The study of the normal function of living organisms and the means by which it is achieved.
4
votes
1answer
276 views
Conversion rate of topical Retinol to Retinoic Acid (Tretinoin)?
I'm wondering if someone out there has more information than me. Retinoids have well known metabolic pathways in vivo, and it's usually something like: ...
3
votes
0answers
82 views
what are the mechanics of sweating?
The causes of sweating aside, i.e. I'm not interested in which and how nerve signals are transmitted to sweat glands. But I would like to read a detailed account on what a sweat gland consists of, ...
1
vote
3answers
105 views
What difference does it make in the organism's physiology/metabolism whether oxygen binds reversibly or not?
A follow-up to How does hemoglobin-free blood transport oxygen?
I'm unsure about the use of physiology/metabolism in the title there. The question in mind is whether this reversible binding makes an ...
10
votes
1answer
107 views
Does stress physically age our body?
Going by the assumption that stress eventually triggers a flight/fight response, and the subsequent realization that flight/fight puts the body in a system of readiness to use it's available resources ...
3
votes
1answer
232 views
Slow-oxidative fibres vs fast-glycotic fibres
Why do slow oxidative muscle fibres contain more mitochondria compared to fast-glycolytic muscle fibres?
6
votes
1answer
172 views
Can I estimate leaf temperature from air temperature? What other information would be required?
Physiological measurements such as respiration rate and assimilation rate depend on temperature.
Most papers report tissue temperature (e.g. leaf temperature for leaf measurements), although some ...
5
votes
1answer
149 views
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 ...
4
votes
1answer
86 views
What protocol does the nervous system use?
I just read How does an inhibitory synapse communicate to the cell body of a neuron? and found myself asking this question ... hopefully I'm not asking the same thing
Any body possessed of a nervous ...
6
votes
3answers
101 views
What gaseous substances do humans emit?
Other than CO2 and Methane what other gases do humans produce or emit?
For example, does skin decomposition, or aerobic respiration emit any special gases that people don't normally realize or know ...
3
votes
0answers
32 views
Patch-Clamping Neurons Resources
Are there any lectures available on Patch-Clamping?
Were can I find a mathematical model of Patch-Clamp? (that can be easily implemented in matlab).
I have found some step-by-step protocols on ...
9
votes
1answer
291 views
Is trembling an advantageous response during periods of anxiety?
I originally had planned to ask about whether there was any biological truth in the popular phrase "shivering with fright". However, after doing a fair bit of googling it seems that there is a lot ...
9
votes
1answer
129 views
Does the oxygen concentration equilibrate between red blood cells in the liver sinusoids?
In the sinusoids of the liver, venous blood from the hepatic portal system mixes with arterial blood from the hepatic arteries.
Do oxygen molecules move between oxygenated RBCs and non-oxygenated ...
4
votes
1answer
98 views
Is a raised baseline between T and QRS normal in any ECG lead?
Here are excerpts from an unknown ECG lead. I find it weird that the "baseline" changes after the T wave and doesn't return until after the following QRS complex. Is that normal/expected for any lead?
...
1
vote
3answers
53 views
Are all healthy animals more likely to defecate near the end of a rest-cycle?
Just what the title states.
It stems from observation & personal experience that a person/dog/cat/monkey is more likely to relieve oneself immediately after it wakes up from the peak-sleep cycle ...
14
votes
3answers
309 views
Are human fetuses more likely to be male?
Question: From a physiological point of view, when sex is determined in a human fetus, is it equally likely to be male or female?
Studies in this area typically measure age at birth, where the data ...
5
votes
1answer
249 views
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 ...
3
votes
2answers
97 views
Why is most tissue cellular?
Most tissue is comprised of cells. Why? It would seem inefficient to have so many individual nucleus, membranes, etc.?
Specifically: Not all tissue is cellular. Much tissue is extracellular matrix. ...
7
votes
1answer
132 views
How can an albatross stay airborne for months?
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes. They range widely in the Southern ...
9
votes
2answers
202 views
Where do the bacteria within the vagina originate from?
I understand that it's feasible the bacteria within the gastrointestinal tract originate from the food we eat and air we breath, but where does this population of microbes originate from?
1
vote
0answers
70 views
Why is membrane potential not zero at equilibrium?
For the squid giant axon, the membrane potential computed by the Goldman equation is -60mV. And the Nernst potentials are (the differences between the K+ and the Na+'s Nernst potential and the ...
23
votes
1answer
374 views
What is itching?
What exactly at the molecular level is itching? What physiological function does itching serve, if any? I cant remember the reference but a PLCb3 null mice lost the itch phenotype, so presumably it is ...
5
votes
1answer
123 views
Do mosquitoes need to pump blood out of the host?
Many species of mosquitoes have bloodsucking females.
When they bite a host, do they need to pump? Or does the sheer blood pressure combined with capillary action suffice to make the blood rush into ...
8
votes
3answers
233 views
What triggers meiosis in gonadal cells?
What specific biochemical processes are involved in inducing meiosis rather than mitosis? Why are gonadal cells the only cells in the human body which do undergo meiosis?
3
votes
2answers
166 views
Is consuming sugar with food as beneficial as consuming glucose (~half of the amount of sugar)?
A few years back I heard at biology class that sugar's molecule consists of half the number of elements of a glucose molecule. So not counting the energy needed to transform two sugar molecules in one ...
2
votes
1answer
46 views
Is vision a vestigial sense for deep ocean species?
Sunlight doesn't penetrate beyond a couple of hundred feet from the surface of the ocean. Species that exist at greater depth probably live in a state of perpetual night; yet from a quick google image ...
4
votes
3answers
161 views
Biological Pathway of Lipid Hypothesis
I've read a lot on both sides of the debate of low carb vs low fat diets trying to make some sense of what is being proposed. The lipid hypothesis runs roughly along the lines that we have lots of ...
