Science Zone: HEALTH

Why Healing Wounds Itch?

<div xmlns='http://www.w3.org/1999/xhtml'>We are told that if a cut is itching it is healing, and that scratching itches is bad for healing, why have we evolved this tendency to cause the healing cut to itch? 
 
Answer 
There are special nerves in the skin, and this has only been discovered in fairly recent times as in the last few years, but there are itch specific nerve fibres in the skin, and their job solely is to signal to the A comparative picture of untreated 7-days-healed road rash in the form of a scar one year later. 
 
Fresh wound is on the right, and scar is on the 
left spinal cord that an area of the skin is being irritated in a way that we would perceive as itchy. 
 
Those nerve cells are activated in a number 
of ways. One of them is mechanically. So, if you have an insect crawling on you for example, the insect crawling over your skin elicits the right kind of stimulus that those nerve cells are interested in, 
and they are triggered. So you are therefore paying attention to that bit of 
skin because there might be a bug which is biting you, which might be about to give you malaria or something. 
 
So that's the first point, it’s mechanical. 
The nerve cells are also sensitive to chemicals and there are certain chemicals which when you put them in your skin, 
they're irritants. As a result, they make you think, “Oh! I've got an itchy patch of skin again.” You pay attention and you 
brush away the irritant chemical. 
 
Now when you have a wound, the wound closes by cells around the margins of the 
wound, proliferating, in other words, growing and they then migrate from the 
margins of the wound, down into the base of the wound. They actually follow the 
electrical gradient, a guy in Aberdeen discovered in the last 5 years or so that 
the inside of the wound is at a different voltage than the margin, and the cells flow down this electrical gradient, so they know where the base of the wound is. 
They then unite with their cellular counterparts, and stitch themselves into 
place. Then they start to contract, contractile filaments which pull the wound closed. 
 
So as they do that, they're eliciting a mechanical stress which the itch sensitive nerves will respond to and at the same 
time, there are various other factors which 
get released in a healing wound, chemicals which provoke healing in the wound, but also, up-regulate the activity of these itch sensitive nerves. 
 
So therefore, a wound that's closing up will feel itchy for mechanical and chemical reasons which are precisely the reasons why those nerve cells get stimulated in the 
first place. 
So that's the reason.</div>

Why Healing Wounds Itch?

We are told that if a cut is itching it is healing, and that scratching itches is bad for healing, why have we evolved this tendency to caus...

10 Things You Need To Know About Your Brain

<div xmlns='http://www.w3.org/1999/xhtml'><head>The Brain</head> 
 
The human brain is the most complex and least understood part of the human anatomy. There may be a lot we don’t know, but here are a few interesting facts that we’ve got covered. 
 
1. Nerve impulses to and from the brain travel as fast as 170 miles per hour: 
Ever wonder how you can react so fast to things around you or why that stubbed toe hurts right away? It’s due to the super-speedy movement of nerve impulses from your brain to the rest of your body and vice versa, bringing reactions at the speed of a high powered luxury sports car. 
 
2. The brain operates on the same amount of power as 10-watt light bulb: 
The cartoon image of a light bulb over your head when a great thought occurs isn’t too far off the mark. 
Your brain generates as much energy as a small light bulb even when you’re sleeping. 
 
3. The human brain cell can hold 5 times as much information as the Encyclopedia Britannic Or any other encyclopedia for that matter: 
Scientists have yet to settle on a definitive amount, but the storage capacity of the brain in electronic terms is thought to be between 3 or even 1,000 terabytes. The National Archives of Britain, containing over 900 years of history, only takes up 70 terabytes, making your brain’s memory power pretty darn impressive. 
 
4. Your brain uses 20% of the oxygen that enters your blood stream: 
The brain only makes up about 2% of our body mass, yet consumes more oxygen than any other organ in the body, making it extremely susceptible to damage related to oxygen deprivation. So breathe 
deep to keep your brain happy and swimming in oxygenated cells. 
 
5. The brain is much more active at night than during the day: 
Logically, you would think that all the moving around, complicated 
calculations and tasks and general interaction we do on a daily basis during our working hours would take a lot more brain power than, say, lying in bed. Turns out, the opposite is true. When you turn off your brain turns on. Scientists don’t yet know why this is but you can thank the hard work of your brain while you sleep for all those pleasant dreams. 
 
6. Scientists say the higher your I.Q. the more you dream: 
While this may be true, don’t take it as a sign you’re mentally lacking if you can’t recall your dreams. Most of us don’t remember many of our dreams and the average length of most dreams is only 2-3 seconds–barely long enough to register. 
 
