STRUCTURE AND FUNCTION OF BLOOD VESSELS

INTRODUCTION
The main transport systems are the circulatory systems, in which substances are dissolved or suspended in liquid and carried from one part of the body to another in a system of tubes called vessels.

There are two main circulatory systems:
The blood circulatory system (sometimes called the cardiovascular system) and the lymphatic system.
The blood circulatory system is the main method of transporting oxygen, carbon dioxide, nutrients and metabolic breakdown products, cells of the immune and other defence systems, chemical messengers (hormones), other important substances (e.g. clotting factors).

The lymphatic system drains extra-cellular fluid from the tissues returning it to the blood circulatory system after passage through lymph nodes. This system is also involved in absorption of nutrients from the gut.

THE BLOOD CIRCULATORY SYSTEM
There are three types of blood circulatory system, two of which (systemic circulation and pulmonary circulation) depend on a pump, the heart, to push the blood around. The third type of circulation is known as a portal system. These are specialised channels that connect one capillary bed site to another but do not depend directly on a central pump. The largest of these in the human is the hepatic portal system which connects the intestines to the liver.

The systemic circulation transfers oxygenated blood from a central pump (the heart) to all of the body tissues (systemic arterial system) and returns deoxygenated blood with a high carbon dioxide content from the tissues to the central pump (systemic venous system).

As briefly mentioned above the systemic circulation supplies all the body tissues, and is where exchange of nutrients and products of metabolism occurs. All the blood for the systemic circulation leaves the left side of the heart via the aorta.

This large artery then divides into smaller arteries and blood is delivered to all tissues and organs. These arteries divide into smaller and smaller vessels each with its own characteristic structure and function. The smallest branches are called arterioles.
The arterioles themselves branch into a number of very small thin vessels, the capillaries, and it is here that the exchange of gases, nutrients and waste products occurs.

Exchange occurs by diffusion of substances down concentration and pressure gradients.
The capillaries then unite to form larger vessels, venules, which in turn unite to form fewer and larger vessels, known as veins.

The veins from different organs and tissues unite to form two large veins. The inferior vena cava (from the lower portion of the body) and the superior vena cava (from the head and arms), which return blood to the right side of the heart. Thus there are a number of parallel circuits within the systemic circulation.
The pulmonary circulation is where oxygen and carbon dioxide exchange between the blood and alveolar air occurs. The blood leaves the right side of the heart through a single artery, the pulmonary artery, which divides into two - one branch supplying each lung. Within the lung, the arteries divide, ultimately forming arterioles and capillaries; venules and veins return blood to the left side of the heart.

How Can I Stop Gum Disease?

How Can I Stop Gum Disease?
If you are asking yourself, "How can I stop gum disease?", a good way to start is to understand the conditions of the disease. The two basic types of gum diseases or periodontal diseases are gingivitis and periodontitis.

Gingivitis is the first phase of periodontal disease. It results when plaque forms on the teeth's surface and the gum line. When plaque builds up, the bacteria that compose it cause inflammation in the gums. A person with gingivitis has red and puffy gums that bleed easily.
Gingivitis develops into periodontitis over time. At this phase, bacterial infection damages the bones that support teeth and the connecting gum tissue resulting in pockets where more bacteria can flourish. This condition ultimately leads to tooth loss.

How can I stop gum disease?
Detecting and treating the problem while it has just started is the best way to put a stop to periodontal disease. Pay attention to your gum's health. Healthy gums should be pink in color, firm, odorless and should not bleed with normal brushing. If the condition of your gums is the opposite, you likely have a problem. Make sure to see your dentist regularly. Most people are not aware they have a problem until their dentist points out the problem to them.

How can I stop gum disease through clinical treatment?
Your dentist or periodontist may perform several cleaning procedures in your mouth. Root planing or scaling are ways to remove the buildup of plaque and tartar in your teeth and gums. Your dentist may also place antimicrobial liquid solutions beneath your gum line through a procedure called periodontal irrigation to wash out any remaining bacteria in the infected gums.
Severe gum diseases may require periodontal surgery, which removes the infected gum to expose and strip off bacteria. In case of critical bone loss, the dentist will perform a bone graft. To complete the surgery, the dentist will cover the treated area with a new gum line through a skin graft.

How can I stop gum disease naturally?
A diet filled with nutrients, especially Vitamin C, will boost your body's ability to combat bacterial infection. There are also natural home remedies to prevent and cure gum disease such as rinsing with chamomile to lessen inflammation and peppermint tea to fight bad breath. Natural dental products such as toothpastes made with tea tree oil helps prevent gum disease in a gentle yet effective way. Knowing these products and their applications keeps me from wondering "How can I stop gum disease?"

