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

learn more… | top users | synonyms

2
votes
2answers
242 views

Is there a known glucosepane cross-link breaker?

I read the following on wikipedia: There is, however, no agent known that can break down the most common AGE, glucosepane, which appears 10 to 1,000 times more common in human tissue than any ...
2
votes
1answer
331 views

Why does crying lead to a running nose and reddened nose tip?

Why do we have a running nose for quite some time after crying? It persists even after we stop crying. Why is it so? I have faced this always. Also, why does our nose redden on crying for long?
2
votes
1answer
96 views

Fast standing and the heart's insufficient accommodation of the increased venous return

Assume you are 45 minutes on the supine position. Furthermore: you stand all of a sudden and fast and without sympaticus activity. The venous return (smooth musculature of vessels) accommodates ...
2
votes
2answers
1k views

Calcium levels and nerve hyperexcitation

Why does lower blood calcium levels (or lower calcium levels in ECF) cause nervous hyperexcitaton? Why does it cause over stimulation of nerves and muscles and spasmic contractions of muscles? This is ...
2
votes
1answer
141 views

Sodium levels and blood pressure

Why does low Na+ levels cause hypotension (low blood pressure). Alternatively, why does excessive intake of Na+ cause hypertension or high blood pressure? From what I understand, there are ...
2
votes
1answer
84 views

What happens during a Raynauds episode?

Raynaud's phenomenon can be a serious health issue, as the blood flow to the extremities, mainly the fingers is compromised, causing fingers to blanche, and then turn blue. Severe Raynaud's can cause ...
2
votes
1answer
2k views

What is the physiological difference between snorting/swallowing cocaine

I know that mucosa inside the nose absorbs cocaine molecules when snorting cocaine, but what difference is there compared to swallowing? Also more cocaine administration equals more cocaine molecules ...
2
votes
1answer
64 views

Antibody production in secondary immune response

Can IgG antibodies be produced in the secondary immune response without the help of T cells? Is the affinity of antibody for antigens higher during secondary immune response?
2
votes
1answer
4k views

How do inward rectifier potassium channels work in the heart?

Apparently in cardiomyocytes, there is an inward rectifying potassium channel that operates during phase 4 of the cardiomyocyte action potential. I have heard that despite this potassium channel ...
2
votes
1answer
109 views

What is the mechanism behind ventilatory acclimatization?

In my respiratory physiology lectures, my professor explained that hypoxia-induced hyperventilation occurs in 2 stages when people try to acclimate at high altitudes. My question is about the ...
2
votes
1answer
3k 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 ...
2
votes
1answer
55 views

Possible calculations with temperature, humidity, images and VIS spectrum of a plant in an Integrating sphere

I am currently working on a project which involves growing some plants in a integrating sphere made of foam. I have added temperature, humidity and soil moisture sensors as well as a Spectrometer (350 ...
2
votes
0answers
17 views

Peculiarity of chemo senses [closed]

We can easily recall our visual stimulus and auditory stimulus but why can't we recall chemical stimulus like smell and pain? We can recall a song or picture but we can't exactly recall smell and ...
2
votes
0answers
117 views

Skin extra sensitive to heat after burn

I just got my finger burnt (first degree burn $\Rightarrow$ I didn't even bother to bear the wound). It didn't hurt much, even when I pressed the wound. However, when exposed to heat (hot water, but ...
2
votes
0answers
72 views

Biology Experiment Data (Hodgkin-Huxley)

I'm doing research into the Hodgkin-Huxley Model from an electronics/mathematics perspective and I'm looking to find actual numerical results from experiments on squid axons. I want to compare the ...
2
votes
0answers
62 views

What does salt do to styes?

