Biology Stack Exchange
Biology Stack Exchange

Questions tagged [physiology]

The study of the normal function of living organisms and their anatomical parts and the means by which their normal functioning is achieved.

Physiology is the study of how organisms, organs, cells, and biomolecules carry out the chemical or physical functions that exist in living systems. It can be subdivided into human, animal, plant, bacterial, etc. physiology. Questions should be about function, while the tag should be used for structure questions.

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How are long time periods measured in biological systems?

Biological systems are pretty good at measuring fairly long times, for example, menstrual cycles (month), or puberty (years). Counting days or years seems to be implausible, and chemical concentration also seems implausible. What are the…
Memming
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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 feet tall. They have similar BMI, age, physical…
Superbest
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Dimensionless number for blood volume

Comments from the question How is the blood volume of a living organism measured without killing it? by @Nico discussed that the time of blood recirculation scales with the size of the organism. I was curious if there were a series of dimensionless…
bobthejoe
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What really happens when a body is tired?

This may be anecdotal; please feel free to vote to close. After staying awake for an extended duration, I usually find myself having to take extra effort to focus my eyes on an object. Similarly after exerting myself to the extent of near total…
Everyone
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What is the top speed of muscle contraction?

Currently I am looking into what muscles groups are most used during a football kick. I have a hypothesis that the quadriceps are not as used as most people think because the momentum the swing creates makes the knee extend to fast for the…
Atom Scott
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Would my hands sweat this much if I wasn't wearing gloves?

I've wondered about this for a long time, and hopefully someone here has a reasonable answer. I'm a cell and molecular biologist, and much of my time at the bench is spent wearing (usually nitrile) gloves. I've noticed that if I wear them for longer…
MattDMo
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What causes the characteristic 'gleam' in the eye of a living being?

The title is pretty much what I seek to know. Unless the other person is play-acting, one can often make out the eye of a living person has a shine-of-life to it; a cadaver does not. Similarly the gleam appears brighter when a person is feverish, or…
Everyone
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How is hibernation/aestivation different from anesthesia?

How do hibernation/aestivation happen? I read on wikipedia that a squirrel injected with the body fluids of a hibernating fellow is more prone to hibernation. If hibernation/aestivation are driven by biochemicals and not merely the weather, can the…
Everyone
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How deep does water have to be so a mosquito can lay viable eggs in it?

I read about this idea for a mosquito trap (with a rather tactless name) where the idea seems to be that because the water available for the mosquito eggs is so shallow, they will die somehow or not be viable. Mosquitos are pretty small though,…
tM --
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What type of force holds my body rigid & doesn't make it collapse?

My query is that as atoms & its molecules have inter & intra molecular forces,like that only what type of force keeps the cells bonded to each other & prevent it from collapsing ever since.
Manik
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Is the empty GI tract a hollow tube with air inside, or is it generally collapsed until food is eaten?

I have heard that "air in the GI tract" results in flatulence and burping etc, however I initially assumed that the "empty" GI tract was a hollow tube filled with air anyway. So on an empty stomach (or "empty" GI tract rather), does the GI tract…
Kenshin
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How does extracellular potassium ion concentration and calcium ion concentration affect the excitability of a cell?

When extracellular $K^+$ concentration increase by a certain amount, excitability of cells is higher because the resting potential shifts toward a higher equilibrium potential of $K^+$, therefore causing depolarization. However, when there…
Lisha
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Do animals only breathe through one nostril at a time like humans?

Humans breathe through one nostril at a time. Do non-human animals also do so, or do they breathe through both nostrils at once? Has any actual study been conducted on this topic?
Ajit S Gokhale
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What keeps organs suspended in the body?

I'm a bit confused what prevents our organs from not collapsing into a heap or putting pressure on each other. I have a 3D anatomy app and have been studying the relationship between the organs. According to the models, the organs are remarkably…
Stan Shunpike
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What causes instinctive behaviour?

Some actions, almost behaviour, exist that are common across a species. For instance, based on personal observation, human babies try to taste anything new they encounter until they are a few score months old. Similarly most dogs will go…
Everyone
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