4
votes
1answer
118 views
Is there a way for a 19th century scientist to prove that the octopus doesn't revive?
Say a sophiscated scientist in the 19th century noted that applying soy sauce on a dead octopus leads to movement of the legs, as a result of the voltage differences resulting from the salt in the soy ...
4
votes
3answers
84 views
Do dogs have something different about their physiology that allows them to pant without hyperventilating?
I was wondering this as I considered how effective panting would be for humans as a means of cooling.
2
votes
0answers
35 views
Physiological or molecular difference before and after sleep?
I know that the details of the process of sleep aren't entirely known, but have always wondered why I feel rested after sleep.
Biologically, what differences can be directly observed in the human ...
5
votes
0answers
69 views
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 ...
12
votes
2answers
220 views
Is there any reason for the variation in mitochondrial DNA size?
As my textbook An Introduction to Genetic Analysis points out, yeast mitochondrial DNA has approximately 78 kb of genetic data, while the human mitochondrial DNA contains 17 kb. Is there any evolution ...
2
votes
1answer
399 views
What is the “lifecycle” of an average eschar and what types of cells are involved in each stage?
(after some deliberation in the comments, I've decided to make the question more general)
An eschar or "dry scab" often forms at a site of injury over a large cut or sore.
It seems as though the ...
3
votes
1answer
44 views
Is there such thing as “biological cycles” of activity/performance/etc in mammals?
I'm looking for some information about the cycles of increased/decreased activity, mental performance or endurance that are related to a mammal's age and the time of a season.
First of all, I'm not ...
2
votes
0answers
41 views
Are there any situations in which phenylephrine is preferred to pseudoephedrine?
In the mid 2000s in the US, due to issues of drug enforcement, pseudoephedrine containing medications were brought behind the pharmacy counter and in most cases require ID, and phenylephrine was ...
5
votes
1answer
101 views
Why is the human body able to repair a broken bone and not a heart muscle?
The human body can repair skin/organ laceration, fractures, even repair nerves - albeit the duration and rate of recovery differ. For instance:
The burn scar on my arm from the hot soldering iron ...
17
votes
2answers
247 views
How does the microbial environment in your gut initiate?
Clearly, a zygote does not harbor any microbes. As it develops, and the alimentary canal tissue is differentiated, I logically assume that there is still no microbial activity in the fetus's gut. I'm ...
2
votes
1answer
114 views
Negative feedback in the fructose metabolism in liver
What happens in liver when large amount of fructose is consumed?
I vaguely remember my biochemistry lecturer telling us that the enzymes that process fructose in the liver does not have negative ...
1
vote
0answers
32 views
Where can I find approximate rates of sequestration of CO2 for different species of algae?
For a study, I want to compare the rates of CO2 sequestration and fixation of a few different species of algae.
I could not find any data on the sequestration rates. Any pointers to where I can find ...
11
votes
2answers
877 views
How do insects breathe?
Do ants even breathe? If they don't, how do they stay alive? On what resources do they depend upon to stay alive? How are they different form mammals?
5
votes
1answer
1k views
Do hot drinks cool you down?
It is quite the old wives tale that drinking a hot drink cools you down. If you don't really think about it it does seem somewhat logical: increasing temperature will cause your body to try and cool ...
3
votes
1answer
420 views
What are the units of Q10 (temperature sensitivity)?
Q10 is the increase in a rate (e.g. activity of an enzyme) observed with a 10 degree temperature increase.
According to Wikipedia:
It is apparent that the units of R (e.g. mol/g/s) cancel out, ...
5
votes
1answer
212 views
Is it purely the nervous system causing vaginal lubrication (arousal)?
My girlfriend was watching some documentary on TLC about a paralyzed woman getting pregnant. I believe that woman still has some feeling, as she spoke about feeling the effects of a bladder ...
3
votes
1answer
2k views
Why are (some) cats attracted by bleach?
(Sorry if this question is only partly biological)
I have noticed that several cats (including the one that keeps sleeping in my house), are fond of the odor of bleach (eau de Javel) and chlorine.
...
6
votes
1answer
116 views
Understanding Membrane / Resting Potential from the perspective of ions?
From wikipedia article RESTING potential: "there is no actual measurable charge excess in either side. That occurs because the effect of charge on electrochemical potential is hugely greater than ...
2
votes
1answer
142 views
Why apes started to contemplate and become altruistic? [closed]
I was asking this first on philosophy forums, but it is suggested, that answer could be found from evolutionary view of point, so here we go:
Again my question raised when thinking of myths, their ...
6
votes
1answer
346 views
What happens to a human body once a sugary snack is consumed?
I'm looking to understand the effects of sugary snacks and/or drinks on a human body. I'm particularly interested in the timing of the ingestion versus various hormonal levels that may be circadian in ...
14
votes
2answers
1k views
What actually happens when my leg 'falls asleep'?
Most people have experienced the temporary loss of feeling and tingling in their leg resulting from sitting in an abnormal position for a short while. Usually you get a loss of feeling in your leg ...
5
votes
1answer
318 views
The genetic and physiological origins of laughter?
This Wikipedia article defines laughter in many terms, such as...
"a visual expression of happiness, or an inward feeling of joy"
and
"a part of human behavior regulated by the brain, ...
7
votes
1answer
911 views
Effects of beer on muscle recovery after exercise
I noticed it several times that when I drink beer (even one bottle) after some heavy workout, the next day my muscles are more stiff than other times, and not the same way... Is it because that ...
16
votes
3answers
210 views
How is the blood volume of a living organism measured without killing it?
How is the blood-volume of an organism measured without killing it? NOTE: The blood-volume of an organism is defined as the total volume of blood present inside that organism.