7. Neurons continue to grow throughout human life: 
For years scientists and doctors thought that brain and neural tissue couldn’t grow or regenerate. While it doesn’t act in the same manner as tissues in many other parts of the body, neurons can and do grow throughout your life, adding a whole new dimension to the study of the brain and the illnesses that affect it. 
 
8. Information travels at different speeds within different types of neurons: 
Not all neurons are the same. There are a few different types within the body and transmission along these different kinds can be as slow as 0.5 meters/sec or as fast as 120 meters/sec. 
 
9. The brain itself cannot feel pain: 
While the brain might be the pain center when you cut your finger or burn yourself, the brain itself 
does not have pain receptors and cannot feel pain. That doesn’t mean your head can’t hurt. The brain is surrounded by loads of tissues, nerves and blood vessels that are 
plenty receptive to pain and can give you a pounding headache. 
 
10. 80% of the brain is water: 
Your brain isn’t the firm, gray mass you’ve seen on TV. Living brain tissue is a squishy, pink and jelly-like organ, thanks to the loads of blood and high water content of the tissue. 
So the next time you’re feeling dehydrated get a drink and keep your body hydrated. 
 
Credit: <a href=' http://icantseeyou.typepad.com'>ICan't See You</a></div>

10 Things You Need To Know About Your Brain

The Brain The human brain is the most complex and least understood part of the human anatomy. There may be a lot we don’t know, but here a...

Skin As Body Temperature Regulator

<div xmlns='http://www.w3.org/1999/xhtml'>The skin as we all know is the largest organ in the body. Also with exception of the bones and cartilages, it's the toughest tissue in the body. It does live up to its status by carrying out numerous functions such as protection, excretion, storage of food, sensitivity, regulation of the body temperature, production of vitamin D through the early sunshine and so on. 
 
Today we are going to see how the skin regulates the body temperature especially in we homoiothermic animals; animals with constant body temperature. 
 
This is truly amazing as how the skin keeps the body temperature constant regardless of changes in external environment though the liquid tissue cell (blood) also plays a role at body temperature regulation. 
 
On a hot day or weather, there's usually an increase in the temperature of the environment and the skin carry out the following processes to get rid of excess heat and thus to keep the body temperature constant. 
 
VASODILATION: 
There is a dilation of the capillaries near the skin surface and a constriction of those in the deeper layer. The impact of this is a large volume of blood flow close to the surface of the skin such that there's a loss of heat via the three mood of heat transfer namely; conduction, convection and radiation. 
 
DECREASE IN METABOLIC RATE: There is a reduction in metabolic activity by the skin or body and this reduces the heat released by metabolic activity and thus heat production is reduced. 
 
LOWERING OF HAIRS: We usually notice that the hairs especially those on the hands and legs rise and fall. Yes they rise and fall. 
During hot days, the hair erector muscles relax causing the hairs to lie flat on the skin surface. This expose most of the air trapped by the hairs and also heat from the body is lost as the air evaporates. 
 
SWEATING: 
The sweat gland is usually active during hot periods and there's large sweat production. As the sweat evaporate from the skin, latent heat of evaporation is also extracted from the body hence the heat of the body is reduced. 
 
On a cold day or weather, the following processes are done by the skin to regulate the body temperature. 
 
RAISING OF THE HAIRS: 
The hair erector muscle contract to raise the hair and trap more air during a cold weather. Since air is a bad conductor of heat, the layer of air next to the skin acts as an insulator and prevent heat loss from the body and conserves the normal body temperature. 
 
VOSOCONSTRICTION: There's constriction of capillaries close to the skin surface and also a dilation of capillaries in deeper layer of the skin. This brings about small volume of blood flow near the skin surface and hence prevents loss of heat and conserves body heat or temperature. 
 
INCREASE IN METABOLIC ACTIVITY: The skin increases the metabolic activity of the body especially the respiratory activity of the liver that release large amount of energy and heat. This help to generate the heat necessary to keep the body's temperature from dropping during cold weather. 
 
SWEATING: 
THE sweat gland become inactive on a cold day and hence there is very little production of sweat that gets evaporated thereby conserving the latent heat of vaporization and rather use it to keep the body temperature constant by ensuring no drop 'in temperature rate throughout the body. 
This is the very reason</div>

Skin As Body Temperature Regulator

The skin as we all know is the largest organ in the body. Also with exception of the bones and cartilages, it's the toughest tissue in t...

SKIN AS BODY TEMPERATURE REGULATOR

SKIN AS BODY TEMPERATURE REGULATOR

The skin as we all know is the largest organ in the body. Also with exception of the bones and cartilages, it's the toughest tissue in t...

