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

learn more… | top users | synonyms

1
vote
0answers
20 views

Absorption of nutrients in human beings [on hold]

I know that pulmonary veins carry oxygenated blood from lungs to heart, and pulmonary arteries carry deoxygenated/CO2 rich blood from heart to lungs. Arteries also carry oxygen-rich blood to the heart ...
0
votes
1answer
40 views

Amino Acid requirement + intake in relation to diet + meat type [on hold]

I was arguing with a friend: I said: The Yulin festivals cannot be condemned by western culture, as we also kill animals in equally cruel ways. She said: It isn't just that the killing is cruel, ...
21
votes
1answer
3k views

Why do mints make your mouth feel cold?

Why do mints make your mouth feel cold? And specifically, why does your mouth feel so cold if you eat a few mints and then drink a glass of cold water afterwards?
-1
votes
0answers
24 views

Are the three different cones really distinguishable?

Our retina has three different cones (S,M and L) for the colors blue (S), green (M) and red (L). But the sensitivity of these cones do overlap each other. For example, the S is sensitive for 400-500nm ...
1
vote
3answers
73 views

What is the actual storage form of energy in muscles? ATP or Glycogen?

I was asked this question in my latest exam. I think the answer is Glycogen because ATP doesn't store energy for a long time so it isn't the ACTUAL storage of energy. Some classmates argue that in ...
0
votes
0answers
38 views

Can defibrillation (cardiac arrest treatment) be done with a vehicle spark plug? [on hold]

Can successful defibrillation (restarting the heart after cardiac arrest) be done with a spark plug from a vehicle (possibly offroad vehicle)? Is it POSSIBLE for this to work? Let's say you are stuck ...
1
vote
0answers
10 views

Has research indicated how much koinophillia preferences are learned vs insinctual

I'm curious about rather the definition of 'normal', as it affects koinophillia & mate choice, is something instinctual or learned. To clarify I'm not asking if koinophillia itself is ...
1
vote
0answers
31 views

Would a transparent iris serve its purpose?

The function of the iris is to regulate the aperture of the pupil. How does the iris obstruct light? Is it due to the pigment present in it? Or is it just due to the sheer presence of it? I am doing ...
14
votes
1answer
152 views

What's the mechanism for being mentally tired?

I notice that after long tests, or long periods of critical thinking, my body and mind feel noticeably tired. Why does this happen? Are the neurons in my head not firing as quickly, or is there just a ...
0
votes
0answers
8 views

will 2,4 Dichlorophenoxy acetic acid be effective as an herbicide against banana and papaya

Since 2,4 D is effective against broad leaved weeds/plants, will it be effective in case of banana and papaya?
0
votes
0answers
24 views

fluid used in replacing blood for oxygen, carbon dioxide exchange during major surgical operation

Are there fluid alternatives that can be used in replacing blood for oxygen, carbon dioxide exchange during major surgical operation?
2
votes
1answer
26 views

If targeting a certain daily water intake, do you have to compensate for beverages that promote diuresis?

Please forgive my ignorance on the topic and I hope this is a "on topic" question here. It was a toss up between this SE and Physical Fitness SE but I want a more scientific answer. I came at a ...
0
votes
0answers
59 views

Why do horses recycle their endometrial lining while humans don't?

How does not recycling the endometrial lining of the uterus benefit humans (and other organisms that menstruate), while recycling it is beneficial to horses (and other organisms that undergo estrus ...
2
votes
0answers
17 views

What is the evidence that mammals are unable to process excess sodium chloride?

I grew up hearing the mantra excess salt causes heart disease I had a vague understanding that it caused deposits in the body or something. Now that I give it more thought - I come up with three ...
1
vote
1answer
30 views

Resting stage of primary oocytes

In my biology textbook, I read that the primary oocyte gets arrested in the early stages of meiosis in prophase I (diplotene stage). I wanted to know why this is so. I searched google, and this ...
2
votes
0answers
26 views

How do organoarsenics improve digestion efficiency in poultry?

It struck me as very surprising that these organoarsenic compound with structure looking not very compatible with living system is widely used as food additive to increase weight gain and improve food ...
4
votes
2answers
52 views

How does the muscle return to its resting state after muscle contraction?

