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

learn more… | top users | synonyms

5
votes
1answer
63 views

Case study and speculations on the brain of Edward Mordake

I am very interested in the case of the man named Edward Mordake who lived in the 19th century. In particular, he had two faces. If you have not heard of this man, please, search this up as there are ...
9
votes
2answers
183 views

Should we induce fever to assist healing?

I am currently reading "The Fundamentals of Anatomy Physiology" 10th edition, and have found it an incredibly interesting book. I have just been reading about the lymphatic system, and the various ...
4
votes
1answer
45 views

What is the relationship between W, X, Y and P, M retinal ganglion cells?

In Guyton and Hall Textbook of Medical Physiology (12e) the retinal ganglion cells are classified into W, X, and Y types. However in Gray's Anatomy (40e) they are classified into Midget and Parasol ...
6
votes
1answer
117 views

Do people with congenital analgesia feel cold?

There are a few diseases that cause an insensitivity to pain. This question asks about the relationship between the cold and pain, which got me thinking: Is shivering a response driven by the ...
3
votes
1answer
78 views

Is the swimming pool water harmful to frogs who jump in? If so, how?

Here is an odd question: Frogs have permeable skin. Indeed, via capillary action, frogs absorb water through their skin. Chlorine is in principle a harmful substance. I am sure what percentage of ...
1
vote
1answer
16 views

does phagocytosis dependent on opsonization?

does phagocytotic activity of macrophages and neutrophils depends on opsonization by IGg (antibody) and C3 complex,if it does, so then why macrophages and neutrophils are categorized in Innate immune ...
4
votes
1answer
231 views

Relationship between nerves and axons

I just wanted to get a realistic viewpoint of our nervous system. I understand arteries and veins, but I wanted to know how similar our nervous system is to that? I understand we have neurons ...
0
votes
1answer
49 views

Drinking soda triggers tingling on a tiny spot on my upper back… but how? [closed]

The title pretty much says it all. Yes, I know it doesn't make sense. That's why I'm baffled. For the past week or two, I've noticed that drinking soda seems to cause a tingling/stinging sensation ...
10
votes
4answers
836 views

Do tall people have more cells?

Within a single species, how does the relative number of cells in the body relate to the relative size of the organism? Let's say we take two humans, one of them is 6 feet tall and the other one is 5 ...
2
votes
3answers
96 views

What is the difference between meristem and bud?

Keep reading both terms quite frequently while studying plant physiology. I did some research trying to establish their differences and I learnt that meristems are undifferentiated cells that can ...
6
votes
1answer
47 views

What is the top speed of muscle contraction?

Currently I am looking into what muscles groups are most used during a football kick. I have a hypothesis that the quadriceps are not as used as most people think because the momentum the swing ...
1
vote
1answer
42 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 ...
3
votes
2answers
51 views

Bernoulli’s Principle in the Cardiovascular System

Below are graphs which illustrate the cross-sectional area, velocity, and fluid pressure through each vascular segment of the cardiovascular system. It makes sense that velocity and cross-sectional ...
0
votes
1answer
595 views

What are the risks of elevating the legs too regularly and when tired?

I started to to think the pathophysiology of elevating legs high next to the wall too often and when you are tired. I think possible manifestations some damage to valves of the veins (No!) because ...
5
votes
1answer
291 views

Would my hands sweat this much if I wasn't wearing gloves?

I've wondered about this for a long time, and hopefully someone here has a reasonable answer. I'm a cell and molecular biologist, and much of my time at the bench is spent wearing (usually nitrile) ...
5
votes
2answers
43 views

Why do epithelial cells arrest in response to serum?

Primary epithelial cells, for example human mammary epithelium, fail to proliferate (arrest) in serum-containing medium. Therefore, a common growth medium for epithelium contains pituitary extract ...
2
votes
2answers
37 views

How do t-lymphocytes become mature if thymus has lost its function?

The development of t-lymphocytes are done by thymus and we also know that the thymus degenerates before puberty and we also know the maximum lifespan of WBC's is 15 days. So, how do t-lymphocytes ...
0
votes
1answer
40 views

Would a human survive eating only living ants?

After reading an admittedly foolish question about 1 googol ants vs. 1000 humans, I had a question. Could a human survive solely on eating ants (common ants, not the stinging kind, or leafcutters ...
2
votes
0answers
13 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 ...
5
votes
1answer
67 views

Where do most mutations come from, mitosis or meiosis?

According to this (old) paper there are 10 times more mutations during meiosis than during mitosis. One reason for that is that recombination often causes replication error and therefore mutations. ...
0
votes
0answers
46 views

How calorie intake affects weight gain?

There are ton's of textbooks and websites that say that if you want to gain weight you have to increase your calorie intake. My question is how is it possible for a body to take in more calorie than ...
2
votes
1answer
65 views

How does Celiac's Disease cause people to stop growing?

In all of the sites I've looked on, one of the symptoms of Celiac's Disease is the failure to grow in children. Why would an immune attack against gluten cause stunted growth? Celiac.org states: ...
5
votes
2answers
799 views

How is membrane capacitance related to the increased speed of saltatory conduction?

