Most of our work is done on computers, and there is usually no escape from it. It is a visually intensive task and, unfortunately, our work pressure and lifestyles do not give us the opportunity to be kind to our eyes.

Some of the simple and valuable tips in handy,

Exercise Your Eyes

Our regular work hours should be infused with short breaks. During such breaks, a small and easy exercise can be done:
"First, blink your eyes several times. While you keep your eyes closed, roll your eyeballs both clockwise and anticlockwise and take a deep breath. Gradually open your eyes while releasing your breath. This exercise lasts for a minute and you can repeat it three times before getting back to work."
It serves as a good workout for the eyes.

Look Away

While working for long hours, look at distant objects either in your office or outside. looking at a distant object and then returning to your task helps your eyes focus better. Try taking such visual breaks for about 5 to 10 minutes every hour.

Palming

Sit straight at your workstation and rub your palms against each other till you feel them warm. The warmth of your palms helps soothe and relax tired eyes. Then, lightly cup your eyes with your palms and relax for 60 seconds. Count the seconds in your mind. Repeat this exercise 2 or 3 times whenever your eyes feel tired, or as often as you want.

Splash Water On Your Face

During breaks, splash water on your face while closing your eyes. This has an overall relaxing effect and helps you feel refreshed.

Take A Walk

After you are done with lunch, take a stroll outside your office for a few minutes. this will give your eyes a much-needed break and get them some fresh air.

Use Tea Bags

Keep 2 used tea bags in the refrigerator before you leave for work. Once you are home, place the tea bags on your eyes for a few minutes as you relax. This not only soothes tired eyes, but also reduces puffiness.

Drink Water

Drink plenty of water. It helps reduces puffiness. When a person is dehydrated, especially in air-conditioned office, the body starts storing water as a defence mechanism. This adds to puffiness around the eyes.

Eat Healthy

Incorporate Vitamins A, C and E on a daily basis. Eat Citrus fruits, green leafy veggies, tomatoes, spinach, poultry and dairy products. Pack a box of chopped carrots, cucumber and fresh and munch in-between meals at the office.

Know Your Contact Lenses

Ideally, a person who uses lenses should wear it for not more than 10-12 hours a day and occasionally for 14 hours a day. Never wear your contact lenses while swimming. The pool water houses various micro-organisms as there are several people using it. This may lead to fungal infections in the eyes. In addition the chlorine in the water can damage your contact lenses.
Lenses are like sponge, making them susceptible to attracting dirt.

Wear Anti-glare Glasses While Driving Or At Work

Anti-glare glasses are mainly used for focused light -- such as full beam car headlights -- and serve well for night driving. These can also be used while working on the computer.
Using a pair of anti-glare glasses while working on a computer can reduce the strain on the eyes to a certain extent. If you wear contact lenses, wear a pair of zero powered anti-glare glasses for the same purpose.

• Eat a Brain-Healthy Diet. A diet rich in omega-3 fatty acids (commonly found in fish), protein, antioxidants, fruits and vegetables and vitamin B; low in trans fats; and with an appropriate level of carbohydrates will help keep your brain healthy.
• Stay Mentally Active. Activities such as learning a new skill or language, working on crossword puzzles, taking classes, and learning how to dance can help challenge and maintain your mental functioning.
• Exercise Regularly. Exercising often can increase circulation, improve coordination, and help prevent conditions that increase the risk of dementia such as heart disease, stroke and diabetes.
• Stay Social. Spending time with friends, volunteering, and traveling can keep your mind active and healthy.
• Get Plenty of Sleep. Not getting enough sleep can have a negative impact on brain health.
• Manage Stress. Participating in yoga, spending time with friends, or doing other stress-relieving activities can help preserve your ability to remember and learn.
• Prevent Brain Injury. Wearing protective head gear and seat belts can help you avoid head injury, which has been associated with an increased risk of dementia.
• Control Other Health Conditions. Maintaining a healthy weight, exercising, eating a well-balanced and nutritious diet, and controlling stress can help reduce your risk of diseases that affect your brain, including diabetes, heart disease, high blood pressure and hypertension.
• Avoid Unhealthy Habits. Smoking, heavy drinking and use of recreational drugs can increase the risk of dementia and cognitive decline.
• Consider Your Genes. If your family history puts you at risk for developing dementia, work with your doctor to find ways to maintain your brain health to help avoid or slow the progression of cognitive decline.

Why do you need to breathe?

All the cells in your body require oxygen. Without it, they couldn't move, build, reproduce, and turn food into energy. In fact, without oxygen, they and you would die! How do you get oxygen? From breathing in air which your blood circulates to all parts of the body.


How do you breathe?

You breathe with the help of your diaphragm and other muscles in your chest and abdomen. These muscles literally change the space and pressure inside your body to accomodate breathing. When your diaphragm pulls down, it not only leaves more space for the lungs to expand but also lowers the internal air pressure. Outside, where the air pressure is greater, you suck in air in an inhale. The air then expands your lungs like a pair of balloons. When your diaphragm relaxes, the cavity inside your body gets smaller again. Your muscles squeeze your rib cage and your lungs begin to collapse as the air is pushed up and out your body in an exhale.


So, it all starts at the nose?

Yup. About 20 times a minute, you breathe in. When you do, you inhale air and pass it through your nasal passages where the air is filtered, heated, moistened and enters the back of the throat. Interestingly enough, it's the esophagus or foodpipe which is located at the back of the throat and the windpipe for air which is located at the front. When we eat, a flap -- the epiglottis -- flops down to cover the windpipe so that food doesn't go down the windpipe.


So -- back to breathing -- the air has a long journey to get to your lungs. It flows down through the windpipe, past the voice box or vocal cords, to where the lowermost ribs meet the center of your chest. There, your windpipe divides into two tubes which lead to the two lungs which fill most of your ribcage. Inside each of your sponge-like lungs, tubes, called bronchi, branch into even smaller tubes much like the branches of a tree. At the end of these tubes are millions of tiny bubbles or sacs called aleoli. Spread out flat, all the air sacs in the lungs of an adult would cover an area about the third of a tennis court.


What do these sacs do?

They help perform an incredible magic act. Your air sacs bring new oxygen from air you've breathed to your bloodstream. They exchange it for waste products, like carbon dioxide, which the cells in your body have made and can't use.


How does this exchange work?

With the help of the red blood cells in your bloodstream. Your red blood cells are like box cars on train tracks. They show up at the sacs at just the right time, ready to trade in old carbon dioxide that your body's cells have made for some new oxygen you've just breathed in. In the process, these red blood cells turn from purple to that beautiful red color as they start carrying the oxygen to all the cells in your body.


But what happens to the carbon dioxide?

It goes through the lungs, back up your windpipe and out with every exhale. It's a remarkable feat, this chemical exchange and breathing in and out. You don't have to tell your lungs to keep working. Your brain does it automatically for you.


