Tag Info

Hot answers tagged

16

This is called a phosphene — the experience of perceiving light in the visual cortex without light actually entering the eye. This commonly happens due to stimulation of the retinal ganglion cells by something else. The most frequent source in normal individuals is pressure to the retina (e.g. rubbing a closed eye.) It is also possible for phosphenes ...


12

Because mammary glands define us (mammals), the genetics of the ability to make milk has been of interest.[1] Because we consume milk, we have a dairy industry. Because the industry places a monetary value to certain milk constituents, the genetics of milk component production has been a viable area of study[2]. Since you are talking of cream production, ...


6

1) A hot bath, or soak in hot water raises our body temperature. Several benefits of this rise include: Improved blood circulation, Improved lymph circulation, detoxification, increased metabolism and calmer nervous system. 2) As our body temperature rises we sweat. Sweating helps to bring toxins to the surface of our skin so they can be eliminated through ...


5

For treatment reasons cortisol is named Hydrocortisone (probably to avoid problems with the similar names) and this is often only referenced to as cortisone (although this is not correct). Cortisol (Hydrocortisone) is the active form, while cortison is not. See here for some more details. Glucocorticoids (like Cortisol or Prednisolone) suppress acute ...


5

I think this question has more to do with kinetics / transport phenomenons than biology, but that's okay, everything is connected especially my computer to the internet. ;-) The basic idea behind transport phenomenons is that there will always be a flux of quantitative properties (e.g. charges, particle number, entropy, volume, etc...) where the qualitative ...


4

I think inf3rno's answer is very complete, so I will just be adding some notes that might help OP understanding what's happening. Say that we increase the intracellular concentration of potassium by 10 mM, a +1 valence ion which contributes to POSITIVE membrane potential. Let's say we do that, in an in vitro cell model, using a syringe with only K⁺ ...


4

Prions are misfolded proteins with abnormal tertiary or quaternary structures. That grants them resistance (to some extent, at least) to proteases (1). Also researchers believe that prions are able to replicate (2), by changing the structure of other proteins. Regarding the gastrointestinal barrier, that isn't exactly true. It has been shown that small ...


3

Check out Van Der Pol (chaotic) oscillator. It can be used to model heart rhythms. If a stimulus is applied to the oscillator, it will return to the curved envelope discussed in the article. However, if "pushed just right", the oscillator's current state will be pushed towards the very center of the loop, and it will stop oscillating. This is the mechanism ...


3

Anti-oxidants affect human metabolism by altering the redox states of the cell and redox-regulated functions and signaling mechanisms. The following quotes are from The Redox Stress Hypothesis of Aging (Free Radic Biol Med. Feb 2012) More recently, in a major conceptual shift, ROS have been found to be physiologically vital for signal transduction, ...


3

Yes, humans do have the hyaloid canal. Schematic diagram of the human eye (reference) For function and other information, please refer to this journal article.


3

There are differences in metabolism, and the "calories in" part is the one which differs more than the "calories out" part. People do lose different amount of calories for the same action, but for mostly mechanical reasons. If a 50 kg person walks up a mountain at 3 km/h, and a 100 kg person walks up the same mountain at the same speed, the 100 kg person ...


3

Eating many small meals or eating large meals is irrelevant. The only thing that matters is getting the right amount of calories needed for your body to function properly. Fat accumulation does not happen if you do not go over your daily calorie limit. After a big meal your food is not only stored as fat but as a polysaccharide form of glucose called ...


2

Afaik you can describe the potentials between the two sides of the cell membrane using the Nernst-equation. Yepp wikipedia writes the same here. Membrane potential is a very important thing, because human cells require stable internal concentrations of Na+, K+, Ca2+, etc... in order to work properly. These concentration can depend on species, for example ...


2

What you might be experiencing is olfactory fatigue, the temporary, normal inability to distinguish a particular odor after a prolonged exposure to it. It's a form of neural adaptation, a change over time in the responsiveness of the sensory system to a constant stimulus. This adaptative mechanism might prevent the overloading of the nervous system. ...


2

Chris is right, I just want to extend his answer a little bit more. The presence of corrosion and the corrosion speed highly depends on the concentration of the acid, which is very low (0.5% according to Chris) in this case (considering that ccHCl is about 35-40%). According to wikipedia the vapour pressure of water is about 2645 kPa while the vapour ...


2

This is a draft. How do the pharmacodynamics of the NSAIDs differ - -? Merck's manual ch. 36 to start little bit at an introductory level: The anti-inflammatory activity of the NSAIDs is mediated chiefly through inhibition of biosynthesis of prostaglandins (Figure 36–2). Various NSAIDs have additional possible mechanisms of action, including ...


2

That "red pulp" spaces you're referring are not blood vessels but, in fact, thyroid follicles that selectively absorb iodine from the blood for production of thyroid hormones and storage of thyroglobuline. So, they act as a reservoir of the materials used by the thyroid's epithelial cells, also called follicular cells, to produce thyroid hormones (T3 and ...


2

TL;DR the huge block of text: The innate immune system only recognizes certain antigens, called PAMPs. The activate immune system usually requires the immune system, but it can get around this in some cases. You're on the right track. Pathogen-associated molecular patterns (PAMPs) Innate immune cells such as macrophages and denritic cells ...


1

Your vocal chords vibrate to produce a tone, but your mouth shapes that tone into the sounds that make up voice. If your vocal chords fail or are removed, the electrolarynx can be used to vibrate the throat for you, but your mouth still needs to shape that sound into words. Because the electrolarynx produces a mechanical buzzing vibration, you get mechanical ...


1

You may want to look into "Evolutionary - Developmental Biology", which deals with how an embryo develops into a grown organism. Thus, by combinatorial specifying the identity of particular body regions, Hox genes determine where limbs and other body segments will grow in a developing embryo or larva. A paragon of a toolbox gene is Pax6/eyeless, ...


1

For a bit of background, this test was devised by Nobuyuki Kayahara and it was originally thought that it shows the dominance of one part of the brain to the other. This was later on discarded as a misconception (reference). It is now widely believed that the clockwise - counter-clockwise rotation is a phenomenon called Bistable perception (Reference 1 and ...


1

I agree with Armatus, however I feel his answer incomplete. Sodium (along with chlorine) is the most important ion in the blood if we are talking about osmolarity and water transport. Water wants to move to the high osmolarity places so its transport is mainly controlled by the transport of sodium through selective sodium channels. This is not just about ...



Only top voted, non community-wiki answers of a minimum length are eligible