Tuesday, November 24, 2009




" When you think of quitting, just think of why you started."

I think about dropping out of college every time things get hard, but I want to be a psychologist, which takes several years of challenges.

" Every time I fail, I always tell myself, ‘If I try it again, I will succeed’. Then, I take action."

Stand With Me: Build me up, don't tear me down. Support me and my efforts, don't trash me and my efforts. Guide me, don't mislead me. Be my friend, not my enemy. Love me, don't just like me. Hold me, don't just touch me. Receive me, don't reject me. Walk with me, don't walk away from me. Stand with me, STAND WITH ME!!!"
Copyright © 2009 Antonio Talbert
Either you're in or you’re out...Stand, Stand, Stand!!!!

Monday, November 23, 2009

Wednesday, November 4, 2009

ENVIRONMENTAL HEALTH HAZARDS
What Your Environment Means to You and Your Health
You may be thinking “Eh, the environment ‘schmironment.’” You have bigger things to worry about, right? But the “environment,” which you may feel is all that is “outside” your house and your regular life, does, in fact, find its way back to you. Back to your kitchen. Back to your water. Into the air you breathe and the food you eat.
The Elements
There are many things that occur in nature that may be hazardous to health. The effects of lead are being examined everywhere, from schools to houses built during a time when lead was used in the paint. Then there is also mercury. This substance has been used in thermometers for quite a while, but with the threat of the thermometers bursting, the risk may out weight the benefits of having these thermometers. Mercury is also becoming increasingly present in fish, threatening those who eat it with many different health risks.

Pollution
There is also pollution that can make you and your family sick. There is air pollution that threatens the lungs of many individuals. This includes everything from smog and pollen and of course tobacco smoke. Water pollution affects the water you drink, the water you cook with and the water with which you brew your coffee. There is also noise pollution, which many people do not think about when they initially consider pollution. But this type of pollution is harmful, causing distractions in the classroom and insomnia in the bedroom.
Modern Marvels that May Make you Sick
Then there are those scientific phenomena that seem like great advances in technology that may seem to be good things that can have negative impacts on humans. Electricity is one such example. The radiation emitted from electromagnetic fields are purported by many to encourage cancer in individuals exposed to it. There are also hormones and antibiotics injected into plants and animals that are meant to make your food taste and travel better. These chemicals can have negative effects, however.

Conclusion
Environmental health hazards are everywhere, and even though you may think you are shutting out the environment when you close your front door, things that impact the environment do impact you.

Don’t be a Lead Head: Find out What You Need to Know
There are many dangerous things out in your environment. The environment is more than just the outside alone. It is also your home, your workplace, your car etc. Everything that comprises your surroundings makes up your environment, and like anything else, there are the good and the bad. Lead, while it has it strengths, can be a definite health hazard to you and your family.
What Makes Lead Dangerous?
Regardless of how lead enters your body the effects on the body are still the same. Lead poisoning can have many negative affects. Most of the time, these negative effects attack the nervous system. Exposure to lead may also cause a loss of strength in carpals, metacarpals and phalanges as well as the ankles. There may also be a blood pressure increase as a result of the lead poisoning. It can also cause a decreased number of blood cells, a condition known as anemia. High levels of lead poisoning obviously have serious health side effects.
Where is Lead Poisoning a Threat?
Lead is often found in the paint of older homes. Most paints are no longer lead-based paints, but if your home was built in the 1970s and prior, your family may be at risk. Paint chippings can find their way into the food.
Those that are especially at risk include those individuals who are on demolition teams or renovating teams of older homes. The sanding can stir lead particles up into the air where they are easily inhaled. Also, welding, the repair of radiators, and the manufacturing of lead based batteries also may put one at risk.
How do I Protect Myself from Lead Poisoning?
There are many ways to reduce the threat of lead poisoning in your home. If your home has walls that were painted with lead based paint, re-painting the surfaces will allow you to seal the lead-based paint. Also, the National Institute of Health offers that lead solder may have been used on pipes before 1986. If your home is older than this, you will want to let the water run for a moment or two before using it to drink or cook with.

