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

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12 views

Can neurons take oxygen from air?

Why can't/don't neurons take up atmospheric oxygen, or dissolved oxygen (like amoeba does) to sustain their life processes?
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1answer
36 views

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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24 views

Is genetic imaging usually considered as physiological measurement?

I think that since genetic determine the physiology of a person, it should be considered as a physiological measure. But what is the convention in academia? (i.e. if someone want to talk about ...
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1answer
28 views

Common english name for tissues which are separated from the blood by blood-tissue barriers

Which general term is used to denote such organs/tissues as: brain, testis, thymus etc., which are separated from the blood by blood-tissue barriers?
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17 views

How the albumin regulates osmotic pressure

Do I understand correctly that: When albumin binds non-water molecules to itself, the concentration of non-water molecules decreases, thus the osmotic pressure decreases; When albumin carries water, ...
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2answers
57 views

how can mitochondrial proton leak make heat?

I read something about thermogenin. It said "When thermogenin is inserted into the inner mitochondrial membrane, it accentuates mitochondrial proton leak and dissipates the proton motive ...
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0answers
10 views

Proteins passimg through oocyte membrane

It is alleged that a females previous mating partners can affect future offspring through male accessory gland proteins. However I dont see how this is possible if the smallest proteins are typically ...
4
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1answer
68 views

What physiological processes give rise to a linear cell survival curve?

If we plot the number of surviving cells in a structure over time (assuming no replacement), the shape of that curve should imply something about the underlying process responsible for cell death. For ...
2
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2answers
32 views

Cross-species infections

I’ve heard that HIV developed from SIV, etc. I’ve also heard that most species (including most monkeys) can’t get a common cold like humans. So then what causes infections to be able to travel ...
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1answer
27 views

What is (are) the medium of conduction for an electrical current with an external source in the human body?

I am trying to get some background for some personal research I am doing into the effects of Electro Convulsive Therapy. I don't understand how electric current from an external household source, say, ...
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7 views

Valves of heart

Do adult heart have thebasian valve or it is merged into musculature? How does blood is controlled in absence or presence of it?
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0answers
9 views

The graph of osmosis: Artificial Osmometer

Is the slope of osmosis linear or non-linear? In terms of the time and the distance traveled in an osmometer.
3
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1answer
84 views

Why do crocodiles have a high concentration of lactic acid in their blood?

Crocodilians have high concentration of lactic acid in their blood. This is the cause that prevents them from prolonged intense activity, since prolonged intense activity causes the muscles to secrete ...
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0answers
44 views

Interstitial volume

In the literature, studies mention that the interstitial space surrounding cells varies in each tissue. Are there references from which one can obtain the values of interstitial volume in each tissue?...
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0answers
7 views

Wound Healing Speed Across Soft Tissues?

I've heard that different tissues heal at different rates. Does anyone know of any attempts to measure and quantify the rates of soft tissue healing across different tissue types, or to determine the ...
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0answers
32 views

Acute calculous cholecystitis

The action of mucosal phospholipases hydrolyzes luminal lecithins to toxic lysolecithins. The normally protective glycoprotein mucus layer is disrupted, exposing the mucosal epithelium to the direct ...
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0answers
21 views

Hematuria due to Nitric Oxide

Drug interactions between properly dosed NO and other medications are not expected, but side effects may include noisy breathing, hematuria, or possibly atelectasis. (pg.no:577; Goodman and Gilman ...
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0answers
35 views

about the muscle's tension's variables

I'm reading the paper "THE PROBLEM OF THE INTERRELATION OF CO-ORDINATION AND LOCALIZATION", which is written by N. Bernstein. The paper said "The degree of tension of a muscle is a function, in the ...
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0answers
12 views

Why is serum ferritin elevated in Chronic disease anemia?

I've been searching the reason of this but I've been not able to find it.
2
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1answer
41 views

Is every neurotransmitter receptor an ion channel?

This is a rudimentary question--perhaps the answer is well known to biologists, but is every neurotransmitter receptor also an ion channel? For example, NMDAR is a glutamate receptor and cation ...
2
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1answer
87 views

Are we evolving as fast as the oxygen is depleting?

How much oxygen saturation have we lost in the last 100 years? As oxygen levels dwindle and industry, deforestation, and population increases, at what year and saturation will the low levels of ...
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0answers
49 views

Why do people have characteristic body odour?

I am informed that odour (specifically coming from armpits) is due to bacteria residing on the skin do the work of manufacturing the malodorous compounds. So why do people have characteristic body ...
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2answers
53 views

How does 2,3 biphosphoglycerate works to release oxygen bound to the hemoglobin?

I read on Wikipedia that 2,3 BPG binds with the deoxygenated state of hemoglobin and helps in stabilizing it. It was also written that it helps release remaining oxygen from the hemoglobin. How? ...
2
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1answer
169 views

Mechanism by which hypokalemia reduces insulin secretion

Is there any known mechanism by which hypokalemia reduces insulin secretion? This video explains a mechanism, but its inherently wrong because ATP dependent K+ channels will allow movement of K+ from ...
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0answers
14 views

CETP inhibitors and LDL levels

While CETP inhibitors effectively reduce LDL, they also paradoxically increase the frequency of adverse cardiovascular events (angina, revascularization, myocardial infarction, heart failure, and ...
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0answers
46 views

Is there a biological determinant for right- or left-handedness?

When I was very young, I was sent by parents to examination where I was told both my hands are dominant in the same way. My parents preferred to make my life easier and chose to focus on my right hand ...
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1answer
87 views

Why does applying pressure to a venipuncture site prevent haematoma?