I know that when ADP binds to the myosin head, it moves along and as it does so, it releases the ADP. The ATP attaches to the myosin head and releases the myosin head from the actin filament. Then the ...
3
votes
1answer
44 views

How does an octopus eye react in free fall?

according to Wikipedia: Attached to the brain are two special organs, called statocysts, that allow the octopus to sense the orientation of its body relative to horizontal. An autonomic response ...
-1
votes
1answer
50 views

Evolution & Celluar Chemistry [closed]

I'm new to this site but had a question on evolution, apologies if some of these questions seem basic but they are from a book i am reading challenging the role of chance in evolution. Taking the ...
0
votes
0answers
15 views

Lysis of bacteria by complement system

The complement system creates pores in cell membrane which leads to influx of lots of water thereby causing lysis of bacterial cell. But what I fail to understand is that if bacteria have cell walls ...
1
vote
0answers
43 views

Why do some men have patchy beards?

Why do some men have patchy beards? Or more specifically, why would some hair follicles lack sufficient 5-alpha reductase while others nearby don't when their genetic code is identical and they are ...
2
votes
1answer
31 views

Question about Enzyme Inhibition in relation to Aspirin

I've been trying to learn a bit more about pharmacology, so bear with my ignorance. In short, I see that aspirin (in part) works by inhibiting cycloxygenase isoenzymes and that this inhibiting is ...
2
votes
1answer
257 views

Where does female ejaculate actually originate from?

It's common knowledge that it's released via the urethra, but where does it originate? If it doesn't come from a part of the clitoris, then why is the clitoral glans called the clitoral glans? How ...
0
votes
1answer
41 views

A state model of sodium channels

I am studying by myself Human Physiology. I have encountered the following question: In the following given model of sodium channel with 3 states open closed blocked (which I assume means inactivated)...
0
votes
0answers
19 views

Bilirubin metabolism and UGT1A1 inhibition in human vs. monkey?

In human UGT1A1 seems to be the only relevant enzyme to glucuronidate unconjugated bilirubin into excreted forms. Is the pathway the same for e.g. the Cynomolgus monkey (Macaca fascicularis) in vivo? ...
1
vote
1answer
36 views

Question about radiation and how it affects biological systems

I'm doing research on the effects of radiation, and specifically UV, X-Ray and Gamma radiation, on biological systems at the cellular level and beyond. I understand that radiation types can be ...
1
vote
1answer
32 views

How exactly do we get “energy” from food? [closed]

I am captivated by human biology and I'm currently trying to understand the body and its processes in a greater depth. Thank you so much for your time and consideration! :-D I'm sorry for the rambling ...
0
votes
1answer
27 views

Is H antigen considered as an agglutinogen?

A and B antigens which have the potential to cause agglutination in certain cases are called agglutinogens. But, as far as I know, H antigen cannot give rise to agglutination. So can it be said that H ...
5
votes
0answers
37 views

Why do Arctic predators accumulate vitamin A?

Top predators in the Arctic are known to accumulate vitamin A, often to levels that are toxic for human consumption. A 2012 study by Senoo, Imai, et al. found that the livers of several predator ...
5
votes
1answer
106 views

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. ...
4
votes
2answers
331 views

Why does haemoglobin's affinity to oxygen decrease at high altitudes?

My class 12 NCERT book says, Pg 226 The body compensates low oxygen availability by increasing red blood cell production, decreasing the binding affinity of haemoglobin and by increasing breathing ...
6
votes
1answer
101 views

What determines whether a substance can diffuse across the blood-brain-barrier?

What determines whether a chemical substance is able to cross the blood-brain-barrier via passive, transmembrane diffusion? What structurally differentiates these chemicals?
5
votes
1answer
102 views

Why is it always Sodium that we talk of in blood pressure?

Why is that we emphasize so much on sodium in blood pressure? I understand that it is a major extracellular ion, but, it also is tightly regulated. So when something is that tightly regulated, won't ...
3
votes
1answer
101 views

Doesn't the sarcomere contract during isometric contraction?

