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19

The capture area of the eye is a bit fuzzier and harder to define than that of a camera. A camera captures consistent, fully detailed data right up to the edge of its sensor, and no data at all beyond it. Captured data is clipped by an ideally uniform sensor, augmented a bit by the lens, and is well-defined during design and manufacturing. The eye can ...


17

You are asking two questions that you think are connected but are actually not. Question 1 - What is the use of eye banks? Answer: It's to store corneas for transplant for people with cornea damage. Question 2 - What use is cornea transplant to a completely blind person? Answer: It depends. If the blindness is due to clouded cornea (several ...


14

I used to work at an eye bank so I have a bit of knowledge about this, though some of it may be out of date. There are several aspects to an eye bank. The corneas are one of the primary things that are kept for transplantation. Of course, this will not repair blindness in someone that has problems in other areas of the eye, but corneal transplants are ...


10

An older answer that referred to the physiological feats of ancient humans, and why modern humans are wimps made me look up a couple of papers on running speeds a while ago. One of the examples used to support the statement that modern humans are "wimps" is a study of ancient fossilized footprints from Australia, which claim that the individuals making the ...


9

No-one can re-implant an entire eye, because the optic nerve has been severed in one who has lost an eye. A cornea can't be grafted to a glass eye. But blindness isn't only caused by loss of the entire orbit. It's also caused by cloudy corneas, which is the purpose of eye-banks. The optic nerve is a cable of nerve fibers that carry visual information from ...


9

I found an interesting article in Scientific American (Coates, 2005), and I quote part of it: The condition of having no more than five fingers or toes [...] probably evolved before the evolutionary divergence of amphibians (frogs, toads, salamanders and caecilians) and amniotes (birds, mammals, and reptiles in the loosest sense of the term). This event ...


8

This question is at least two questions. Dividing cells In terms of a dividing human cell line, every time a division occurs the telomeres capping the ends of the chromosomes get a little bit shorter. Once the telomeres get short enough they act as a signal that triggers apoptosis, destroying the cell. There is some human-to-human variation in the initial ...


6

In short, it's because your brain processes external and self-produced stimuli differently. If someone tickles you, you feel that ticklish feeling, but when trying to tickle yourself, there is a reduction in the sensation. When you are tickled by someone, a part of your brain activates causing you to laugh, etc., but it seems that when you trying tickling ...


5

It's a conversion factor. $$ 1~lbs = 0.453592~kg \\ 1~in = 0.0254000~m $$ $$ \frac{lbs}{in^2} = \frac{0.453592~kg}{(0.0254~m)^2} = \frac{703.069~kg}{m^2} $$


4

Note: This is based on literature searches I've done a while ago out of general curiosity. I'm in no way an expert on human reproduction. If I understand you correctly you are basically asking if there are any evidence for sex biases in offspring between families, that has a heritable genetic basis. This has been an active research topic for a long time ...


3

If you with 'humans' refer to our genus Homo (which is often the case), we do have multiple species, see wikipedia for an overview. The difference to many other organism groups is just that all species except Homo sapiens are extinct. Also, taxonomic ranks below the species level - such as breed, subspecies, population and race - are very poorly definined ...


3

Humans and other animals have lots of innate behaviors that are not learned from observation, i.e. behaviors that are hard-wired into our nervous system, and this is one of them. Suckling reflexes in mammals and the Moro reflex is human babies (which we grow out of) are other simple examples. The stretching behaviours you are referring to are usually ...


3

This depends on a lot of factors, including how you take your first sip. If you sip with air, you are altering the temperature of the liquid as you sip, as well as decreasing the volume of hot liquid in your mouth, so that the increased surface area of your exposed tongue can quickly alter the temperature of a borderline scalding liquid into a non-scalding ...


2

As someone who has dabbled in both biology and programming, I assume you are referring to the theoritical ability of functional programming to simulate organic behaviour from well defined input. From that point of view, our comprehension of the human cell behaviour is currently near stone age level. The astounding diversity of homeostatic and signaling ...