Pesticides: What you can’t See May Harm You!
Everyday you eat the food that you have purchased from the store, use the water out of your well or the city water system to drink, make your coffee and cook your food and breath the air around you. You may not think that anything seems dangerous or out of place about your day-to-day routine, but there may be something on the surface that may be making you sick: pesticides. Pesticides cling to the surface of fruits and vegetables, find their way to water sources, and combine with dust, pollen and other pollutants in the air. How can pesticides harm you and how can you avoid contact with them?
The Negative Affects of Pesticides
Farmers know that you do not want worms in your apples, fungi on your corn or weevils in your potatoes, so they use pesticides. While the process of eliminating these bothersome creatures from your food is in many ways a good thing, the negative affects of pesticides may outweigh the benefits. Pesticides can cause everything from itchy eyes and skin burns to horrible stomach problems and, in some cases, even death.
How to Keep Pesticides from Affecting Your Family
There are several ways to keep pesticides from hurting your family. Wash fruits and vegetables thoroughly even if the label says that they have been washed previously. If you handle a home garden or other areas in which you use pesticides, there are specific tips to learn to keep yourself safe. The first is to keep yourself informed. Read the label! Know what is in the pesticides that you are using on your own vegetables and fruits.
When you read the label, you will want to know the active ingredients. There should also be an EPA registration number on the label that will ensure that the product you are using is EPA reviewed. Keep track of the EPA’s signal words such as DANGER, CAUTION, or POISON. Be sure that you understand the first aid procedures should an accident such as a spill or ingestion occur, and be sure to understand how you should properly store all of your chemicals.

Air Pollution: What is in the Air You Breath?
Air pollution is a subtle, but ever-present threat to your health. Air pollution is created when “gases, droplets and particles” combine to make the air poorer in quality, according to Family Doctor. Neither the city nor the country is safe from the effects of air pollution.
The largest part of air pollution in cities is caused by ground-level ozone, which occurs when fuel and engine gases combine with sunlight in the air. Experts urge people to understand that ground-level ozone is not the beneficial ozone, which is the Earth’s protective layer that keeps out harmful sun radiation.
How Can Air Pollution Affect Me?
The symptomatic effects of air pollution are evident in the population. The first level of irritation can occur in the eyes, lungs and throat. There may be a tightening of the chest and coughing accompanying the air pollution. Most physicians claim that generally healthy people need not worry about the symptoms of air pollution as they will probably fade as the conditions improve.
Still, there are those who can have a more negative reaction to air pollution. Children are one example. Children who live in areas of high pollution may experience much more symptoms of illness, including earaches and bronchitis. Also, individuals with lung or heart disease may react more strongly to pollution than those who are healthy.
Protecting Yourself and Your Family
There are many ways to stay protected from air pollution. The best way to keep yourself and your family safe from air pollution is to be informed. Know what types of air pollution affect where you live. Is it the exhaust from cars or excessive pollen? Monitor the PSI or pollutant standard index so that you will be knowledgeable of when levels are higher than others.
Still, you can keep the affects of air pollution to a minimum. The first way, unfortunately, is to stay inside as much as possible when the conditions are less then favorable. Also, try to focus on your outdoor activities during the morning or after the sun sets. Physicians recommend keeping the exercise inside when pollution levels are high.


Water Pollution: Water, Water Everywhere and Not a Drop to Drink!
You wash your dishes with it. You wash your clothes with it. You may cook with it, make your coffee with it, you may even pour yourself a glass and drink. It is water and you think it is safe. The water you use in your daily life is clear, odorless and tasteless, which stands to reason that it must be harmless, right? Not necessarily. The threat of water pollution increases when natural water sources such as creeks, lakes, and even oceans are investigated. The truth is that water pollution is out there, and there are things that you can do to protect your family and steps you can take to prevent further water pollution.
What is Water pollution?
Water pollution is defined as large amounts of materials contaminating a body of water in an adverse way. Water pollution sources are lumped into two main types: a point source or a non-point source. Pollution that stems from a point source happens when a pollutant is directly entered into a waterway. An example is when sewage pipes burst and spill into a river. Non-point sources come from runoffs, such as from farm fertilizers.
Water Pollution Types
There are several different types of water pollutants, including toxins, organic substances, thermal pollution and ecological pollution. Toxic substances are elements that are not naturally occurring in the environment, such as pesticides. Organic substances are things that are natural but should not be in the water, such as manure or sewage. Thermal pollution might happen when factories and plants use water as a cooling agent. The heat can decrease the oxygen level which may kill the life within the water. Then, there is ecological pollution that occurs when natural causes pollute the water such as when a volcano erupts.
Specific Water Pollutants
There are several different toxins that can cause pollution in water. These include arsenic, cadmium, chlorine, chromium, cyanide, lead, nitrates and nitrites, sulphates, selenium, mercury and bacteria. Some of these can cause diseases among those who drink it or swim in it, while others can be fatal.
Conclusion
There are many ways that you can prevent water pollution. Try using natural solutions such as lemon juice, vinegar and salt. Refrain from pouring toxins down sinks. There are several other ways to prevent water pollution. Keeping the waters clean means keeping you and your family healthy.