WHY WE URINATE MUCH AND OFTEN ON A COLD WEATHER OR DAY

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No one can claim that he's oblivious of the fact that we tend to urinate more and often during cold weather. Yes you heard me right! 
 
But why is it so? 
Well let me address the question once and for all. 
 
First! How does the body react during cold and hot weather with regard to even temperature distribution through out the body. 
 
But then when does one feel warm and cold? 
I mean how does the body cope with hemostasis, to sound less complex the regulation of the body's temperature in order to attain and maintain a fairly constant temperature rate. 
 
The blood and the skin see to that. 
The blood cell does its by even distribution of blood around the body to ensure an even body temperature. 
To be precise, the blood disperse the temperature of a particular part of the body to all other parts of the body. <a href="http://sciencezone12.blogspot.in/2015/02/skin-as-body-temperature-regulator.html/">The skin does its as body temperature regulator</a> 
 
The body is usually warm on a hot day as a result of heat from the sun and high metabolic activity in the body. When the body is warm, there's a stimulation for sweat production and this is due to the high metabolic activity of the liver which heats up the body. 
 
For the sweat to be evaporated from the body, latent heat of vaporization is derived from the body and thus the body's temperature is continually reduced as the sweat evaporate. 
This and cold weather bring about the sensation of cold stimuli while hot weather and high metabolic activity within the body lead to warm sensation we feel. 
 
Acknowledging this, it's also important to understand how the body dispose sweat in each atmospheric condition and thus why we urinate much and often during cold weather or atmospheric condition than the warm one. 
 
During hot weather, the skin helps the liver dispose excess salt or sweat produced by the sweat gland through body sweating because the sweat gland is highly active and produces high amount of sweat. 
 
Unlike hot atmospheric condition, the sweat gland is inactive during a cold day and produces very little sweat. The effect of this is a drastic reduction of heat or sweat loss through evaporation. Not only does this result to body heat conservation but also result to the skin not excreting excess salts or sweat and then the sweat become excreted by the liver as urine. 
That's why we urinate much and often on a cold weather or day.</div>

WHY WE URINATE MUCH AND OFTEN ON A COLD WEATHER OR DAY

No one can claim that he's oblivious of the fact that we tend to urinate more and often during cold weather. Yes you heard me right! ...

Functions Of White Blood Cells And Immunization

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People can protect themselves from serious diseases by carrying out immunization i.e artificial immunization. 
 
But then, what's immunization?  
Immunization is the process of ingesting substances that is primed to make ones immune system  resistant to a specific pathogenic organisms or disease. Immunity created in the body is called natural immunization while the ones created by humans are called artificial immunity. 
 
Let's now know how artificial immunization is possible. 
 
We all know that the solid component of the blood known as the white blood cell carries out the important function of defending the body from pathogens or diseases. To make this more efficient,  the white blood cell is further categorized in two which include the phagocytes (that carry out phagocytosis, i.e ingestion of pathogens ) and the lymphocytes that secret substances called antibodies that function as follows in relation with the phagocytes. 
 
-Neutralization: the lymphocytes  neutralize the toxic produced by those pathogens or render them inactive. 
-Flocculation: The lymphocytes secret the disease causing organisms with antibodies that would cause them to clump together and then ingested by the phagocytes. 
 Clotting: during the process of clotting, the lymphocytes got attached to the mesh of fibrin that block the cut and thus prevent the entry of pathogenic organisms. 
 
Let's break down the lymphocytes a bit further. 
 
The lymphocytes are further classified into two principal groups and the null-group. 
B-lymphocytes: produce antibodies in the humoral immune response. 
 
T-lymphocytes: participate in the cell mediated immune response. 
 
The null-group contains the cytotoxic cells (natural killer cells) and  participates in the cell innate immune response. 
 
It's now important to note that a particular type of pathogen stimulates the production of a particular antibody. 
 
How immunization works: 
The artificial immunization is simply aimed at making or creating an awareness of a possible presence a disease and causing the lymphocytes to recognize them. 
This is done by ingesting a small dose of dead or weakened causal micro-organism of such disease into the body. 
This will quickly draw the attention of the lymphocytes and thus effect the production of a specific antibody that would kill the disease. 
 
So when these white blood cells are destroyed,  the body is left defenseless and thus exposed to any possible disease or pathogen. This exactly what AIDS does. 
 
It attacks and destroys the white blood cells. The diseased is left defenseless and different diseases invade the body. This will lead to the actual death of the person. What Aids does is only destroying the body immune,then the different diseases that invade the body lead to the death of such. 
 
Got any suggestion? 
Use the comment space. 
 </div>

Functions Of White Blood Cells And Immunization

People can protect themselves from serious diseases by carrying out immunization i.e artificial immunization. But then, what's immuni...

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