Styes formed in the eyes are cured by dabbing at them with lukewarm water(I saw this being done many a times as a home remedy.) At times, common salt is added to the water before dabbing. My mother ...
2
votes
0answers
2k views

Why does skin sometimes suddenly itch when you stretch it? [closed]

Sometimes, when I bend over, areas of my skin like my back can suddenly itch quite intensely. Sometimes it may be another part of my body and the pattern seems to be a part of the skin organ that is ...
2
votes
1answer
454 views

Which is the tissue damaging agent in krokodil (street desomorphine)

I've just read about krokodil and saw some quite hideous pictures about what it does to the human body. I guess just desomorphine alone wouldn't have this effect. Which ingredient(s) causes the ...
2
votes
0answers
2k views

What are potential side effects of myostatin inhibitors?

Myostatin inhibitors, which are being developed to treat muscle wasting diseases like muscular dystrophy, are likely to be abused by athletes. What are the potential long-term side-effects of taking a ...
2
votes
0answers
154 views

Size of classical liver lobule across species

A classical liver lobule is made up of a central vein and the portal triads. A typical human liver weighs around 3 lbs. , while a typical bovine liver weighs around 12 lbs. I was wondering if anyone ...
1
vote
3answers
2k views

Does Darwin's Theory of Evolution refute Terence McKenna theory “Stoned Ape” theory of human evolution?

I haven't read it but I'm asking for a quick answer. As far as I know, Terence McKenna's theory of evolution in humans main concept is that a hominid has tried in their diet psilocybin mushrooms, and ...
1
vote
3answers
346 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 ...
1
vote
3answers
1k views

Why do we exhale after we hold our breath?

I tested this out with my friends, and I find that after they hold their breath and can't hold it anymore, they exhale air, instead of inhaling air. Interestingly, they all try to inhale in as much ...
1
vote
1answer
69 views

Gastro-intestinal physiology reference

I am a physicist but I have always wanted to understand how my digestion takes place in as much detail as possible. I have no idea about books or reference on the subject of Gastro-intestinal and ...
1
vote
2answers
578 views

What gases are needed for humans to breathe?

I will be beginning a science project about sustaining life on space stations. I already know that pure oxygen is harmful for humans but would $O_2$ + $CO_2$ be enough for humans to breathe in or do ...
1
vote
1answer
203 views

How much heat can a human sustain? [closed]

For how long can a human sustain a temperature of 180 degrees Fahrenheit (82oC) without damage in a confined place? For instance, suppose a person is sitting in a steam-filled room, without external ...
1
vote
1answer
38 views

What is the so called “hepatic glucose production”

I came across this term in my readings but I do not understand how this works. Can someone direct me to some reference as to what this "hepatic" glucose production is all about?
1
vote
1answer
49 views

What is ischaemia exactly?

I think it is decreased blood supply to organs and tissues. I also think it is the stopped circulation. However, both ones cannot be right, I think. What is ischaemia exactly?
1
vote
1answer
213 views

What is the energy balance of cooking?

If I cook some food, I get apparently several energetic advantages: thermal : the temperature of the food is closer or superior to the temperature of my body or internal organs, so I do not have to ...
1
vote
3answers
97 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 ...
1
vote
2answers
385 views

Why can newborns swim?

I am wondering for someone to discuss the phenomena that newborn babies (humans) are able to submerge underwater up until a few months where that ability is lost again? What is the explanation for ...
1
vote
1answer
151 views

How does ANF increase GFR?

ANF as we know reduce the Na+ uptake and K+ removal in the distal tubules and it also functions as a Vasodialator (?) But again it says that ANF increases the Glomerular filtrate ? But if it is acting ...
1
vote
1answer
39 views

Is the sense for salt depending on the electrolyte level in our body?

I often noticed, after (heavy) physical activity like cycling, running, swimming or working an isotonic drink (to recover the electrolyte level) tastes less "salty" compared to when drinking it before ...
1
vote
1answer
38 views

How are cyclic hormones characterized?

I have a question regarding the description of a subset of peptide hormones, called cyclic hormones. Two examples of cyclic hormones would be somatostatin and melanin-concentrating hormones. I know ...
1
vote
1answer
95 views

Could light/occasional smoking strengthen the lungs?