Noise Pollution: More Harmful Than you May Think
When you think about pollution, your mind probably automatically turns to those types of pollution that you find more “threatening” such as air pollution and water pollution. But there is another type of pollution out there that may be negatively affecting your health-- noise pollution. Among other things, noise pollution can be a distraction for school children and can also cause insomnia.
How Noise Pollution is Measured
Noise and sound are measured in decibels. A decibel number of 65, for example, would cause distraction and is considered “intrusive.” This is about the level of your average, everyday traffic. Eighty decibels is considered annoying and is approximately the loudness of an alarm clock. Neither one of these is dangerous to your hearing, but can impair your ability to sleep. A decibel level of around 88 would occur in city traffic or in industrial work. Individuals exposed to this noise level for a lengthy period of time may experience actual hearing damage.
Once the decibel level goes above 80, prolonged exposure such as eight hours or more may cause increased tension, fatigue, changes in breathing, blood circulation and of course, loss of hearing. Sound at the level of 135 decibels is beyond annoying and intrusive, it becomes simply painful and can damage your hearing. A pneumatic drill would cause a sound like this.
Noise Pollution and Insomnia
Often people equate certain sounds with the promise of a good night’s sleep, such as rain and thunder, crickets, waves etc. For this reason, noise makers and fountains are often popular sleep aids. But these pleasant sounds are not the same as the “noise” that may be causing you to lose sleep. Noise can keep you from falling to sleep but it can also awake you if you are already asleep. Sleep-deprived individuals can feel lethargic and drowsy the entire day.
Lack of Concentration
Noise pollution can also inhibit the ability for school children and members of America’s work force to concentrate. Outside noise is especially troublesome for students who struggle with English as a second language. These students may have a hard enough time understanding what the teacher is saying much less being complicated by the affects of noise.


Mercury: Could You be at Risk of Becoming a Mad Hatter?
The disturbing effects that plagued hatters in times past may also affect you and your family today. What is mad hatters’ disease anyway? Hat creators often suffered from symptoms caused by the mercury that they used when processing their hats. Even though you may not work with mercury, you still may be exposed, as may your family members. How can mercury negatively affect you and how might you prevent mercury poison?
The Effects of Methylmercury
Methylmercury can cause many health problems for individuals, specifically for pregnant women. This chemical can cause neurological impairments including effects to memory, attention, motor skills, and much more. Often, this chemical is transmitted to an infant in the womb or in breast milk from a mother’s ingestion of fish. The EPA recommends not eating king mackerel, shark, swordfish and tilefish.
Elemental Mercury
Elemental mercury is also described by the EPA as metallic mercury. This type of mercury causes problems mainly when it is inhaled into the lungs. Elemental mercury is the physical, metallic liquid form of the metal. Inhalation may occur when mercury, such as the type in mercury thermometers, is spilled. The inhalation of elemental mercury can cause twitching, weakness, mood swings, tremors, headaches and many other health issues as examined by the EPA.
Other Types of Mercury
There are still other types of mercury in the environment. There are those compounds that the EPA considers “other mercury compounds”, which include both organic and inorganic types. These can be taken into the GI tract though ingestion. Inorganic mercury can cause skin rashes, a rise and fall in moods, muscle weakness and memory loss, according to the EPA. They may also affect the GI tract and kidneys.
Protecting Yourself
There are many ways to protect yourself from mercury poisoning. Eliminate the risk of coming in contact with elemental mercury by using thermometers that are not mercury based. Know the types of fish that may put you at risk for mercury poisoning and eat them sparingly. Still, the EPA argues that there are fish that you can eat without risk of mercury poisoning including tuna and salmon. Knowledge is key to keeping you and your family safe.