Factoids

Your lungs contain almost 1500 miles of airways and over 300 million alveoli.

Every minute you breathe in 13 pints of air.

Plants are our partners in breathing. We breathe in air, use the oxygen in it, and release carbon dioxide. Plants take in carbon dioxide and release oxygen. Thank goodness!

People tend to get more colds in the winter because we're indoors more often and in close proximity to other people. When people sneeze, cough and even breathe -- germs go flying!

Gastritis is an inflammation of the lining of the stomach. It causes severe discomfort to the patient suffering from this problem is also very commonly called “Heart Burn”. The most common symptom is abdominal upset or pain in the abdomen. There are many other symptoms other than abdominal pain. Indigestion, Abdominal bloating, Nausea and vomiting, Feeling of fullness, Burning in the upper abdomen.


PREVENT THESE CASUSES

1. Indigestion: Caused due to either excessive intake of food when compared to the regular levels or having food that the body is not used to. Indigestion can also be attributed to consumption of food at irregular timings. In this case the body is not prepared to digest food when ever food is partaken.

2. Excessive alcohol consumption which damages the liver and digestive system.

3. Prolonged use of anti- inflammatory drugs such as Ibruofen. Intake of such drugs in excess can damage the digestive system.

4. Indigestion can also occur in people who have undergone weight loss treatments which suggest very aggressive diet control schedules.

5. Weight loss surgical treatments can result in the banding for reconstruction of the digestive tract and damage the digestive system.

6. Stress has been one of the main reasons attributed to indigestion. It could be due physical stress caused due to over straining of the bones and muscles. Mental stress also can impact the functioning of the digestive system.

7. An irregular eating pattern which includes the type of food taken and the timing of the food taken.

8. Bacterial infections are very common reason for having a digestive system problem. Bad bacteria in the intestines can disturb the digestive track and cause indigestion.


Here are some simple steps that work on reducing gastritis :-

1. Too many different foods should not be mixed at the same meal.

2. Meals should be taken at least two hours before going to bed at night.

3. At least 8 to 10 glasses of water should be partaken every day.

4. And above all, haste should be avoided while eating and food should be served in a pleasing and relaxed atmosphere.

5. Practicing good physical exercise like walking for older people, jogging for middle aged people and swimming for younger people on a regular basis.

6. Practicing good mental exercises like pranayama which can relax the mind and body.

Depression drains your energy, hope, and drive, making it difficult to do what you need to feel better. But while overcoming depression isn’t quick or easy, it’s far from impossible. You can’t beat it through sheer willpower, but you do have some control —even if your depression is severe and stubbornly persistent.


Ways to challenge negative thinking:

Think outside yourself. Ask yourself if you ’d say what you’re thinking about yourself to someone else. If not, stop being so hard on yourself. Think about less harsh statements that offer more realistic descriptions.

Keep a “negative thought log”. Whenever you experience a negative thought, jot down the thought and what triggered it in a notebook. Review your log when you ’re in a good mood. Consider if the negativity was truly warranted. For a second opinion, you can also ask a friend or therapist to go over your log with you.

Replace negatives with positives. Review your negative thought log. Then, for each negative thought, write down something positive. For instance, “My boss hates me. She gave me this difficult report to complete ” could be replaced with, “My boss must have a lot of faith in me to give me so much responsibility. ”Socialize with positive people. Notice how people who always look on the bright side deal with challenges, even minor ones, like not being able to find a parking space. Then consider how you would react in the same situation. Even if you have to pretend, try to adopt their optimism and persistence in the face of difficulty.

Hepetitis B is the most common serious liver infection in the world. Worldwide, about 350 million people are chronic carriers of HBV, of whom, more than 250,000 die from liver- related disease each year.
Chronic hepatitis B also can lead to a type of liver cancer known as hepatocellular carcinoma. Any of these conditions can be fatal. About 15-25 percent of people with chronic hepatitis B die of liver disease.


Hepatitis B Prevention
There is a vaccine against the hepatitis B virus (Engerix-B, Recombivax HB ). It is safe and works well to prevent the disease. A total of 3 doses of the vaccine are given over several months.

•This vaccine has successfully prevented infection in people exposed to the virus.

• The vaccine is recommended for all children younger than 19 years. It can be given as part of their normal vaccination series.

The following groups should be vaccinated for hepatitis B:

•All children younger than 18 years, including newborns--especially those born to mothers who are infected with HBV

• All health care and public safety workers who may be exposed to blood

• People who have hemophilia or other blood clotting disorders and receive transfusions of human clotting factors

• People who require hemodialysis for kidney disease

• Travelers to countries where HBV infection is common -This includes most areas of Africa, Southeast Asia, China and central Asia, Eastern Europe, the Middle East, the Pacific Islands, and the Amazon River basin of South America.

• People who are in prison

•People who live in residential facilities for developmentally disabled persons

• People who inject illegal drugs

•People with chronic liver disease such as hepatitis C

•People who have multiple sex partners or have ever had a sexually transmitted disease

• Men who have sex with men Hepatitis B immune globulin (BayHep B, Nabi-HB) is given along with the hepatitis B vaccine to unvaccinated people who have been exposed to hepatitis B.

•These include close contacts of people with HBV infection, health care workers who are exposed to HBV-contaminated blood, and infants born to mothers infected with HBV.

• It also includes people who have finished only part of the 3-shot vaccination series.

• Giving the immune globulin and the vaccine together in these situations prevents transmission of the disease in 80-90 percent of cases.

Other ways to protect yourself from HBV infection:

•If you are sexually active, practice safe sex. Correct use of latex condoms can help prevent transmission of HBV, but even when used correctly, condoms are not 100% effective at preventing transmission. Men who have sex with men should be vaccinated against both hepatitis A and hepatitis B.

• If you inject drugs, don't share needles or other equipment.

• Don't share anything that might have blood on it, such as a razor or toothbrush.

• Think about the health risks if you are planning to get a tattoo or body piercing. You can become infected if the artist or piercer does not sterilize needles and equipment, use disposable gloves, or wash hands properly.

•Health care workers should follow standard precautions and handle needles and sharps safely.

• If you are pregnant or think you might be pregnant, tell your health care provider if you have any of the risk factors for HBV infection.

Sleepwalking is most common in children, occurs at deepest levels, and is thought to be caused by a partial arousal from deep sleep. While the child's brainwaves are those of deep sleep, the sleepwalker moves as though awake.The episodes are typically brief —less than ten minutes— and usually occur during the first three hours of sleep. The sleepwalker usually has no recollection of the event in the morning.

How common is it?

