
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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); ...
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1answer
37 views

What is the function of clot retraction?

I am thinking how clot retraction and fibrinolysis work together. I think that clot retraction is a process that gets clot towards fibrinolysis process. Fibrinolysis process then lyses the clot. ...
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1answer
16 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 ...
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1answer
22 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 ...
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1answer
24 views

Are there any forms of heart failure where cell size decreases?

I think hypertrophy happens in most of the cases. However, I am not sure if hypertrophy always happens. I started to think about wet lungs (pulmonary reason for the left-sided heart failure). Can the ...
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1answer
43 views

What is ischaemia exactly?

I think it is decreased blood supply to organs and tissues. I also think it is the stopped circulation. However, both ones cannot be right, I think. What is ischaemia exactly?
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47 views

What is the difference between intracardiac and extracardiac reflexes in cardiac regulation?

The primary parameters of heart pumping are strength of contractility (inotropic positive; Frank-Starling relationship) rate of relaxation (lusitropic positive) heart rate (chronotropic positive) ...
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1answer
45 views

Do's and Don't's of Undergraduate Research? [closed]

I was fortunate enough to get a position as a researcher for the Mayo Clinic's SURF Program this year. My PI's lab focus is on the the immune system's role in CNS axonal and neuronal injury, ...
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2answers
119 views

Electronic cigarettes (e-cigs), any health risks?

Background: An electronic cigarette (e-cig or e-cigarette) is a battery-powered device which simulates tobacco smoking patented in 1963 by Herbert A. Gilbert. It generally uses a heating element ...
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1answer
39 views

What are the physiological roles of Hydrogen sulfide?

I am thinking why hydrogen sulfide has its effects in the body. For instance, it is one Salmonella's virulence factor. I am not sure if such a balance equations holds ...
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0answers
28 views

Nearly Exhaustive List for Cholesterol Pathways

I have run across an interesting case that is similar to only two others I've encountered. What makes it interesting is the combination of undetectable (under normal testing conditions, can elaborate ...
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1answer
82 views

Can too low oncotic pressure lead to Third spacing and Edema?

I know that low oncotic pressure is associated with many pathologies. I am interested how it is associated with Third spacing. My professor says that it can permit edema formation. The opposing ...
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2answers
89 views

Hypovolemia and orthostatic hypertension

What is the physiological mechanism behind the occurrence of orthostatic hypertension in the presence of hypovolemia?
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1answer
52 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) ...
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1answer
23 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) ...
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1answer
22 views

How many systemic reactions in inflammation?

I have this sentence in my notes Inflammation consists of two local reactions and one systemic reactions. which is difficult for me to accept. Two local reactions are vascular and cellular. I ...
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2answers
54 views

Why do humans circulate monosaccharides instead of disaccharides as in plants?

Plants transport food mostly in the form of disaccharides like sucrose but humans transport them in the form of a monosaccharide - glucose. What is the reason behind this ?
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3answers
234 views

Why do we exhale after we hold our breath?

I tested this out with my friends, and I find that after they hold their breath and can't hold it anymore, they exhale air, instead of inhaling air. Interestingly, they all try to inhale in as much ...
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2answers
117 views

Why there is a very high drop in pressure from arteries to arterioles?

Laplace law explains why the pressure is the same in aorta and arteries (100). I am thinking why there is so big drop in pressure when going from arteries to arterioles (40-60). Why there is a great ...
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2answers
304 views

Converting unit/mg or unit/ml into ng/ml, or vice-versa

I am working with the enzyme Cu/Zn Superoxide (SOD1) and i am quantifying them in ng/ml. However, most past studies has SOD1 quantified in unit/mg or unit/ml, and i need to compare the SOD1 level of ...
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1answer
34 views

Late control mechanisms of blood pressure (arterial) level?

I first covered the fast and moderate control mechanisms which I think are Fast control: Baroreceptive reflex (tonus), Chemoreceptive reflex (CO$_2$). Moderate control: Bicarbonate (ECF), ...
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37 views

Effect of respiration on Arterial pressure

I am trying to explain the effect of respiration on arterial pressure. I am looking preferably some visual way to show it. How can you show the effect of respiration on arterial pressure? I am ...