Radiation: What You Need to Know
Chances are you have already heard some of the buzz behind radiation concerns of many appliances and electronic gadgets such as microwaves and cell phones. Many people have become so accustomed to the convenience of the microwave and their mobile phones that radiation waves simply do not scare them. Still, there is evidence that radiation caused by many modern devices is a real threat and may pose serious health risks. One specific type of radiation accompanies EMFs or electromagnetic fields. Below are examples of what appliances and gadgets that human’s use which are shown to have definite electromagnetic fields.
Computers and Home Wiring
Computers and home wiring are sources of electromagnetic energy fields. Computers emit EMFs from each side of the computer, so sitting in front of the computer should not be an individual’s greatest concern. Screens that are placed over monitors will not block electromagnetic fields. The best way to determine how much electromagnetic radiation that is being beamed from your computer is to monitor it with a Gauss meter. Home wiring can also emit high electromagnetic field readings. This is especially the case in wiring that is improperly done.
Clocks and Telephones
Believe it or not, there are electromagnetic fields being emitted from your telephone and electric clocks. Telephones have relatively strong EMFs, made stronger by the fact that humans hold telephones so close to their head, which emits radiation to your brain. Electric clocks also have high emissions of electromagnetic radiation. Bedside clocks actual have EMFs that are equivalent to the EMFs that studies have shown may cause cancer.
Microwave
Microwaves are one of the most commonly discussed devices in the EMF radiation debates. Chances are that when you were little your mother would not let you stand close to the microwave when you were popping popcorn, and with good reason. According to Russian studies, all microwaves emit radiation that is well over the safety limit. The studies claim that microwaves turn certain food proteins into carcinogens, or cancer causers.
What to Do?
So what are people to do? Stop using phones, microwaves, alarm clocks and computers? That is highly unlikely to happen. Simple things like not sleeping with a clock right next to your head, but placing it six feet away will help you keep safer.


Hormones In Your Food: Do You Need Beefier Beef?
Americans are all about bigness, grandeur, and decadence. We buy in bulk and have our fries “Supersized.” But now, farmers are bulking up our chicken and beefing up our beef before it ever makes its way to your plate. Hormones are being added to the feed that is given to beef cattle, chickens and other livestock to make them more muscular and more pleasing to the slaughter houses. But are these hormones safe, and where do you and your family fit into the equation? Below are examples of hormones and antibiotics that are placed in your beef and some of the concerns that are arriving with this advance in technology.
rBGH: Recombinant Bovine Growth Hormone
One example of the hormones that are being placed in your meats is rBGH which stands for recombinant bovine growth hormone. But, believe it or not, this is not used for beefing up the bovine muscles for thicker, juicier meat. This hormone is used in the milk industry. rBGH is suggested to increase a cow’s production of milk by twenty-five percent. This hormone has been approved by the FDA as of 1994. Five to thirty percent of U.S. cows are injected with recombinant bovine growth hormone.
Experts are finding that rBGH is harmful in many different respects. On the one hand, the hormone can often make the cows themselves sick, say some experts. In addition, milk affected by rBGH is chemically different from natural milk. Critics of the practice claim that the milk has high levels of IGF-1, a natural growth hormone that in these crazy doses can increase chances of colon, breast, and prostate cancers.
Antibiotics in Chicken Feed
In addition to growth hormones, many types of food given to livestock contain antibiotics. The main concern that many experts have with using antibiotics in cattle, pigs or chickens is the threat of creating antibiotic resistant bacteria. According to the Organic Consumers Association, bacteria that has become antibiotic resistant can infect humans and create “fatal illnesses” if antibiotics will no longer work against them.
With all of these problems caused by hormones and antibiotics placed in meat and milk producing animals, it is no wonder organic food buying has become so popular.