Supplements For Toning Your Blood Vessels

Several supplements have been found beneficial in maintaining or restoring normal blood-vessel tone.

Vitamin E. Numerous studies have confirmed the benefits of vitamin E in improving endothelial function. This ability to maintain normal blood vessel tone may partly account for vitamin E's benefits in preventing cardiovascular diseases. In an extreme case, focusing on " acute" endothelial dysfunction in smokers, researchers found that 600 IU of vitamin E daily led to significant improvements in blood-vessel tone. A combination of 400 IU of vitamin E and 500 mg vitamin C daily enhanced endothelial function in children genetically predisposed to heart disease.

Vitamin C. By itself, vitamin C can also improve blood vessel tone. In a study of patients with heart disease, researchers found that 2,000 mg of vitamin C protected against endothelial dysfunction after a high-fat meal. Similarly, 1,000 mg of vitamin C blunted the endothelial dysfunction caused by elevated blood levels of homocysteine.

14 Steps to Help Those With Sickle Cell Disease!

Sickle cell disease primarily affects people of African, Mediterranean, Middle Eastern, and Asian Indian ancestry. There is also a growing segment in the Latino-American population particularly those of Caribbean, Central American, and South American ancestry. In the United States one out of every 400 births has this disease. The most common type of sickle cell disease is sickle cell anemia. In our companion article "Understanding Sickle Cell Disease" we cover a lot of material about the cause and symptoms of this disease. The following paragraph is a very brief overview.

All types of sickle cell disease are caused by a genetic change in the hemoglobin portion of the red blood cell. Hemoglobin is the oxygen-carrying protein inside the red blood cell. Normal red blood cells are oval and flexible. Red blood cells in sickle cell disease have a tendency to reshape themselves into rod-like structures that resemble the curved blade of a sickle; thus, the term sickle cell. Sickle cells have a shorter life span than normal red blood cells. This results in chronic anemia and reduced oxygen to the tissues of the body. In addition, sickle cells are less flexible than normal red blood cells. This presents a problem since they can become trapped in the small blood vessels preventing blood flow to the body's tissues. This compromise in the delivery of oxygen to the tissues results in pain and potential damage to the associated tissues and organs.

Recent Research Highlights the Importance of Nitric Oxide!
Researchers at Duke University and Howard Hughes Medical Institute recently discovered one of the keys to the cause of pain in sickle cell disease. Their findings were reported in the January 31, 2005 Proceedings of the National Academy of Sciences . Their research showed that when normal red blood cells move through the arteries they release a signaling molecule that tells the arterial walls to expand. The signaling molecule is nitric oxide. Nitric oxide causes the smooth muscle in the blood vessel wall to relax which opens up the vessel to allow the cells to pass through.

For those with sickle cell anemia, when the red blood cells are distorted into the sickle cell shape, the researchers at Duke University discovered that the walls of the arteries don't expand. This distorted shape of the sickle cells, combined with the fact that they tend to clump together, ends up blocking blood flow through these small arteries and capillaries. The Duke researchers noted that as the blood pulses, the walls of the arteries didn't expand like they do with normal red blood cells.

Their research also noted that the degree of nitric oxide deficiency directly correlated with symptom severity. This means that the less nitric oxide produced the greater the pain. This Duke/HHMI study found that when nitric oxide was administered to people with sickle cell anemia their symptoms were relieved. One of the conclusions from this study was that abnormal nitric oxide processing may be the real cause of sickle cell circulatory restrictions. In addition to the Duke/HHMI study, several other studies found that the administration of nitric oxide to people with sickle cell anemia relieved symptoms.

How To Improve Your Bones Quality?

We are all aware that either we are old, young or just newborn, we all need a large amount of this mineral called calcium.
Research has shown calcium is very important to our body. Calcium is essential for healthy bones and teeth.
We all have heard from our parents, doctors and even TV commercials that calcium is important to us. What they haven't told us is that when we do not get enough calcium for our bones, but literally our body are robbing most of calcium from the food we eat. That is scary.

What is this mineral got to do with our body?
This is a type of mineral that helps in our muscle and nerves developments and to function properly. It's mandatory that we have it. We don't get to choose. When we do not have enough, and most of us do not, it will be taken from our bones. That part is actually the normal process.

How can we get into trouble?
It's what happens next that gets us in trouble. The calcium we take in is supposed to go replace that calcium that was just taken out of our bones. So if we don't take enough in, we literally lose bone. That's why we should take the calcium vitamin supplement if we're not able to eat enough calcium rich foods every day.

