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Red blood cells are not equipped with a motor system to propel them through the blood stream. Instead, they are passively transported through the vasculature by the the pumping action of the heart. The effects of dangerous situations on the skin have to do with hormonal effects on the blood vasculature, and not with direct effects on red blood cells. ...


5

Short answer Water of 180 oF (82 oC) causes immediate scalding (thermal burn wounds). Background The severity of a scald injury depends on the temperature to which the skin is exposed, and for how long. Residential water heaters warm up tap water typically to 120 oF (48 oC). At this temperature, the skin of adults requires an average of five minutes of ...


4

This paper actually goes into the whole history of organ transplants. In short it seems to have the following effects: preservation - usually with a specific solution to help. slows down extracorporeal ischaemic damage slows down hypoxic damage slows down the metabolism (energy consumption) and thus the need for oxygen that blood provides. Remember ...


3

With arbitrarily broad meaning of "processed", yes. If absolutely nothing else, elemental purification and inorganic synthesis of something chemically resembling meat in nutrition is possible. Prohibitively expensive and stupid, yes, but possible. So then the question becomes exactly how much processing you need to do. Without clear bounds on that question ...


3

Short answer One way to distinguish between the olfactory and gustatory system in fish is by their anatomical differences. For example, olfactory receptors are clustered in the nasal region, while gustatory receptors are scattered in the head region and beyond. In turn, olfactory information is sent via a single cranial nerve to the brain, while the ...


3

Looks like some parasitoid wasps have zinc coated barbs on their ovipositors which may function to help them bore through wood and lay their eggs. Here's the blog entry about it on IFL Science, and the original article: parasitoid ovipositor specimens had a weight percentage of zinc of 7.19±3.8% (N=42) in the tip regions, which was significantly higher ...


3

It has nothing to do with blood cells per se. Blood vessels constrict in areas not necessary for flight-and-fight response (sympathetic nervous system response). By constricting blood vessels around face, blood is redirected to organs more important in resolving dangerous situations: muscles of legs, spinal cord, and brain. Same way pupils get dilated to ...


1

Totally agree with the answers already provided: It is directly caused by constriction of blood vessels in the face. However, from a behavioral perspective, I feel there is an additional function for 'turning pale', that is not yet mentioned: For social animals (such as humans), the face has great expressive value. The face turning pale might fulfill the ...


1

Blood volume is not a dimensionless number - it's a volume. Historically we used to measure this in patients or volunteers by giving a large carbohydrate molecule like a starch that is not digestible or harmful to the body. Just like every other body fluid compartment volume (i.e. plasma, interstitial fluid, intracellular and extracellular) that we have, ...



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