Genetically Engineered Plants: You are what you Eat
Much research is being done on the effects that hormone injections and genetic engineering has on the food that you eat. One of the most studied is the effects that genetic engineering has on plants. In addition to causing health concerns, there are also many environmental hazards that are caused by genetic engineering. Friends of the Earth offers that there is biological pollution, chemical dependence, the growth of super weeds, use of pesticide plants and general threats to non-target organisms and organic agriculture.
Chemical Dependence: An Effect of Genetic Engineering
What in the world is chemical dependence and why should it matter to you? Chemical dependence refers to the need for farmers to use extreme amounts of herbicides and pesticides to kill weeds or pests that affect their crops. When plants are genetically engineered, they are often created to be highly resistant to pesticides and herbicides. Thus farmers can douse their crops with pesticides and herbicides with much more chemicals than they would actually need, creating lethal runoff that can harm you and your family.
Super Weeds and Pesticide Plants
The current trend of herbicide and pesticide resistance can be spread to “related plants’ by the wind or by the pollination of bees. This can create what Friends of the Earth calls super weeds. Plants propagated in this uncontrolled manner can grow out of control, like the Kudzu vines that infest much of the Southern United States. The new plant spin-offs can be hard, to near impossible to control, and can lead to very harmful effects on the environment.
There are also pesticide plants that are genetically created to produce toxin in the tissues, all tissues that make up the plant. This means that the toxins migrate into the edible parts of grain, potatoes, corn, and others, which can be harmful to humans and the rest of the ecosystem. These can lead to negative impacts on non-target organisms. For example, genetically engineered corn, according to Cornell University studies, can kill Monarch butterflies.
Conclusion
Science strives to make things better, and often they succeed. Still, there are those times when science can produce positives and negatives for the human health and for nature. Genetic engineering is one such example.


Antibiotics: The Good and the Bad
Before antibiotics, what did doctors use to treat infections, such as strep throat? There is no question about the fact that there are wonderful aspects to antibiotics. These drugs are used to treat many bacterial infections, from pneumonia to impetigo. But there are negatives to these drugs, and as a consumer and a patient you need to know the difference.
The Good Side of Antibiotics
Antibiotics are in many ways great in that they can cure many illnesses. These days when “flesh-eating bacteria” are terrorizing schools, the ability for antibiotics to cure such infections does bring comfort to American society. Illnesses that can be cured by antibiotics include sinus infections, kidney infections, bladder infections, and many other types of infections. In addition to the variety of infections antibiotics can fight, there is also a wide variety of antibiotics. There are tetracyclines, streptomycins and many other varieties.
The Bad Side of Antibiotics
Still, there are negatives when it comes to antibiotics. The first group of negatives is the side effects that accompany many of these antibiotics. Antibiotics often act without regard for the type of bacteria they are designed to attack. In other words, they do not know the difference between the good and the bad. This can often lead to an intense lowering of the natural flora in a person’s body the result of which can lead to everything from diarrhea to yeast infections.
Then, there is also the risk of creating antibiotic resistant strains of bacteria. When antibiotics are given and not taken completely, this can lead to stronger strains of the bacteria. Also, when doctors prescribe antibiotics for viral infections, such as the common cold and the flu, they are also adding to this danger.
What can You Do?
Most physicians suggest that there are several ways you can use antibiotics so that they work effectively and are not harmful to you or your child. The first way is to take the full prescribed amount. Also, do not use antibiotics that are old, even a few weeks old. Refrain from using a family member’s antibiotics and do not hoard extra antibiotics for the next time you may become sick.


Tobacco Smoke Pollution: What You Need to Know
Tobacco smoke pollution is more serious than many smokers would like to admit and most non-smokers would want to know about. According to experts, there are over 4,000 chemicals in tobacco smoke and thirteen of these the FDA will not even allow in any American food source. These include acetate, which is found in nail polish remover and paint stripper.
There is also arsenic, which is a poison that can lead to death. In addition, cigarette smoke contains methanol, benzene, carbon monoxide, DDT, formaldehyde, nickel, naphthalene and many other chemicals that are put into the air with cigarette smoke. Everyone who comes in contact with cigarette smoke can be negatively effected, especially children and even your pets.
Children and Tobacco Smoke
Children are often those who suffer the most from second hand smoke and smoke pollution. According to most health officials, smoke pollution increases the chances of many respiratory problems in children. These include asthma attacks, bronchitis and pneumonia. The EPA claims that 300,000 cases of respiratory infections a year are in response to second hand smoke. Over two hundred children per year die from illnesses brought about by cigarette smoke.
Your Pets and Tobacco Smoke
If you do not have children, but you have cats or dogs, your cigarette smoking will affect those that you love. One study indicates that environmental tobacco smoke can cause malignant lymphoma. The study, which was published in the American Journal of Epidemiology, monitored 80 cats with malignant lymphoma and 114 controls with renal disease. The study found that the risk increased with duration of exposure to the smoke and the amount of smoke in the house.
Conclusion
Many people who smoke know the risks that they present their own bodies with each time they take a puff. They may not fully understand, however, the danger in which they are putting their loved ones, including their animal friends, when they smoke. Air is something that humans must share with other humans and the environment around them. Environmental cigarette smoke is beyond harmful for both smokers and those around them.

