The study of the normal function of living organisms and the means by which it is achieved.
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
156 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 ...
3
votes
1answer
91 views
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 ...
4
votes
3answers
79 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.
5
votes
1answer
114 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 ...
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 ...
6
votes
3answers
100 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 ...
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 ...
23
votes
1answer
366 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
0answers
66 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 ...
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 ...
10
votes
1answer
104 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 ...
5
votes
1answer
99 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 ...
2
votes
1answer
111 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 ...
2
votes
1answer
351 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 ...
1
vote
0answers
29 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 ...
6
votes
1answer
152 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 ...
3
votes
1answer
398 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, ...
3
votes
1answer
1k 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
112 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
138 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 ...
7
votes
1answer
141 views
Why are some menstrual cycles irregular?
A friend of mine asked me this today, and I didn't know. I remember studying the menstrual cycle a few years ago, but I can't remember the details (other than it was very hormone-related), and so I ...
5
votes
1answer
965 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 ...
5
votes
1answer
196 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 ...
8
votes
2answers
216 views
Below which temperature human muscles don't work?
When one exposes theirs body parts to cold environment (especially foot and hands), they may be numb, with temporarily blocked both muscles.
What is typical body temperature below which human muscles ...
5
votes
1answer
298 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, ...
6
votes
1answer
318 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 ...
4
votes
0answers
67 views
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 ...
14
votes
2answers
950 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 ...
9
votes
1answer
94 views
Were dinosaurs 'hot-blooded' or 'cold-blooded'?
Were dinosaurs hot-blooded or cold-blooded? NOTE: The popular term 'hot-blooded' means having an internally maintained average body temperature, which is generally more than that of the surroundings, ...
16
votes
3answers
204 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.
14
votes
1answer
6k views
Why is coffee a laxative?
How does caffeine (or any additional agents) act as a laxative when ingested? I'm interested in the metabolic/signaling pathway.
7
votes
1answer
859 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 ...
6
votes
3answers
307 views
Do men have more extreme variations than women?
This question was considered unsuitable for Skeptics and I think it is more suited to BIology than Cognitive Sciences
I was reading this article which I found interesting. It is not supported with ...
11
votes
2answers
201 views
Is the 'fluttering feeling' when under stress neurological or physical?
I'm sure that everyone is familiar with the sensation commonly known as "butterflies in the stomach". It is commonly experienced during periods of anxiety or stress (e.g. before high stakes job ...
9
votes
2answers
194 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?
9
votes
1answer
76 views
To which distinctions does the term “hymenoptera” refer?
Hymenoptera is an order of insects that includes bees, ants, and wasps. A quick search gives the following etymological analysis of the term hymenoptera.
hymen (membrane) + pteron (wing)
Does ...
8
votes
2answers
1k views
How do the lungs act as a sieve to trap blood clots?
Does anyone know? I'm curious to find out as my human anatomy and physiology book doesn't go into much detail on how the lungs function as such
8
votes
3answers
179 views
Why is blood pressure higher the more distal an artery is?
Why is blood pressure generally higher in more distal arteries?
11
votes
2answers
822 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?
8
votes
1answer
115 views
What are the effects of caffeine on the mammalian circulatory system?
A friend of mine told me an anecdote about his mother, who drank too much caffeine, to the point she became hypotensive and would pass out. Because caffeine acts as a stimulant, I'm assuming the ...
12
votes
2answers
217 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 ...
11
votes
3answers
254 views
How did the huge dinosaurs cope with gravity and loads on bones, etc.?
It's very costly to be a huge animal. Your mass grows in cube when you scale up, but you still only have two/four legs to support the same weight. This increases the pressure that your body needs to ...
4
votes
1answer
251 views
Does Amphibian embryo's blastocoel become a primitive yolk sac without yolk?
The mammalian blastocoel becomes yolk sac without yolk according to my professor. I have not found any evidence that such a thing happens in amphibians like frog.
I need to be able to compare and ...
5
votes
2answers
245 views
How are the gene sequences of individual sperm and egg cells “randomized”?
What I mean by "randomized" is, in the place where an egg cell or sperm cell is made, what is the mechanism by which each one is not made identically? Though I am a layman, I'm pretty sure that if the ...
14
votes
3answers
308 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 ...
12
votes
1answer
477 views
Why do some mammals not have testes in a scrotum?
Coming from an evolutionary approach, Is the only purpose of a scrotum to regulate the temperature of the testes?
Knowing all mammals are warm blooded, shouldn't all mammals have testes in a ...
8
votes
3answers
221 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?
17
votes
2answers
241 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 ...