Are we losing calcium?
We also lose this mineral every day in skin cells that fall off by sweating and it's in our urine. This happens day in, day out. So what we have got to do is put it back every day.

Those who take supplements probably take the vitamin supplement calcium more than anything else because we all lose it and it's not as easy to get it back as it is say, vitamin C. No one should be deficient in vitamin C.

What are the foods that have calcium?
There are a lot of foods that contain calcium. We know that milk does. Low-fat milk and whole milk have calcium. Cheese and dairy products have calcium. So do green, leafy vegetables. The problem is as adults we need between 1000-1300 mg a day.

Advantages And Disadvantages Of Teeth Whitening

People generally have their teeth brightened to improve their smile and appearance. Whiter teeth reflect beauty and a good lifestyle. A brighter smile makes you less self-conscious and more confident.
A brighter smile draws in more attention and company. Your smile is elemental in shaping your personality and affirming your presence in a social gathering. A brighter smile minimizes the appearance of wrinkles on face, reflecting your energetic and youthful appearance.

A teeth whitening process is a key to a charming smile. People often adopt this process to enhance their smile and redefine their persona. The common techniques of teeth whitening are widely used and do not have major side effects if used under proper dental guidance and supervision.

However there are some disadvantages of teeth whitening. Though bleaching is very effective, a few short term problems, like sore teeth or gums may arise from application of excessive bleach. These also disappear when bleach is discontinued. If you are chemically sensitive then inform your dentist so that you can be weathered for sensitivity before applying a specific product.

Study shows that bleaching is completely effective and safe in more than 70% of individuals. While bleaching is generally the first choice because it is cheaper, crowns or veneers are better choices than bleaching in certain specific cases of teeth discoloration.
You might feel uncomfortable to wear the mouth tray. If you notice any such problem with the fit of your bleaching tray, call your dentist. They can make some adjustments that will minimize your problem.
Whitening does not work in the same way in all situations. The smokers might experience similar situations unless they abstain from continued smoking, specifically during the bleaching process.

Yellowish teeth respond comparatively better than brownish, grayish or purple stained teeth to the whitening procedure. Bluish-gray staining caused by medication (tetracycline) is more difficult to brighten and might require up to six months of home whitening or several in-office appointments to achieve satisfactorily whitening results. Teeth that have dark stains respond better to crowns, veneers, or bonding.

Only a rational guide towards different teeth whitening procedure would give you the proper confidence to make an informed and educated choice for the technique that is best suited fore your dental health. Your dentist plays an essential role in empowering you to find out the right technique through thorough dental examination and counseling.

If you are co-operative to your dentist and the technique on teeth whitening is determined by a participatory effort from you and your cosmetic dentist then the probability of successful completion of the process is obviously more. If post treatment instructions are followed properly then your efforts will be supported by long-lasting results and you will have a smile that will never fade away.

A Look At Some Of The Top Vitamins

Vitamins (combination of two words: Vital Amines) are the complex organic substance essential in small quantities to the metabolism (nutrition) in most animals. These are found in minute quantities in food, in some cases are produced by the body, and are also produced synthetically. The human body needs them to work properly, so that we can grow and develop just like we should. Their deficiency results in many serious disorders.

Vitamins are divided into two major groups: the 'fat-soluble vitamins' designated as vitamin A, vitamin D, vitamin E, and vitamin K, and the 'water-soluble vitamins' which include vitamin C and the group of molecules referred to as the vitamin B complex. Each of them has its own special role in the development of human body.
Vitamin A
Vitamin A, a fat-soluble vitamin, plays a really big part in eyesight and helps us to see in dim light and also at night. Vitamin A is also involved in the formation and maintenance of healthy skin, hair, and mucous membranes. In addition, it is necessary for proper bone growth, tooth development, reproduction and for the development of epithelial cells (that line any opening to the body e.g.; nose, throat, lungs, mouth, stomach, intestines and urinary tract).
Vitamin A can be found in eggs, milk, carrots, spinach, sweet potatoes, fish oil, liver (pork, lamb, chicken, turkey or beef), butter, broccoli, apricots, nectarines, cantaloupe, and orange or yellow vegetables or fruits.
The deficiency of vitamin A can cause two major disorders like: night blindness and drying of skin.

Vitamin B
Vitamin B itself is a complex of different vitamins like: B1, B2, B6, B12, niacin, folic acid, biotin and pantothenic acid. These B vitamins are very important in metabolic activity and in facilitating the red blood cell (which carry oxygen throughout your body). They also help your body make protein and energy.