A balanced diet comprising of healthy and diverse foods is key to promoting good health. After all, we are what we eat -Research continues to prove that eating healthy food promotes good health and unhealthy food habits lead to a diseased body. Foods contain vital nutrients that aid our body’s metabolic function. However, a lack of consumption of these nutrients or feeding upon the wrong kinds of food leads to an accumulation of toxins within the body, resulting in chronic diseases in the long run.
A nutritious diet while ensuring overall well being, helps to maintain a healthy Body Mass Index (BMI), reduces the risk of several debilitating diseases like cancer, cardiovascular ailments, diabetes, osteoporosis and stroke.
Thus a nutritious diet is important in the prevention and cure of various diseases. Healthy Food Groups Since no single food group can nourish the body with all the vital ingredients it requires, it is important that we consume a variety of healthy foods to derive the nutrition our body needs. There are five main food groups, they are:
• Fruits
• Vegetables
• Cereals and Pulses
• Dairy
• Poultry, Fish and Meat products

A healthy balanced diet of these five food groups ensures essential vitamins, minerals and dietary fiber. The food group serving size will depend upon various factors like age, activity level, body size and gender. It is also important that one eat a variety of foods from within and across the food groups. As some foods from within a food group provide more nutrients than others. This will ensure that one gets the maximum recommended nutrition from the food group; besides the food variety will make for an interesting meal.

Milk is an excellent source of complete protein (containing all 9 essential amino acids which are required to meet our physiological needs), one of the primary sources of bone-building calcium for adults and also a treasure-trove of vitamins (especially D and K). It Prevent Gastritis & Induce sound sleep.

The health benefits of honey and milk include skin care and stamina development. This article elaborates the health benefits of milk and honey taken together.

Skin Care: Both honey and milk posses antimicrobial and cleansing properties. These properties are enhanced when the two are taken together. Numerous cleansers are prepared using milk and honey as the mixture gives a glowing skin. One can also enjoy a milk and honey bath, by mixing them in equal quantities. The combination is used in various spas throughout the world.

Stamina: A glass of milk and honey daily in the morning is known to improve the stamina of people. While milk contains proteins, honey contains the necessary carbohydrates required for effective metabolism. Milk and honey provides strength to all including children and old men and women.

Anti Aging: Milk and honey combination acts not only on the skin but also on the entire body by making it agile and youthful. People in many ancient civilizations including Greeks, Romans, Egyptians and Indians drank milk and honey to preserve their youth. Since milk and honey ensure long life, the combination was known as the elixir of life.

Anti Bacterial: Research has shown than milk and honey have higher activity on staphylococcus bacteria than milk or honey taken alone. It is also believed that honey added to warm milk cures constipation, flatulence and intestine disorders. It is also good for treating respiratory disorders such as cold and cough. The benefits of honey and milk to the human body are so enormous that the phrase “land of milk and honey” meaning “a place which has plenty” is commonly used.
Jerusalem is referred to as the land of milk and honey in the Old Testament.

Maintaining good oral hygiene is one of the most important things you can do for your teeth and gums. Healthy teeth not only enable you to look and feel good, they make it possible to eat and speak properly. Good oral health is important to your overall well-being.
Daily preventive care, including proper brushing and flossing, will help stop problems before they develop and is much less painful, expensive, and worrisome than treating conditions that have been allowed to progress. In between regular visits to the dentist, there are simple steps that each of us can take to greatly decrease the risk of developing tooth decay, gum disease and other dental problems. These include:

•Brushing thoroughly twice a day and flossing daily.

• Eating a balanced diet and limiting snacks between meals.

• Using dental products that contain fluoride, including toothpaste.

• Rinsing with a fluoride mouthrinse if your dentist tells you to.

• Making sure that your children under 12 drink fluoridated water or take a fluoride supplement if they live in a non- luoridated area.

Every second, blood travels around our body through a series of pipes called arteries or veins. Blood carries oxygen and other vital chemicals around the body to all the organs and simultaneously collects waste and other toxins for eventual treatment and disposal. So, if one of our arteries/veins becomes blocked, causing a stoppage in the blood flow, our organs stop working and we collapse.

For a healthy heart, follow these simple steps.

First, to find out where you stand, I suggest you visit your local health clinic for a cholesterol test. This is a quick test (usually done by a nurse) to check the level of fat in your blood, and you should have it done at least once every two years.

Next, If this post has shown you that your lifestyle needs changing, then change it! Don't just ignore the situation and hope it will go away: it won't! So quit smoking, get down to a normal weight, start exercising regularly; don't take life too seriously and start eating properly.

Next, before you start a Healthy- Heart Diet, get organised! For example, in order to eat more fruit and less fat, I strongly advise you to invest in a juicer to make your own fruit juice, and a good non-stick frying pan to help you fry without fat.

And make a list of good foods to keep in the house. Remember: the worst mistake you can make is to run out of good things to eat!

Kidneys and liver are extremely important organs, so you want to keep them as healthy as possible. There are several steps you can take to prevent damage to these vital organs.


Step need to Follow

1. Stay properly hydrated by drinking water. If you exercise a lot, you may also want to consume a few sports drinks to replace electrolytes lost via sweating.

2. Lose Weight

3. If you are at risk for diabetes due to family history or lifestyle, get evaluated for the condition periodically & seek treatment if the evaluation results suggest you are having problems with your blood sugar levels.

4. If you are a diabetic, properly control your blood sugar levels.

5. Do not consume alcoholic beverages in excess. If you already have liver damage, consult with your doctor to determine if you should consume alcohol at all.

6. Avoid recreational drugs, especially IV drugs.

7. Maintain healthy eating habits, exercise regularly and get enough sleep.

8. Do Pranayam (especially Kapalbhati) for 10 minutes daily.

9. Treat infections properly by routine examination of urine & Liver function.

10. Avoid medicines like pain killers frequently.

Frustration, depression, fear, anxiety, insecurity, loneliness, vacuum, dejection, self pity, sadness are some of the hallmarks of old age. This is because

1. With aging there is increasing restriction on the kind of accustomed enjoyments (e.g. sexual); and this can lead to frustration or depression.

2. The realization of the increased chances of death; (due to observation of the deaths of the contemporaries); causes alarm, concern, anxiety and excessive fear of death, diseases and debility.

3. Due to lack of job after retirement or physical inability there is always a sense of insecurity.

4. Lack of the children's company due to their being increasingly independent gives a feeling of unwantedness and loneliness, especially due to children going abroad or away from home for their jobs.

5. Since most of the people of younger age groups; have their own pre-occupations we the elderly are left out.

6. Due to generation gap; the ideas, choice, preferences and other areas of interests differ and hence the elderly are cut off from younger generation. This distance gradually increases with advancing age and leads to vacuum, dejection, self pity and sadness. Thus overall we tend to become increasingly melancholic in old age.

It makes you feel more happy, have more positive energy & attract more positive people in your life.Positive attitude also allows you to put thing in a better perspective. For example, when you're faced with problem, you will tend to look for a solution instead of trying to find faults and blame others.It can also give you a better health as positive energy will lower your stress level.