From what understand, when drawing blood, a phlebotomist puts pressure on the venipuncture site while withdrawing the needle to prevent a haematoma. I'd like clarification; How does this prevent a ...
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0answers
41 views

Boron vs Costanzo for first year of medical school?

Which book for physiology out of Costanzo and Walter Boron would you recommend to a first year medical student who has read upto the level of Campbell’s Biology textbook in high school?
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1answer
85 views

Are all mammals capable of sneezing?

I only know dogs and humans sneeze... so do other mammals sneeze as well? Is it possibly an evolutionarily-determined immunological trigger?
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1answer
66 views

How increased potassium intake increases sodium excretion?

"K+ antagonises the biological effects of Na+". I have been reading the same many times without any explanation. How actually (mechanism) K+ helps excretion of Na+?, their interactions? And eventually ...
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1answer
39 views

Does estrogen increase muscular growth in females?

Regarding humans it is said that most psychological effects caused in men by testosterone are caused in women by estrogens. There are many studies on that, particularly regarding temporary shifts of ...
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1answer
27 views

Square-cubed law and health

Does the square-cubed law lead to possible health detriments for taller people? I'm not sure what the optimum height is for humans (e.g. due to their cross-sectional bone density constraints), but ...
2
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0answers
88 views

What do Caucasians see in their peripheral vision, and how is their visual field?

I am an Asian who has no idea how much of their nose Caucasians (especially for those with extremely deep-set eyes, very prominent and low brow ridges, and high noses like Brian Shimansky or Rishi ...
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1answer
24 views

Are “Rings” in fish like rings in a tree? [closed]

A lot of fish have structures like the rings in a tree. Is the number of “rings” an indicator of age, as in a tree, or is it fixed?
42
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2answers
18k views

Why can't we kill ourselves by holding our breath?

Is it possible to kill yourself by holding your breath? This question is obviously copied from Quora, but I had heard it as a fact that we cannot kill ourselves by holding our breath and I'm looking ...
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0answers
20 views

Why the direction of depolarization wave of AV node spread at one way?

I know that there is a refractory period after depolarization but when the ventricles depolarize the atrium gets repolarize then why this wave don't come back from the AV node to the atrium
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66 views

The role of calcium concentration in excitation-contraction coupling of skeletal vs cardiac muscle

Below is an illustration showing the intracellular concentrations of calcium ions during skeletal and cardial muscle contraction; and how they change over time. I understand why the shape of the ...
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2answers
63 views

Phospholipid membrane fluidity if phospholipid had one type of fatty acid

How would membrane fluidity change if the phospholipid membrane had only one fatty acid?
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1answer
508 views

Ventricular Filling : Systole or Diastole?

As the Blood goes down from the Atrium to the Ventricles: The Tricuspid Valve ( Right Atrioventricular Valve) Bicuspid Valve (Mitral Valve ) The atrial pressure is INCREASES WHEN ATRIA ( THE ATRIA ...
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0answers
19 views

Can humans derive any nutrition from eating the bones of animals?

Bones contain many nutrients like Calcium and phosphorus. And I'd take a guess that some kind of bones like bones of a chicken(hollow) aren't dense enough to be much of a problem during digestion. ...
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0answers
38 views

What does it mean for sodium and water reabsorption to be “coupled” in the nephron?

If sodium is transported across the tubule membrane down the concentration gradient established via the $Na^+$/$K^+$ exchanger via symport with glucose and antiport with hydrogen, and water is ...
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0answers
66 views

Do brain consume more energy when stressed or Anxious

When a person is anxious or stressed or suffering from chronic depression, it is observed that the person is usually tired. Is there there a connection between fatigue and racing thoughts/obsessions. ...
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0answers
117 views

What secretes the pericardial fluid that protects the heart from the contraction's friction?

As you guys know, the membrane that protect the heart is the pericardium, which consists of 1) The serous pericardium, which is divided into visceral pericardium and parietal pericardium, secretes ...
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21 views

Understanding hyper- vs hypokalemia

After searching the web for a while, I found that: Hypokalemia results in a prolonged Q-T wave interval Hyperkalemia results in a peaked T wave and a wide QRS complex Now, I'm trying to understand ...
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0answers
19 views

How to obtain normalised ECG given ECG readings across lead 1, 2, and 3?

I saw this youtube video on ECG readings and cardiac dipole vector locus of the heart across the three leads. Posting screenshots from it: My question is how to obtain the graph (2nd image) from the ...
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0answers
71 views

Why is the Mongolian Horse superior in stamina?

I've heard a lot about the Mongolian Horse over the years, especially that it has more stamina than the Arabian Horse. It's a little smaller/lighter than an Arabian. Apparently the Mongol Horse can ...
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1answer
27 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 ...
8
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1answer
222 views

Why can I raise my left eyebrow independently from the other but not the right?

I've seen the same question on other forums, but have not come across any definitive explanation. The non-cited answers seem to fit into three categories: It is due to greater muscle dexterity on ...
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1answer
34 views

Nonpancreatic digestion of tryglicerides

In an answer about coconut oil I can read the digestion of coconut oil does not involve in the Pancreatic digestive enzyme system In both primary and secondary school I have learned that fat needs ...
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0answers
27 views

sweet receptor's affect on insulin release

So I understand the basics of how the body releases insulin to keep blood glucose levels in check and (loosely) that higher insulin levels can lead to more (or at a faster rate) glucose being stored ...