The sources of vitamin B are leafy green vegetables seafood, beans, peas, citrus fruits, whole grains (such as wheat and oats), poultry, meats, eggs and dairy products (like milk and yogurt). Some bacteria in our large intestine also prepare some type of B-vitamins.
The deficiency of vitamin B can cause the disease "Beri Beri", cracked lips, weak muscles, malformation of red blood cells, affects normal growth and disturbs the nervous system.


Vitamin C
Vitamin C or ascorbic acid is a water-soluble, antioxidant vitamin that is vital to the production of collagen, a protein that gives structure to bones, cartilage, muscle, and blood vessels. It is important for keeping body tissues, such as gums and muscles in good shape and it helps in quick healing of wounds. In addition, it helps protecting the fat-soluble vitamins A and E as well as fatty acids from oxidation.
The vitamin C can be found in citrus fruits (like lemon & orange), cantaloupe, strawberries, tomatoes, broccoli, cabbage and in other fresh fruits and vegetables.
The deficiency of vitamin C affects the healthy skin; poor wound healing and can lead to a disease called "Scurvy" which causes bleeding in gums, easy bruising, bumps of coiled hair on the arms and legs, pain in the joints, muscle wasting, and many other problems.

Vitamin D
Vitamin D is a fat-soluble vitamin that regulates the formation of bone and the absorption of calcium and phosphorus from the intestine. It helps to control the movement of calcium between bone and blood, and vice versa. It is this vitamin you need for strong bones and teeth. In addition it helps your body absorb the amount of calcium it needs.

Vitamin D can be found in fish liver oil, egg yolks, milk and other dairy products fortified with vitamin D. It is also produced in our body in the presence of ultra violet light and sunlight.

The deficiency of vitamin D can cause weak bones and bowed legs (in children). And its excess can cause loss of appetite, weight loss, nausea, headache, depression and deposits of calcium in the kidneys.

Vitamin E
Vitamin E, a fat-soluble vitamin, is essential for the inhibition of oxidation in body tissues, formation of red blood cells, and also prevents breakdown of body tissues. It maintains the body tissues and protects the lungs from becoming damaged by polluted air.

This vitamin can be found in whole grains (such as wheat and oat), wheat germ, leafy green vegetables, sardines, egg yolks, nuts, bread, cereals and seeds.
The deficiency of this vitamin can cause many diseases like cancer, diabetes, heart disease, and Alzheimer's disease.

Fitness - Happy Haemoglobin

Interestingly, aerobic training also increases the haemoglobin in your blood which means you will have more red blood cells. After all, even if your lungs can process more oxygen, they need the requisite haemoglobin to absorb that oxygen. And this means that not only will you have more sponges to absorb and carry more oxygen to your tissues, but that your tissue can gladly unburden more carbon dioxide and rid your body off more wastes.

Becoming your own blood donor
With more haemoglobin to your blood-bank credit, it follows that you have more blood. Which means that your muscles get more of this wonderful life-giving fluid. But before we get into the 'muscular' regions, let us stop and view what happens at this stage.

If you are an inactive person, your blood vessels tend to become less efficient and your arteries harden due to lack of exercise. Thus, even the normal blood intake of flow becomes difficult for them. They put up a resistance which is how you get blood-pressure. For an average healthy, young person, the ideal blood pressure is 120/80. What do these figures mean? The first figure of 120 is the systolic pressure - when the heart is pumping blood into your system. The second figure of 80 is the diastolic pressure - it is when the heart has relaxed its pumping activity. In short, these two numbers show the maximum and minimum pressure in your blood vessels.

When you exercise, these blood vessels become more active and open up, their tone improves and they become more elastic. Being Nature's wonderful phenomenon, they even multiply in numbers. All these changes within your body give the blood a freeway and it flows on without any resistance from the arteries. This is how your blood pressure comes back to a normal healthy level. This is the point where your stamina improves. When you first begin to exercise, you may feel a little tired because it takes time for your lungs and blood vessels to take in extra oxygen. But as your lungs begin to take in more oxygen, simultaneously; your blood vessels open up, increasing the blood supply and thus carrying more oxygen to your tissue. One day, you realise you are not tired any more! If anything, you feel invigorated, your exercise seems easy as if you are going through all those movements without any effort. What has happened?

Simple. With your tissue being so rich in oxygen, the extra and now bigger blood vessels supply this life-saving gas to your heart tissue - making it more energetic and more efficient. More wastes are expelled in the process and your system is gradually purified. Which is why you feel like a million dollars and want to shout about your fitness from the rooftops!