STEPS

1. If you want to develop a positive attitude, start by becoming more aware of your mind patterns. Be an observer of your mind. When you become an observer, you're in control and you'll be able to notice what your mind says (both positive and negative). Therefore, when you notice your mind saying something negative, you can intercept it and replace it with positive thought.

2. Live Life NOW! Learn to live fully in your present moment. Don't cling on your past or wish you could have this or that. Appreciate what you already have NOW. Express gratitude for everything you have now. HERE and NOW are your life! Once you have accepted that, you can become more positive and appreciative of life. You will do and live your best in your present moment. Only then, you can move forward in life with positive attitude.

3. Associate more with positive people. I'm sure you have heard this saying: "Birds of the same feather flock together." If you flock together with negative people, you will become negative. On the other hand, if you associate yourself with more positive people, they can also influence your characters and attitude. You will become more positive as well.

4. Learn to give compliment to others. You don't need to do this excessively. Just do it in a natural way by focusing on the positive side of other people. A few kind words spoken to another person can really make his or her day. Doing so will make you more likable as well.

5. SMILE and say THANK YOU more. Wherever you are and whatever you do, look for opportunity to offer sincere appreciation to your friends, family members, peers, team members, bosses or any other people you interact with everyday. Smiling and saying thank you more often not only can make you feel good but also cause those around you to become more positive. Develop your positive attitude daily and make it become second nature to you. This will give you more happiness in life.

Have you known that one of the important thing for our body is SALT.



The Salt that we take in our food is a vital substance for the survival of all living creatures, particularly humans.

Water(H2O) and salt(NaCl) regulate the water content of the body. Water itself regulates the water content of the interior of the cell by working its way into all of the cells it reaches to cleanse and extract the toxic wastes. Salt forces some water to stay outside the cells.

The other way to explain this is that there are two oceans of water in the body; one ocean is held inside the cells of the body, and the other ocean is held outside the cells and Good health depends on a most delicate balance between the volume of these oceans, and this balance is achieved by SALT.

Salt is also crucial for the extraction of excess acidity from the cells in the body, particularly the brain cells. Salt is very important for the generation of hydroelectric energy in the cells in the body.

Do you know, Common Table Salt you buy from your grocery store is completely Bleached and Leached of all its minerals. Common Table Salt also includes additives including aluminum silicate (to make it free flowing), dextrose, bleaching elements, and other chemicals, making it POISONOUS for the body?

SALT IS VITAL FOR THE
HUMAN BODY: BUT THE
RIGHT TYPE!

The WRONG type of salt is common table salt you get, its often
labeled as “ free flowing” or “refined salt” or “iodized salt”. The RIGHT type of salt is Natural salt that is unrefined crystal Rock salt.

You can find this at any health shop near you. In India most people call it “Sendha Namak” it is very light pinkish to white in color, and powdered from the crystal, make sure you check it says unrefined.

Crystal rock salt contains 84 of the 92 trace minerals known to man, and no other natural or man-made salt has this many minerals. In addition, the salt contains the minerals in the same proportions as the human body does, as well as the vital minerals such as calcium and magnesium.

All of these elements are crucial for good health, and keeping you free from dis- ease.

A small shift of changing the Salt in your home will make the biggest difference in the wellbeing of you and your loved ones.

Please Note: An adult requires no more than 6gms (approx 1teaspoon) per day.

1. Use Repetition - Repeating to yourself the thing you want to remember may be simple, but it really does work. Repeat a phone number several times, for example, and you should remember it for a short while.
This works even better if you "sing" it in your mind to engage other parts of the brain. To remember things long-term, repeat or review them several times upon learning them, then the next day, the day after that,
the the next week and the week after that.

2. Write It Down - Let the paper remember for you. The point is to
have use of the information later, and if that's more easily done by way of an "external memory
device" like pen and paper, why not take advantage of these tools?
Also, writing things down is another way to more strongly "fix" something in our minds.

3. Clear Your Mind - Sometimes to recall something you just need to relax and empty your mind of all the other stuff going on in there.
Take three deep and slow breaths through your nose and relax your muscles. Pay attention to the air
moving in and out of your nostrils. Afterward return to
whatever it is you need to recall or work on.

4. Feed Your Brain - This means feeding your body of course. Your brain needs a lot of energy, and will generally function better if you eat some good proteins and
complex carbohydrates. Trail mix, with nuts and dried fruit works
well for some. Fish has been shown to immediately speed up
brain function, as well as improve memory and other brain functions long-term improvement if eaten regularly. Also, the
distraction caused by hunger can interfere with your concentration and ability to recall things.
5. Drink Enough Fluids - Dehydration is not always recognized, and can both distract
you in ways that get in the way of clear thinking and memory, as well as more directly impacting the functioning of the brain. You can experiment to see if this is happening in your case. Just drink
a glass of water and note whether your mind seems to work better.

6. Exercise - Physical exercise has been shown to improve brain function both immediately (after
ten minutes on a treadmill, for example), and long term. The short-term effect is because of the immediate increase in blood flow
and therefore oxygen to the brain. The long-term improvement
in memory and other brain functions that come from regular
exercise may also be due to the physical improvement of the brain and body that comes from this
repeated increase in blood flow and oxygen.

7. Learn A Mnemonic Technique - There are many good memory
techniques for remembering names, numbers, lists of things and more. A simple list of items
can be "fixed" in your memory, for example, by linking them together in a crazy story that you visualize.
You can find some of these techniques (as well as other memory tips) covered here on the website and in the Brainpower Newsletter.

8. Imagine The Use - If you think about how you will use information, you're more likely to remember it. For example if after learning a new algorithm in a math class you imagine using it during a test, you'll probably remember it better - particularly when taking a test. Imagine
meeting someone again in the future and using his name, and you'll likely recall it when that does happen.

9. Avoid Toxins - Smoking is the obvious one here. Although it may actually help a person concentrate in the short-term, the damage smoking does may later hurt brain function in general,
including memory. Many prescription drugs and of course
illegal drugs can also have a negative effect.

10. Reduce Stress - When you're stressed, your body releases cortisol, which at high levels interferes with the part of the brain that handles recent
memories. Chronic stress has even been shown to cause brain shrinkage. Meditate or do other self-work to learn how not to be stressed out. This may be the most important of these tips on how to improve memory, good not only for the brain but for your whole body and life experience.

In our body there is a constant balance between acid and base. The following
equations are to be considered:

1) Henderson Hasselbalch equation:
pH = 6.2 + log
[HCO3-]/ 0.03 PCO2
where 6.2 is the pKa (negative logarithm of the acid dissociation constant) for carbonic acid
(H2CO3) and 0.03, the factor which relates PCO2 to the amount of CO2 dissolved in plasma.

2) Kassirer-Bleich equation

A drop or rise in PCO2 will result in a drop or rise in [H+] respectively.

[HCO3-] on the other hand is inversely related to H+ concentration whereby a drop in bicarbonate levels result in an increase in H+ concentration while a rise in bicarbonate levels result in a reduction in H+ concentration.