During muscle contraction, the lenght of the sarcomere changes, length of myocyte changes and so does the length of muscle. However, if the length of muscle is not changing length as in isometric ...
2
votes
1answer
113 views

What happens when our muscle tense? [closed]

Is the tensing of muscles equivalent to stretching them? I am trying to understand what tensing of the muscles means.
3
votes
0answers
27 views

What happens to the cell during post-hypothermia?

A friend of mine said that the cell membrane somehow changes after rewarming from hypothermia and that the body does not recognize it's own cells, thus leads the immune system to attack it self. Is ...
10
votes
0answers
616 views

Why don't rats have a gallbladder, unlike other rodents?

It has long been known that rats do not have a gallbladder, though other species including humans, monkeys, cows, reptiles, dogs and mice, all have a gallbladder. In this paper from almost 100 years ...
1
vote
0answers
20 views

Is the amount of blood same in the pulmonary and systemic foetal circulation?

We learn that the stroke volume is the same for the right and left side of the heart. So the amount of blood in either circulations should also be the same. (is it? I myself doubt this statement. As ...
2
votes
0answers
39 views

When you have your gallbladder removed, how does it affect bile flow into your small intestine?

Cholecystectomy, or surgical removal of the gallbladder, is an extremely common operation around the world. The gallbladder is typically viewed as a storage organ for bile produced by the liver, but ...
3
votes
1answer
66 views

What is the oxygen carrying capacity of reticulocytes?

What is the oxygen carrying capacity of immature red blood cells, or reticulocytes? Is there any difference between oxygen carrying capacity of mature and immature red blood cells?
3
votes
0answers
17 views

How is the side-polarity of the myosin filament in myofibril maintained?

If myosin molecules are the properly oriented relative to their position in the the myosin filaments, the sarcomere is not functional. But how is the orientation of the myosin molecules determined? ...
3
votes
0answers
42 views

How does glucose delivered intraperitoneal (i.p.) get into the peripheral circulation?

Intraperitoneal delivery of drugs or fluids is something that occurs much more frequently in veterinary medicine than clinical medicine. In veterinary medicine or scientific studies using animals, ...
3
votes
1answer
46 views

Do goosebumps always appear in the same spots on the skin?

Often one gets goosebumps when one is cold. I am curious whether the precise location of the goosebumps on, say, one's leg changes from occurrence to occurrence or not? In case if their precise ...
4
votes
1answer
40 views

Do pharmacodynamics and pharmacokinetics of the drug in animals are the same as in human?

I'm trying to understand the purpose of different clinical trial phases, and the following question comes into my mind : Do pharmacodynamics and pharmacokinetics of the drug in animals are the ...
2
votes
1answer
174 views

Anatomical differences between herbivores and omnivores [closed]

What are differences of herbivores vs omnivores? I do not mean dietary differences (obviously), but physical ones. E.g., afaik herbivores have a much longer digestive tract than carnivores; then ...
1
vote
1answer
40 views

Why does ESR have to be waited for one hour?

It is said that the length of the column of clear plasma in a narrow tube left by erythrocytes which gradually sediments after one hour is the measure of ESR(erythrocyte sedimentation rate). Its ...
1
vote
0answers
25 views

What are the most efficient sources of nutrition to add lean mass? [closed]

In conjunction with an exercise routine, what sources of nutrition will best help increase lean body mass. Most non-hormonal exercise supplements risk causing liver damage and gout due to excess urea ...
1
vote
0answers
39 views

Are cold-blooded animals more energy efficient than warm-blooded animals? [duplicate]

When cold-blooded animals extract energy from glucose, do they do so in a more efficient manner than warm-blooded animals? If they aren't producing heat as a by-product, that would suggest that they'...
22
votes
1answer
6k views

How long can an octopus survive out of the water?

I saw videos of octopuses crawling on the ground and I was wondering how long an octopus can survive when out of the water? Does it depend on either its size (i.e., does a big octopus from deep sea ...
0
votes
0answers
21 views

How does excess excretion of NaCl affect Glomerular Filtration Rate and afferent arteriole size?

A toxic drug blocks NaCl resorption channels in the proximal convoluted tubule. What would happen to the Glomerular Filtration Rate (GFR) and afferent arteriole size? If a lot of NaCl is being ...