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

learn more… | top users | synonyms

0
votes
1answer
36 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 ...
-2
votes
0answers
25 views

Hypothetical - living as a disembodied head [closed]

I'm writing a sci-fi story where a head and part of the neck is somehow surviving perfectly normally on its own (breathing, thinking, talking etc - that's the hypothetical part) but I want to include ...
-1
votes
0answers
12 views

Peak flow meters record peak expiratory flow rate (PEFR), [closed]

Peak flow meters record peak expiratory flow rate (PEFR), the fastest rate at which air can move through the airways during a forced expiration starting with fully inflated lungs. What Factors ...
0
votes
0answers
25 views

human digestion: (spicy) food eaten at night is excreted next morning

I have noticed repeatedly, that if I eat spicy food late at night, it is excreted the next morning (after 8-10 hours). How is it possible that the digestion happened so fast? I would have expected ...
0
votes
0answers
10 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
31 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
29 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
23 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
30 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
96 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
146 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
74 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
83 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
41 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
78 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
26 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 ...
9
votes
0answers
140 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
16 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 ...
1
vote
0answers
19 views

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

Cholecystectomy, or removal of the gallbladder, is a common operation that is performed around the world. The gallbladder is typically viewed as a storage organ for bile produced by the liver. The ...
3
votes
1answer
44 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
16 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
39 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
40 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
28 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
116 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
24 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
38 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 ...
21
votes
1answer
4k 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
17 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 ...
5
votes
1answer
75 views

Blood clumping in mosquitos

Will a mosquito die due to blood clumping if it sucks blood from two persons having different blood group? What will happen in its gut? Is there any mechanism to avoid clumping ? Or mosquitos know ...
0
votes
0answers
28 views

How hydrophilic is human mucus?

I am interested in the stability of virus particles in human mucus, and how this may bias the evolution of surface amino acids in respiratory viruses. For instance if the mucus environment were more ...
3
votes
0answers
50 views

What causes anorexia nervorsa?

I've heard of anorexia nervosa being a severe loss of appetite. I'm wondering what causes such disease in humans?
1
vote
0answers
22 views

Why do the vines change their spinning direction?

Look at the vines holding onto the lattice. The "vine springs" change their spinning direction in the middle. Why? And how do they achieve this? (By the way, what's the name for this plant? Is is ...
1
vote
1answer
82 views

What causes swelling after impact?

Why does the head swell after getting hit by something hard? What is the liquid that forms after impact?
1
vote
0answers
18 views

Glycoprotein hormones metabolism

Why do the carbohydrate groups in glycoprotein hormones decrease the rate of metabolism? And increase the half-life?
1
vote
2answers
30 views

How does hypocalcaemia have an effect on the excitability of cell [closed]

Hypocalcemia increases sodium influx by leak channels. Why does this elevate the resting membrane potential and increase excitability?
3
votes
1answer
54 views

Does food continue to stay sequential once it is inside my body?

I may be very off on many scientific details here, but I'm always all ears. As far as I understand, any food that is eaten goes to the stomach, gets broke down even further into smaller food ...
2
votes
1answer
83 views

Are the cells (structures) of deep sea fish different? And can they survive in shallow water?

In the deep oceans the pressure is enormous. But still there are fish living. But are the cells of them different from fish who just live at the surface of waters? For example, are the cells smaller ...
2
votes
0answers
66 views

Can one eye affect the other eye's low-light adaption?

This previous question addresses how long eyes need to adapt to darkness and reach full contrast. My question is how does one eye affect the "transition" and/or efficacy of this "night vision" of the ...
0
votes
0answers
24 views

Determination of Ageing by ECG inclusions/exclusions?

I am studying ageing and considering ECG signal because of its high sensitivity in theory (escardio). Some factors Sensitivity Gender Medical treatment ... Benchmark: RTG dental + wrist ...
5
votes
1answer
250 views

What is the maximum altitude where humans can survive?

What is the highest altitude that a human can survive without being pressurized? Let's assume that oxygen and heat/insulation are not the limiting factors? Why I asked.
12
votes
1answer
148 views

Why do I see different hues of colors between each of my eyes?

Frequently, I see colors with a slightly different hue when looking through my eyes individually. The right eye is more red-tinted ('warmer' hued) and the left is typically more blue-tinted ('cooler' ...
0
votes
1answer
100 views

When was the last common ancestor of pig and human?

Some religions regard pigs as unclean on the grounds that pig flesh is closest in composition to human flesh. I don't believe this for one instant, but it got me thinking, just how close is pig and ...
1
vote
1answer
124 views

How do cellular waste products enter arterial blood?

I recently learned that blood in renal arteries contains waste materials, which is filtered via nephrons in the kidneys. My question is, how are these waste materials getting into the arterial ...
4
votes
1answer
135 views

Why are some human injections intraperitoneal?

In humans, what benefit do intraperitoneal (IP) injections(old/cheap rabies vaccines, or cancer related injections) offer versus traditional intramuscular injections? For example, where I live, the ...
0
votes
1answer
56 views

How body loses more fat in CO2 form than in sweating form? [closed]

Yesterday, I saw TV Game Show. There is question like this: Body loses more fat in which form? It gave 4 options: 1) CO2 2) sweating 3) xxx 4) xyz sorry i didn't remember 3 & 4 options. ...
6
votes
1answer
602 views

Why does a fetus drinks and urinates into the amniotic fluid?

I was reading this website saying that fetuses urinate into the amniotic fluid. It also mentioned that, because we drink the amniotic fluid, we’ve been drinking our urine for months. However, why do ...
6
votes
1answer
63 views

How can hyperthyroidism induce osteoporosis?

It says in my physiology notes that hyperthyroidism can cause osteoporosis. I've been trying to figure out how this could be possible for a little more than an hour now. Every article that I look at ...
2
votes
1answer
76 views

How are isovolumetric contraction and afterload related in the cardiac cycle?

In the cardiac cycle isovolumetric contraction occurs and causes a pressure gradient. The "afterload" is the pressure exerted on the ventricle from the artery. Is the afterload the cause of ...