This buffer system is of physiologic importance because both the pulmonary and renal mechanisms for regulating pH work by adjusting this ratio.

The PCO2 can be modified by changes in alveolar ventilation, while plasma [HCO3-] can be altered by regulating its generation and excretion by the kidneys.

Definitions :- An acid base disorder is a change in the normal value of extracellular pH that may result
when renal or respiratory function is abnormal or when an
acid or base load overwhelms excretory capacity.
Normal acid base values
pH 7.35- 7.45
PCO2 36- 44
HCO3 22-26


Acid base status is defined in terms of the plasma pH.

Acidemia - decrease in the blood pH below normal range of 7.35 -7.45

Alkalemia - Elevation in blood pH above the normal range of 7.35 – 7.45

Clinical disturbances of acid base metabolism classically are defined in terms of the HCO3- /CO2 buffer system.

Acidosis – process that increases [H+] by increasing PCO2 or by
reducing [HCO3-]

Alkalosis – process that reduces [H+] by reducing PCO2 or by
increasing [HCO3-] lightbulb It is important to note that
though acidosis and alkalosis usually leads to acidemia and alkalemia respectively, the exception occurs when there is a mixed acid base disorder. In
that situation, multiple acid base processes coexisting may lead to a normal pH or a mixed picture.

This will be discussed in more detail later.
Since PCO2 is regulated by respiration, abnormalities that primarily alter the PCO2 are referred to as respiratory acidosis (high PCO2) and
respiratory alkalosis (low PCO2).

In contrast, [HCO3-] is regulated primarily by renal processes.
Abnormalities that primarily alter the [HCO3-] are referred to as metabolic acidosis (low [HCO3-])
and metabolic alkalosis (high [HCO3-]).

Simple acid base disorders : Disorders that are either metabolic or respiratory.

Mixed acid base disoders: More than one acid base disturbance present. pH may be normal or
abnormal.

The intracellular and extracellular compartments are separated from one another by the plasma
membrane of the cells. The extracellular
compartments (interstitial/
plasma/lymph) are separated by
a layer of endothelial cells
surrounded by a basement
membrane; the capillaries. To
cross from the plasma to the cells
or vice versa, substances must
either cross both membranes of
the endothelial cells or travel
between the cells and then cross
the basement membrane.

Capillaries come in three main types distinguished largely on the permeability of their walls.

1) Continuous capillaries have a close connection between adjacent cells and will permit only small molecules < 10nm in diameter to cross. Continuous capillaries surround muscle, skin lungs, adipose tissue CNS, retina and mammary glands.

2) Fenestrated capillaries contain
'windows' that offer easy passage to larger molecules(10-100nm) and are found around the kidneys, pancreas,
gallbladder and intestine.

3) Discontinuous have wide gaps between the cells and will allow practically anything (even cells)
across. Discontinuous capillaries surround the liver, spleen,
ovaries and some endocrine glands.

Capillaries act rather like a leaky hosepipe; although the bulk of
the fluid continues along the pipe, the pressure forces some
out of the walls. The fluid and soluble contents of plasma small enough to cross the capillary wall
circulate into the interstitial fluid at the high pressure arterial end of the capillary bed and returns
to the capillary, bringing with it
small soluble waste products from the cells, at the low
pressure venous end of the capillary bed (Oxygen and CO2
being lipid soluble, diffuse from the plasma across the capillaries and to and from the cells as necessary).

Hydrostatic (blood)
pressure is not the only force acting to cause fluid movement
in and out of the capillaries. The plasma proteins that cannot
cross the capillary walls exert an osmotic pressure to draw water back into the capillaries which
outweighs the hydrostatic pressure at the venous end of
the capillaries. The balance of hydrostatic and osmotic forces causing movement out and into the capillaries are known as Starling forces.

Cell is a structural and functional unit of life, as being
a free-floating and self-replicating
molecule, it would appear to offer
survival advantages, after all there are lots of cells around now and very few non-cellular life forms. Although it might
be argued that bacteria represent the most successful
cellular lifeform, because there
are more of them then anything
else, being a multicellular
organism does seem to have some things going for it. The
simplest possible multicellular
organism is a sponge. A sponge
is a collection of identical cells
that exist as a colony. It is
possible to disperse a sponge
through a sieve, if you leave the
pieces in a bucket for a few days
they will reform back into a
colony with apparently no ill
effects. However, the real
advantages to being multicellular
aren't apparent until component
cells start to show specialisation.
A flatworm is a good example of
the next stage of development.
Flatworms do not have digestive
or circulatory systems; most of
the animal is a flattened cylinder
of cells. Nevertheless, the cells on
the outside of the cylinder are
specialised and act to hold the
animal together, to protect the
inner layers and to absorb food
from the environment. In short
the outer layer of the flatworm
creates a comfortable internal
environment for all the other cells
to live in. Homeostasis may now
occur at both the level of the
single cell and at the level of the
whole organism. One of the main
disadvantages of being a
flatworm is that you have to be
flat to allow oxygen to diffuse
into the innermost layers of cells
(and also to let CO2 diffuse out).
Any arrangement other than
being flat puts the innermost
cells to far away from the outside
to survive. Everything more
advanced than a flatworm has
discovered the way around this
is to have a circulatory system to
reach the parts that diffusion
cannot reach. Once past this
hurdle, all sorts of specialisation
amongst the cells that comprise
an organism become possible.
The digestive system is a way of
extending the surface area for
digestion whilst simultaneously
protecting it by internalising it,
thus the same cells don't have to
try and combine protective and
digestive functions. The lungs are
essentially the result of the same
principle applied to the problem
of gaseous exchange. The liver,
the brain, the muscles etc. etc.
etc. have all evolved to play their
own part in the homeostasis of
the whole organism. The part of
the body that has charge of
maintaining the ionic
composition of the organism, a
task analogous to that of the
plasma membrane in a single cell,
is the kidney.
In the human body (for example)
there are several major fluid
compartments each of which is
subject to homeostatic
regulation.
The largest compartment is the
intracellular compartment. Any
fluid not contained inside a cell
therefore comprises the
extracellular compartment. The
extracellular compartment may
be divided into an interstitial
compartment (means literally 'in
the spaces', in this case, the
spaces between the cells) and a
circulating compartment (the
blood plasma and the lymph
fluid). A 70 kg man (the figures
are slightly different for women)
contains about 40-45 litres of
water.


Total 45 litre

Intracellular 27

Extracellular 18
interstitial 13

plasma 3.5

lymph 1.5

If all the water were removed
from a human body some 30 kg
of assorted salts would remain.
Despite the impression given by
Start Trek or Red Dwarf where
dried people are represented by
a tiny pile of salt crystals, 30 kg is
a lot of material. Imagine 15 bags
of sugar poured all over the floor.

