The study of the normal function of living organisms and the means by which it is achieved.
1
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1answer
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?
1
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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 ...
0
votes
0answers
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 ...
1
vote
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?
0
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0answers
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, ...
2
votes
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 ...
0
votes
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
votes
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
votes
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 ...
0
votes
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, ...
0
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0answers
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?
0
votes
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
votes
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 ...
0
votes
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?...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
1
vote
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 ...
-1
votes
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
votes
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
votes
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 ...
0
votes
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 ...
0
votes
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
votes
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 ...
0
votes
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 ...
4
votes
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 ...
1
vote
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 ...
0
votes
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?
3
votes
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?
0
votes
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 ...
0
votes
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 ...
-1
votes
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
votes
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 ...
0
votes
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
votes
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 ...
0
votes
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
0
votes
0answers
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 ...
3
votes
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?
1
vote
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 ...
0
votes
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.
...
1
vote
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 ...
5
votes
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.
...
0
votes
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 ...
0
votes
0answers
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 ...
1
vote
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 ...
1
vote
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 ...
1
vote
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
votes
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 ...
0
votes
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 ...
1
vote
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 ...