Here is the original question which inspired my question. As explained by the answers there, the reason saltatory conduction in myelinated neurons is faster than non-myelinated conduction is because ...
2
votes
1answer
22 views

Physiology of tricuspid and bicuspid(mitral) valves

The tricuspid and bicuspid valves are atrioventricular valves. Both are valves that prevent backflow of blood pumped from the atria to the ventricles. However, the former has 3 "flaps" while the ...
2
votes
0answers
47 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 ...
17
votes
3answers
1k views

Why does the face turn pale in dangerous situations?

I know what the effects are of a dangerous situation on the brain, i.e., an activation of the hypothalamic-pituitary-adrenal (HPA) axis which eventually results in an increased heart rate and elevated ...
4
votes
1answer
60 views

How are smell and taste in fish differentiated?

The senses of taste and smell in different fish classes are described as two distinct senses; smell is mediated by the nasal openings, and taste by epithelial taste buds. They are both forms of ...
13
votes
1answer
1k 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 ...
7
votes
1answer
162 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 ...
30
votes
5answers
2k views

Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)

Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am ...
0
votes
1answer
89 views

How can succinylcholine cause myorelaxation?

I first thought that this is because of prolonged depolarisations. However, I am not sure anymore, because after reading PubChem, the only possible pathways are are Choline agonist. So I would say ...
3
votes
1answer
31 views

How do cold conditions help organ transplants?

Body organs are kept cold in-between explanting them from the donor and implanting them in the new host. How do these cold conditions help organs to stay viable while they haven't fresh blood, energy ...
4
votes
2answers
114 views

Can carnivores survive on a (processed) vegetarian diet? Why or why not?

There are many differences in for example the digestive system between carnivores, herbivores and omnivores. It seems that in certain kinds of species adaptability with respect to diet is possible. ...
1
vote
1answer
122 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 ...
4
votes
1answer
184 views

How efficient is the human body at metabolizing food?

My friend and I were having a discussion over how "efficient" human digestion is. If a human ate a 1000 calorie hamburger, how many of those calories (how much energy) does the body process into ...
3
votes
2answers
56 views

Determining how much energy a plant takes in?

I asked a question on WorldBuilding.SE, "Are diamond berries possible?". This led to asking a question on Chemistry.SE about the amount of energy required to burn a 1 ct. diamond (−6.527kJ). The ...
22
votes
2answers
2k views

Why does an electrical shock freeze up muscles?

Why is it when someone comes into contact with an electrical supply that their body freezes up and is unable to move away from the electrical source? Can someone explain this through a physiological ...
1
vote
0answers
25 views

classical conditioning paradigm for hippocampal learning

I wanted to know what a suitable classical conditioning experiment would be to analyze learning and memory capabilities in rodent models with respect to hippocampal long-term potentiation. For ...
21
votes
3answers
377 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.
8
votes
3answers
196 views

How does one maintain balance sleepwalking?

Anectodal. Feel free to shoot it down. Walking is an acquired skill; As far as I'm concerned exhaustion causes disorientation. Even after waking up it sometimes takes a second or so to get balanced. ...
3
votes
1answer
79 views

What is the impact of stress on the human body?

Can stress trigger any changes in the human body? I'd like to know more about things less commonly known than, for example: sweating and tiredness. What are the long term risks of chronic stress? Do ...
7
votes
1answer
136 views

Counterintuitive action of Vitamin D?

Vitamin D acts in a way which to me is counterintuitive. It functionally supplemets Parathormone. It in the intestinal tract steps up calcium absorption by altering nuclear gene expression and also ...
9
votes
1answer
122 views

What is the convention for log notation in biology?

I'm reading through some oldish (1980s) papers on length-weight relationships in fish and crustaceans. Many report log-log relationships without specifying whether this is natural log, base 10, etc. ...
2
votes
2answers
162 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 ...
7
votes
1answer
159 views

Why is the brain dependent on glucose?

The strict dependence of the (human) brain on glucose has always been puzzling to me. While ketones can substitute for a portion of the brain's energy needs, it cannot substitute completely: blood ...
1
vote
1answer
40 views

Does creatine-phosphate (CP) supplementation regenerate NADH?

I have the following facts: It is possible to convert ATP <-> creatine vice-versa. (ref - non scientific) CP supplementation protects against metabolic syndrome. ref1 ref2 Fructose digestion ...
1
vote
1answer
104 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
1answer
34 views

Are there fish with a double circulatory system?

Our courseware materials say there are such fish, but the internet suggests fish only have a single circulatory system. Thanks!
4
votes
0answers
53 views

What are those visual and auditory reflex controlled by the midbrain? [closed]

The midbrain is a centre for certain visual and auditory reflexes. But what are those reflexes exactly? My study book says that these reflexes are, e.g., responsible for moving the eyes to view ...
-5
votes
1answer
104 views

Why do fingers swell during cold winters?

When exercising, tissue in the hands may swell. This may be caused by the muscles generating heat, which leads to blood being pushed to the vessels closest to the surface of your body to dissipate the ...