The normal composition of the
major body fluid compartments
is approximately as follows
(mmol/l, except Ca2+)

Constituent (1st)
Plasma (2nd)
Interstitial fluid (3rd)
Intracellular fluid (4th)

Na+ 142 139 14

K+ 4.2 4 140

Ca2+ 1.3 1.2 0

Mg2+ 0.8 0.7 20

Cl- 108 108 4

HCO3- 24 28.3 10

Protein 1.2 0.2 4

Glucose 5.6 5.6 absent

Amino acid 2 2 8

Urea 4 4 4

* The ionic Ca2+(free) is very low
inside cells, total calcium may be
much higher (1-2 mmol/l)

In the above overall osmolarity of all three
compartments is identical at
about 300 mOsmol/l.

You'll never sail among the Islands of Langerhans or drift lazily down the aqueduct of Sylvius. And don't expect to stroll along the banks of Hunter's Canal, or watch the sun go down behind McBurney's point, explore the Fissure of Rolando or ride through the Tunnel of Corti. You'll never trundle the Bundle of Vicq d' Azyr, or pillow your head no Passavant's Cushion, or vacation in Wernicke's Centre. Nor will you wall under the Palmar Arch, or Loop the Loop of Henle. And you may travel the whole world over and never gaze down upon Pacchionian depression or stand in the shadow of the Pyramids of Malpighi. Because - they are parts of the human body!!!!

Iron is critical to a number of
synthetic and enzymatic
processes. Most of the body iron
is part of the hemoglobin
molecule where iron serves a key
role in oxygen transport. Iron is
recycled and thus conserved by
the body. Daily intake ( 1 mg ) s
balanced against small daily
losses (1 mg ).
The amounts shown in the Fe
Cycle Card are in mg of iron lost
or gained per day. They were
derived in the following manner.
The average blood volume in a
70 kg man is 5,000 ml.
There are 150 grams of
hemoglobin in each liter of
blood, therefore there are 750 g
of hemoglobin in the body.
Each gram of hemoglobin
contains approximately 3.3 mg of
iron or 2475 mg of iron in the
body.
Dividing the 2475 mg total by the
120 day average RBC lifespan
results in the iron needed per
day or 20.6 mg iron/day.
Hemoglobin Fe 2200 mg
Ferritin & Hemosiderin 1000 mg
Myoglobin Fe 300 mg
Other Fe (cytochromes; enzymes) 100 mg
Total Body Iron 3600 mg
An average adult in the U.S. on a
2,500 calorie diet ( 6 mg of
iron/1,000 kcal) ingests 15 mg of
iron daily. Only 5-10 % or about
1.0 mg of dietary iron is
absorbed as ferrous iron (Fe++),
mainly in the duodenum and
upper jejunum where the pH is
low. The mucosal cells oxidize the
ferrous iron to ferric iron
, which is then
complexed with apoferritin to
form ferritin. Some of the ferritin
is transported out of the mucosal
cell into the plasma bound to
transferrin. Thus bound, iron can
be transported to the bone
marrow or iron storage sites
where it is stored as either
ferritin or hemosiderin.

Most cells have transferrin
receptors (CD 71) to which iron
ladden transferrin binds. The
receptor-transferrin-iron
complex is then incorporated
into the cytosol by endocytosis.
In red cells the endocytotic
vacuole fuses with a lysozyme,
where at an acid pH the iron (Fe+
+) is released from transferrin
and transported to mitochondria
where it is incorporated into
heme, the ferrous iron complex
of protoporphyrin IX.
Fe
Although iron is utilized in
virtually all cells, the bulk of body
iron is found in erythrocytes with
lesser amounts in myoglobin.
Large amounts of iron are
required during growth periods
in infant, childhood and teenage
years.
Transferrin carries iron to the
bone marrow where it is
accepted into RBCs via a
transferrin receptor (CD71) and
incorporated into heme for use
in hemoglobin.
Not all erythrocytes develop and
mature successfully. Some die in
the marrow and their iron is
salvaged by macrophages. This
failure to mature resulting in
death in the marrow is known as
ineffective erythropoiesis.

Normally only small amounts of
iron are lost daily as hair, skin,
urinary bladder,and
gastrointestinal cells are shed.
This amount can easily be
replaced by dietary intake.
With bleeding, larger amounts of
iron can be lost. The most
common normal blood losses are
due to menstruation and
pregnancy.

Glucose is by far the most
common carbohydrate and classified as a monosaccharide,
an aldose, a hexose, and is a reducing sugar. It is also known
as dextrose, because it is dextrorotatory (meaning that as
an optical isomer is rotates plane
polarized light to the right and also an origin for the D
designation. Glucose is also called blood sugar as it circulates in the blood at a
concentration of 65-110 mg/mL of blood.
Glucose is initially synthesized by chlorophyll in plants using carbon dioxide from the air and
sunlight as an energy source. Glucose is further converted to
starch for storage.

Ring Structure for Glucose:

Up until now we have been
presenting the structure of
glucose as a chain. In reality, an
aqueous sugar solution contains
only 0.02% of the glucose in the
chain form, the majority of the
structure is in the cyclic chair
form.
Since carbohydrates contain both
alcohol and aldehyde or ketone
functional groups, the straight-
chain form is easily converted
into the chair form - hemiacetal
ring structure. Due to the
tetrahedral geometry of carbons
that ultimately make a 6
membered stable ring , the -OH
on carbon #5 is converted into
the ether linkage to close the
ring with carbon #1. This makes
a 6 member ring - five carbons
and one oxygen.
Steps in the ring closure
(hemiacetal synthesis):
1. The electrons on the alcohol
oxygen are used to bond the
carbon #1 to make an ether (red
oxygen atom).
2. The hydrogen (green) is
transferred to the carbonyl
oxygen (green) to make a new
alcohol group (green).
The chair structures are always
written with the orientation
depicted on the left to avoid
confusion.
Hemiacetal Functional Group:
Carbon # 1 is now called the
anomeric carbon and is the
center of a hemiacetal functional
group. A carbon that has both an
ether oxygen and an alcohol
group is a hemiacetal.

Glucose in the Chair Structures:

The position of the -OH group on
the anomeric carbon (#1) is an important distinction for carbohydrate chemistry. The Beta position is defined as
the -OH being on the same side of the ring as the C # 6. In the
chair structure this results in a horizontal projection.
The Alpha position is defined as the -OH being on the opposite
side of the ring as the C # 6. In the chair structure this results in a downward projection.
The alpha and beta label is not
applied to any other carbon -
only the anomeric carbon, in this
case # 1.