2

The question you're asking is essentially a version of an old riddle: If you flip a coin ten times and it comes up heads each time, what are the odds that the coin will come up heads when you flip it for an eleventh time? And of course the answer is that the odds are fifty-fifty. You could instead argue that 10 heads in a row is evidence that the coin is ...


2

Vitamin D does not bind to Calcium. It is a pre-hormone which is converted to calcitriol. Calcitriol has an intracellular receptor (VDR) that, as a heterodimer with Retinoid-X receptor, regulates gene expression. I guess the "should not be had together" is because of possible over-absorption of Calcium. There are commercially available supplements (e.g. 1, ...


2

Short Answer What you're referring to is called Delayed Onset Muscle Soreness (DOMS). We don't really know what causes DOMS, but it's most likely caused by a cascade effect started my muscle injury. Also, we aren't sure if massages (or what type of massages) really help relieve the pain. What is Delayed Onset Muscle Soreness (DOMS)? Delayed onset ...


2

Afaik the tongue is not more heat tolerant than other parts of the body, so the minimum temperature to cause burn is about drinking a beverage having 45°C temperature for a long time (more than 5 minutes). The pain threshold of tongue is around 47°C, so you will feel when it really burns. According to studies the hedonic value of coffee has a maximum by ...


2

To add my 2 cents worth: Breathing rate and depth is regulated by chemoreceptors in the medulla. These chemoreceptors primarily respond to pH of the blood, but the pH is for an important part determined by the CO2/HCO3- equilibrium as explained by @TomD. Essentially it is the increase in CO2 that is sensed by the medulla and which increases breathing ...


2

The eyeball is basically the sclera that surrounds the delicate inner structures of the eye (see wiki on the eye). The cornea is the transparent window in front of the pupil that transmits light to the retina. It needs replacement when it turns opaque, often due to damage or infections. The cornea can be replaced on its own, without the need for ...


1

Chlorine is a reactive substance and an oxidizing agent. It can cause damage to surfaces exposed to it such as eyes, skin etc but it cannot penetrate deeper. Chlorine can damage your hair by oxidation — hair becomes rough and brittle. This is not same as hair loss — chlorine doesn't cause hair to fall out because it cannot penetrate to the follicles. See ...


1

It seems to me that really your whole question seems to be much simpler than it seems and it is just "why are eye banks called eye banks when they can't transplant eyes, just bits of them like corneas" The answer is: In the english language and in various cultures, the names of things often have a loose and not entirely accurate relationship to the ...


1

In addition to providing tissue for transplant, eye banks also provide tissue from all parts of the eye to medical schools and universities for teaching and research purposes. There are many medically relevant questions that can only be answered by examining human tissue, and eye banks facilitate this research.


1

With regard to the vacuum - Apparently nothing happens as long as you don't hold your breath, just like you shouldn't hold your breath when ascending after scuba diving and the pressure drops. See NASA's answer to the same question. Of course there's the radiation that does other funny things in space, see the NASA link.


1

I hope you might edit your question to give examples of such comparative injuries. I'm trying hard to imagine an example of this phenomenon, but I can't. The human body doesn't have a tripwire, or a lower limit of injury under which it will not respond. Normally the body mounts appropriate defenses against all injuries from the very minor, like a paper cut, ...


1

The meaning of the term microenvironment depends on the scale of the system that you're looking at. It's a sort of weasel word that loosely means "context" or "stuff in the immediate surroundings of the system of interest that has some kind of an effect on it". I've seen it used to describe everything from the chemical microenvironment of a cell (e.g. a ...


1

My experience that it depends on it. You sleep in cycles, each cycle has about a 90 min duration. I think the quality depends on how many cycles you ended. It seems like you need to sleep more by an interruption. Sleep was recorded on 10 nights in each of seven older subjects (mean age 55) and nine younger normal subjects (mean age 22). The duration ...



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