Here's my thought process, correct me where I'm wrong. It seems the human body has thresholds. Examples: You lift too much weight, and the muscles and tendons risk serious injury, but otherwise ...
1
vote
1answer
473 views

Advantage of cup-like shape of blood cells, spores?

Mold spores sometimes have the same shape as platelets in blood. If I were designing a spore it would probably be spherical. Is there any advantage to this cup-like shape? Maybe there is some ...
1
vote
1answer
87 views

Why are new vessels more permeable in microvasculature?

I know for microvasculature New microvasculature (arterioles, venules) are always more permeable as they lack pericytes. and then I have this sentence about new blood vessels (not specific) ...
1
vote
1answer
94 views

Death because of no radio waves [closed]

I read somewhere that a man dies if he is isolated from natural electromagnetic fields and waves. (I imply fields of radio frequencies and below.) Is it true?
1
vote
1answer
3k views

Are there more/less favourable phases of menstrual cycle to donate blood?

I was wondering whether it makes a difference when during the menstrual cycle a female is donating blood in terms of: Blood quality (iron or hormones levels) Her health/safety I am aware that ...
1
vote
1answer
150 views

Is there nutrient absorption in the large intestine of hindgut fermenters?

In hindgut fermenters, plants are digested in the caecum by microbes. I want to know whether hindgut fermenters can absorb the nutrients obtained from the digestion in the large intestine because the ...
1
vote
1answer
2k views

How is ATP involved in muscle contraction?

The sliding filament mechanism as explained by my text does not elaborate on how ATP is involved in the cross bridge binding and contraction process. How does muscle contraction utilize ATP? In my ...
1
vote
3answers
164 views

Does the necessary Carbon Dioxide need to be in the atmosphere for mammals?

In the answers to this question, we've learnt that carbon dioxide is necessary for mammalian life, but is it necessary in the atmosphere/to breathe it in? Or does the act of respiration give a ...
1
vote
1answer
50 views

Double use of ATP in relaxing myosin & active transportation of calcium?

Is the ATP molecule which is bound to the myosin head for relaxation of the muscle (i.e., to break the cross bridge) also utilized for active transport of calcium to the sarcoplasmic reticulum during ...
1
vote
1answer
109 views

What specific sensory nerves act as receptors for “pins and needles” (neuropathy)?

According to this excellent answer, the difference between "pain" and "pins and needles" (neuropathy) is that different receptors (sensory nerves) trigger in reaction to different stimuli. Different ...
1
vote
1answer
140 views

Duplicity Vs. Singularity of Mammals Organs [closed]

Are there known evolutionary reasons why mammals contain 2 of some organs (such as lungs and kidneys) and only 1 of some (such as liver)?
1
vote
1answer
108 views

How Ants know about Earthquake?

How does an ant know about Earthquake is it because of an organ or due to other factors?
1
vote
1answer
56 views

Can lymph be in peripheral blood?

I read an argument that 1-3% of lymph is in peripheral blood. However, I am not sure if this lymph is about lymphocytes in peripheral blood; not lymph itself. Lymph gets exchanged between capillaries ...
1
vote
1answer
73 views

Can tubular secretion regarded as local hormone?

Tubular secretion is : The process in which ions and other waste products are transported into the distal tubules of the nephron. can it be regarded as local hormone??
1
vote
1answer
51 views

How does a blunt force stimulate histamine to develop early stages of inflammation?

I know that viruses and sharp forces can stimulate mast cells by cut or by a virus infecting them and then release histamine. How can blunt force do this and cause inflammation? It doesn't have the ...
1
vote
2answers
131 views

Is Sinus node conduction necessary for heart beating?

Assume a patient with previous cardial infaction which SA node not possible to activate action potential anymore. However, SA trying to beat unsuccessfully repeatedly waisting energy. Therefore, I ...