As the heart undergoes
depolarization and
repolarization, electrical currents
spread throughout the body
because the body acts as a
volume conductor. The electrical
currents generated by the heart
are commonly measured by an
array of electrodes placed on the
body surface and the resulting
tracing is called an
electrocardiogram (ECG, or EKG).
By convention, electrodes are
placed on each arm and leg, and
six electrodes are placed at
defined locations on the chest.
These electrode leads are
connected to a device that
measures potential differences
between selected electrodes to
produce thecharacteristic ECG
tracings.
Some of the ECG leads are bipolar
leads (e.g., standard limb leads)
that utilize a single positive and a
single negative electrode
between which electrical
potentials are measured.
Unipolar leads (augmented leads
and chest leads) have a single
positive recording electrode and
utilize a combination of the other
electrodes to serve as a
composite negative electrode.
Normally, when an ECG is
recorded, all leads are recorded
simultaneously, giving rise to
what is called a 12-lead ECG.

General Description
As the heart undergoes
depolarization and
repolarization , the electrical
currents that are generated
spread not only within the heart,
but also throughout the body.
This electrical activity generated
by the heart can be measured by
an array of electrodes placed on
the body surface. The recorded
tracing is called an
electrocardiogram (ECG, or EKG).
A "typical" ECG tracing is shown
to the right. The different waves
that comprise the ECG represent
the sequence of depolarization
and repolarization of the atria
and ventricles. The ECG is
recorded at a speed of 25 mm/
sec, and the voltages are
calibrated so that 1 mV = 10 mm
in the vertical direction.
Therefore, each small 1-mm
square represents 0.04 sec (40
msec) in time and 0.1 mV in
voltage. Because the recording
speed is standardized, one can
calculate the heart rate from the
intervals between different
waves.
P wave
The P wave represents the wave
of depolarization that spreads
from the SA node throughout the
atria, and is usually 0.08 to 0.1
seconds (80-100 ms) in
duration. The brief isoelectric
(zero voltage) period after the P
wave represents the time in
which the impulse is traveling
within the AV node (where the
conduction velocity is greatly
retarded) and the bundle of
His. Atrial rate can be calculated
by determining the time interval
between P waves. Click here to
see how atrial rate is calculated.
The period of time from the
onset of the P wave to the
beginning of the QRS complex is
termed the P-R interval, which
normally ranges from 0.12 to
0.20 seconds in duration. This
interval represents the time
between the onset of atrial
depolarization and the onset of
ventricular depolarization. If the
P-R interval is >0.2 sec, there is
an AV conduction block, which is
also termed a first-degree heart
block if the impulse is still able to
be conducted into the ventricles.
QRS complex
The QRS complex represents
ventricular
depolarization. Ventricular rate
can be calculated by determining
the time interval between QRS
complexes. Click here to see how
ventricular rate is calculated.
The duration of the QRS complex
is normally 0.06 to 0.1 seconds.
This relatively short duration
indicates that ventricular
depolarization normally occurs
very rapidly. If the QRS complex
is prolonged (> 0.1 sec),
conduction is impaired within
the ventricles. This can occur
with bundle branch blocks or
whenever a ventricular foci
(abnormal pacemaker site)
becomes the pacemaker driving
the ventricle. Such an ectopic foci
nearly always results in impulses
being conducted over slower
pathways within the heart,
thereby increasing the time for
depolarization and the duration
of the QRS complex.
The shape of the QRS complex in
the above figure is idealized. In
fact, the shape changes
depending on which recording
electrodes are being used. The
shape will also change when
there is abnormal conduction of
electrical impulses within the
ventricles. The figure to the right
summarizes the nomenclature
used to define the different
components of the QRS complex.
ST segment
The isoelectric period (ST
segment) following the QRS is
the time at which the entire
ventricle is depolarized and
roughly corresponds to the
plateau phase of the ventricular
action potential. The ST segment
is important in the diagnosis of
ventricular ischemia or hypoxia
because under those conditions,
the ST segment can become
either depressed or elevated.
T wave
The T wave represents
ventricular repolarization and is
longer in duration than
depolarization (i.e., conduction of
the repolarization wave is slower
than the wave of
depolarization). Sometimes a
small positive U wave may be
seen following the T wave (not
shown in figure at top of page).
This wave represents the last
remnants of ventricular
repolarization. Inverted or
prominent U waves indicates
underlying pathology or
conditions affecting
repolarization.
Q-T interval
The Q-T interval represents the
time for both ventricular
depolarization and repolarization
to occur, and therefore roughly
estimates the duration of an
average ventricular action
potential. This interval can range
from 0.2 to 0.4 seconds
depending upon heart rate. At
high heart rates, ventricular
action potentials shorten in
duration, which decreases the Q-
T interval. Because prolonged Q-
T intervals can be diagnostic for
susceptibility to certain types of
tachyarrhythmias, it is important
to determine if a given Q-T
interval is excessively long. In
practice, the Q-T interval is
expressed as a "corrected Q-T
( QTc)" by taking the Q-T interval
and dividing it by the square root
of the R-R interval (interval
between ventricular
depolarizations). This allows an
assessment of the Q-T interval
that is independent of heart
rate. Normal corrected Q-Tc
intervals are less than 0.44
seconds.
There is no distinctly visible wave
representing atrial repolarization
in the ECG because it occurs
during ventricular
depolarization. Because the
wave of atrial repolarization is
relatively small in amplitude (i.e.,
has low voltage), it is masked by
the much larger ventricular-
generated QRS complex.
ECG tracings recorded
simultaneous from different
electrodes placed on the body
produce different characteristic
waveforms.

Donnan equilibrium (which can
also be referred to as the Gibbs-
Donnan equilibrium) describes
the equilibrium that exists
between two solutions that are
separated by a membrane. The
membrane is constructed such
that it allows the passage of
certain charged components
(ions) of the solutions. The
membrane, however, does not
allow the passage of all the ions
present in the solutions and is
thus a selectively permeable
membrane.
Donnan equilibrium is named
after Frederick George Donnan ,
who proved its existence in
biological cells. J. Willard Gibbs
had predicted the effect some 30
years before.
The impermeability of the
membrane is typically related to
the size of the particular ion. An
ion can be too large to pass
through the pores of the
membrane to the other side. The
concentration of those ions that
can pass freely though the
membrane is the same on both
sides of the membrane. As well,
the total number of charged
molecules on either side of the
membrane is equal.
A consequence of the selective
permeability of the membrane
barrier is the development of an
electrical potential between the
two sides of the membrane. The
two solutions vary in osmotic
pressure, with one solution
having more of a certain type
(species) or types of ion that
does the other solution.
As a result, the passage of some
ions across the membrane will
be promoted. In bacteria , for
example, the passage of
potassium across the outer
membrane of Gram-negative
bacteria occurs as a result of an
established Donnan equilibrium
between the external
environment and the periplasm
of the bacterium. The potassium
enters in an attempt to balance
the large amount of negative ion
inside the cell. Since potassium is
freely permeable, it will tend to
diffuse out again. The inward
movement of sodium corrects
the imbalance. In the absence of
a Donnan equilibrium, the bulky
sodium molecule would not
normally tend to move across the
membrane and an electrical
potential would be created.