A to Z of Vitamin C

Vitamin supplements are very important in prevention of unwanted health ailments that is partially caused by vitamin deficiencies. Many people today use vitamin supplements to make up for lost nutrients or the shortage of vitamins in their system. A shortage in Vitamin C may lead to scurvy, a condition that may causes tooth loss, hemorrhage, bruising, weakening of inability to fight infection, mild anemia, and bleeding. Essential amounts of vitamin C is necessary to promote overall health and well being. In many instances a good diet might be enough, but when it is not, vitamin supplementation necessary to take care of the deficiency.

Ascorbic Acid or Vitamin C is one of the most popular health supplements that is supposed to boost the immune system. It may strengthen the capillaries or the tiny blood vessels that carry oxygen and other necessary nutrients to all parts of the body via the bloodstream. Vitamin C is also a potent antioxidant, which means that it can eliminate free radicals from the body. It also helps deal with harmful oxygen molecules that could damage the cells. It is also believed that Vitamin C helps maintain cellular health and prevent cancer and a host of other health problems.

In addition to these health benefits, Vitamin C also plays an important role in promoting the health and beauty of the skin. This vitamin inhibits the production of melanin, the pigment that gives the skin its dark color. Vitamin C is also necessary for collagen synthesis, a process that improves skin elasticity and holds back the aging process. Applying skin-care products which contain Vitamin C may improve collagen production and result to a more youthful and hydrated looking skin.

The current recommended daily allowance (RDA) for Vitamin C is 75 milligrams (mg) a day for women and 90 mg a day for men to get the minimum amount the human body needs. However , medical specialists suggest that an intake of 200 mg is accepted since that amount is the most the human body can absorb at one time. Vitamin C can be found in citrus fruits like oranges, grapefruit, and tomatoes. Vegetables like bell pepper and broccoli are also good sources of Vitamin C.

It's easy to get ample amounts of Vitamin C from one's diet as long as it contains adequate amounts of fruits and vegetables. But if one feels there is a deficiency that needs to be taken care off, individuals are advised to take Vitamin C supplementation to take care of that deficiency. If a cold is starting to develop, it may also help to increase one's consumption. Medical studies show that taking 1000 mg of Vitamin C a day may reduce the severity of cold symptoms by about 20 percent.

Individuals who want to Vitamin C supplementation should seek the recommendation of doctors and other health professionals to side effects and drug interaction. Most people may take up to 2000 mg of Vitamin C without ill effects while some can develop diarrhea from as little as 500 milligrams. It is also important to drink plenty of water because Vitamin C needs to be dissolved in order to be metabolized properly. Sufficient water may also ensure that excess Vitamin C is eliminated from the body.

What are Capillaries?

Capillaries are tiny blood vessels, (about 10 micrometers in diameter) that form part of the circulatory system. These tiny structures are located within the tissues of the body and transfer blood from the arteries, through the tissues and back to the veins.

Capillary blood vessel's walls are thin and narrow and the red blood cells can only travel through them in single file. Substances such as oxygen, carbon dioxide, nutrients and wastes are passed through the walls of the capillaries. This makes the capillaries the main area of exchange between the fluid (called lymph) bathing the body tissues and the blood.
Because they are so numerous and their diameter is so small, Capillary blood vessel's purpose is to provide a large surface area in order to maximize diffusion of oxygen and nutrients.

What are the Functions of Capillaries?
The primary function of capillaries is to allow the exchange of materials between the blood and tissue cells. Because the capillaries are so small, these substances pass right through them in a process called diffusion.

Capillaries also supply blood to the organs. Strong capillaries perform the vital function of feeding the organ with amino acids, proteins and oxygen – if the organ cells do not receive oxygen, they will die. They also allow for waste products to be received from the organs. They then perform the very important function of transporting waste out of the body.

Tissues such as skeletal muscle, liver, and kidney have extensive capillary networks because they are extremely metabolically active and need an abundant supply of oxygen and nutrients. Other tissues, such as connective tissue, have a less abundant supply of capillaries.
Help for Capillaries

Strong capillaries are vital to the circulatory system, as they are the ultimate delivery network for nutrients and waste between the organs and the bloodstream. However, a poor diet, smoking, alcohol and all kinds of other environmental factors and pollutants can work to decrease the effectiveness of our circulatory systems, including the ever-important capillaries.

By maintaining a healthy diet without excessive fats, getting regular exercise and natural supplements, we can greatly strengthen capillary walls. This in turn leads to more efficient functioning of our many vital organs, and thus overall systemic health.