Various intrinsic, neural, and
hormonal factors act to influence
the rhythm control and impulse
conduction within the heart. The
rhythmic control of the cardiac
cycle and its accompanying
heartbeat relies on the regulation
of impulses generated and
conducted within the heart.
Regulation of the cardiac cycle is
also achieved via the autonomic
nervous system. The sympathetic
and parasympathetic divisions of
the autonomic system regulate
heart rhythm by affecting the
same intrinsic impulse
conducting mechanisms that lie
within the heart in opposing
ways.
Cardiac muscle is self-contractile
because it is capable of
generating a spontaneous
electrochemical signal as it
contracts. This signal induces
surrounding cardiac muscle
tissue to contract and a wave-
like contraction of the heart can
result from the initial contraction
of a few localized cardiac cells.
The cardiac cycle describes the
normal rhythmic series of cardiac
muscular contractions. The
cardiac cycle can be subdivided
into the systolic and diastolic
phases. Systole occurs when the
ventricles of the heart contract
and diastole occurs between
ventricular contractions when
the right and left ventricles relax
and fill. The sinoatrial node (S-A
node) and atrioventricular node
(AV node) of the heart act as
pacemakers of the cardiac cycle.
The contractile systolic phase
begins with a localized
contraction of specialized cardiac
muscle fibers within the sino-
atrial node. The S-A node is
composed of nodal tissue that
contains a mixture of muscle and
neural cell properties. The
contraction of these fibers
generates an electrical signal that
then propagates throughout the
surrounding cardiac muscle
tissue. In a contractile wave
originating at the S-A node, the
right atrium muscle contracts
(forcing blood into the right
ventricle) and then the left atrium
contracts (forcing blood into the
left ventricle).
Intrinsic regulation is achieved
by delaying the contractile signal
at the atrioventricular node. This
delay also allows the complete
contraction of the atria so that
the ventricles receive the
minimum amount of blood to
make their own contractions
efficient. A specialized type of
neuro-muscular cells, named
Purkinje cells, form a system of
fibers that covers the heart and
which conveys the contractile
signal from S-A node (which is
also a part of the Purkinje system
or subendocardial plexus).
Because the Purkinje fibers are
slower in passing electrical
signals (action potentials) than
are neural fibers, the delay allows
the atria to finish their
contractions prior to ventricular
contractions. The signal delay by
the AV node lasts about a tenth
(0.1) of a second.
The contractile signal then
continues to spread across the
ventricles via the Purkinje system.
The signal travels away from the
AV node via the bundle of His
before it divides into left and
right bundle branches that travel
down their respective ventricles.
Extrinsic control of the heart rate
and rhythm is achieved via
autonomic nervous system (ANS)
impulses (regulated by the
medulla oblongata) and specific
hormones that alter the
contractile and or conductive
properties of heart muscle. ANS
sympathetic stimulation via the
cervical sympathetic chain
ganglia acts to increase heart
rate and increase the force of
atrial and ventricular
contractions. In contrast,
parasympathetic stimulation via
the vagal nerve slows the heart
rate and decreases the vigor of
atrial and ventricular
contractions. Sympathetic
stimulation also increases the
conduction velocity of cardiac
muscle fibers. Parasympathetic
stimulation decreases
conduction velocity.
The regulation in impulse
conduction results from the fact
that parasympathetic fibers
utilize acetylcholine, a
neurotransmitter hormone that
alters the transmission of an
action potential by altering
membrane permeability to
specific ions (e.g., potassium ions
[K+]). In contrast, sympathetic
postganglionic neurons secrete
the neurotransmitter
norepinephrine that alters
membrane permeability to
sodium (Na+) and calcium ions
(Ca2+).
The ion permeability changes
result in parasympathetic
induced hypopolarization and
sympathetic induced
hyperpolarization.
Additional hormonal control is
achieved principally by the
adrenal glands (specifically the
adrenal medulla) that release
both epinephrine and
norepinephrine into the blood
when stimulated by the
sympathetic nervous system. As
part of the fight or flight reflex,
these hormones increase heart
rate and the volume of blood
ejected during the cardiac cycle.
The electrical events associated
with the cardiac cycle are
measured with an
electrocardiogram (EKG).
Disruptions in the impulse
conduction system of the heart
result in arrhythmias.
Variations in the electrical system
can lead to serious, even
dangerous, consequences. When
that occurs an artificial electrical
stimulator, called a pacemaker,
must be implanted to take over
regulation of the heartbeat. The
small pacemaker can be
implanted under the skin near
the shoulder and long wires
from it are fed into the heart and
implanted in the heart muscle.
The pacemaker can be regulated
for the number of heartbeats it
will stimulate per minute. Newer
pacemakers can detect the need
for increased heart rate when
the individual is under exertion
or stress and will respond.

Enzyme catalysis is a topic of
fundamental importance in
organic, bio-organic and
medicinal chemistry. This new
edition of a very popular
textbook provides a concise
introduction to the underlying
principles and mechanisms of
enzyme and coenzyme action
from a chemical perspective.
Whilst retaining the overall
structure of the first edition –
preliminary chapters describe the
basic principles of enzyme
structure and catalysis moving
through to detailed discussions
of the major classes of enzyme
processes in the later chapters –
the book has been thoroughly
updated to include information
on the most recent advances in
our understanding of enzyme
action. A major feature of the
second edition is the inclusion of
two-colour figures of the active
sites of enzymes discussed in the
text, in order to illustrate the
interplay between enzyme
structure and function. Problems,
with outline answers, at the end
of each chapter give the student
the chance to the check their
understanding of the material.
As a concise but comprehensive
account, Introduction to Enzyme
and Coenzyme Chemistry will
continue to prove invaluable to
both undergraduate and
postgraduate students of
organic, bio-organic and
medicinal chemistry.

Universities in Bangladesh
Bangladeshi universities are
mainly categorized into three
different types - Public,
government owned and
subsidized universities, Private,
private sector owned universities
and International, mainly
operated and funded by
international organizations such
as OIC. Currently xx public, yy
private and zz international
universities are operating their
activities in Bangladesh.
University of Dhaka is the oldest
university of the country
established in 1921. Bangladeshi
universities are affiliated with the
University Grants Commission
(UGC), a commission created
according to the Presidential
Order (P.O. No 10 of 1973) of the
Government of People's Republic
of Bangladesh.
Universities in Bangladesh play
very important role in the over all
development of the country. This
is evident form the fact that the
students and teachers of the
Dhaka University which was
established in the year 1921, was
at the forefront of the national
liberation struggle that led to the
independence of the country.
There are at present 54 private
Universities in Bangladesh.
The University Grant Commission
of Bangladesh would in fact be
responsible for supervising and
maintaining the quality of
education in all the public and
private Universities of
Bangladesh, as it is the statutory
apex body in the field of higher
education in Bangladesh.