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Wednesday, October 14, 2009

HOMEOSTASIS AND COAGULATION

The principle function of blood is to keep the internal environment of the body tissues constant and in this way to maintain homeostasis. Homeostasis is a term used to describe normal body functions, which include blood pressure, heart rate, body temperature, respiration and blood composition. In order to perform the processes involved in homeostasis, blood must be fluid. A mechanism known as hemostasis keeps the body fluid within the confines of the circulatory system.

Table of Contents
Hemostasis
Abnormal Hemostasis
Mechanisms Involved in hemostasis
Clotting Factors
Plasmatic Coagulation
Inhibitors
Extrinsic Pathway
Intrinsic Pathway
Intrinsic and Extrinsic Pathway
Antithrombin III

Normal Hemostasis
Blood normally is a fluid tissue as it circulates through out the body via the blood vessels. When vessels are injured, blood escapes and bleeding continues for a period of time but then slowly subsides. Several biologic systems play a role in stopping the flow of blood from an injured vessel. In addition to the vessels themselves, platelets and clotting factors interact to form a haemostatic clot. The formation of a haemostatic clot is a temporary measure and as the wound heals the clot slowly dissolves

Abnormal Hemostasis
There are two forms of abnormal hemostasis, which are described as follows:
a. Prolonged Bleeding: Following an injury bleeding may not stop in the same length of time it normally should. This may be the result of an abnormality involving the blood vessels, the platelets, clotting factors or increased activity of the fibrinolytic system. Hemophilia A is an example of prolonged bleeding directly related to an abnormal form of factor VIII, where the coagulant portion of the factor VIII molecule is deficient.
b. Thrombosis:
A thrombus or a clot in a blood vessel is formed by the coagulation of the blood. The formation of this clot is abnormal because its presence in a blood vessel obstructs the flow of blood to the tissues in that area, resulting in cellular changes. A heart attack can be one of the consequence of abnormal clot formation.

Mechanism Involved In Hemostasis
In the case of healthy subjects there exists a equilibrium between the coagulation potential on the one side and fibrinolytic potential + coagulation inhibitors on the other. In the fibrinolytic potential outweighs the coagulation potential or the coagulation factors are diminished then there is a risk of hemorrhage. If the coagulation potential outweighs the fibrinolytic potential or the inhibitors are diminished, there is a risk of thrombosis.
A delicate balance of components on both sides of the scale is required to maintain hemostasis.
1. Blood vessels:
The vascular system is composed of arteries, veins and the microcirculatory system. The blood vessels provide a non-thrombogenic surface allowing the blood to circulate in a closed vascular system. The nonthrombogenic surface is attributed to properties of the vessel walls and activities of platelets.
2. Platelets:
Platelets or thrombocytes are produced in the bone marrow by large cells called megakarycocytes. The normal numbers of platelets circulating are 150,000 to 450,ooo per cubic millimeter blood. To aid in hemostasis, platelets must be present in adequate number and must be functioning normally.
Platelets have Three major Functions:
a. Support Vascular integrity
Platelets support vascular integrity in two ways,
i. They help the blood vessels to maintain vascular integrity by donating membrane materials to the endothelial cells lining the vessel walls.
ii. Platelets also fill gaps that may occur between endothelial cells because of minimal damage or vasodilatation. By filling the gap a non trombogenic surface is maintained.
If a gap were allowed to remain and became larger, sub endothelial structures which are foreign to platelets and clotting factors would initiate fibrin formation.
b. Adhesion/Aggregation:
Platelets are considered to be first kind of defense in a haemostatic response to an injury. Following injury to a vessel wall, platelets adhere to the injured surface and quickly form a platelet plug. This activity keeps the blood within a closed vascular system. In the formation of the plug, platelets change as they aggregate irreversibly.
Irreversible aggregation causes platelet constituent to be released. Many of the constituent have an immediate effect upon the haemostatic response. One platelet constituent, known as platelet factor 3, becomes available on the surface of the platelets. Platelet factor 3 is a phospholipid and participates with certain clotting factors to produce thrombin with the ultimate formation of fibrin.

Clotting Factors
The clotting factors designations with some of the commonly used synonyms are as follows:
Factor I Fibrinogen
Factor II Prothrombin
Factor III Tissue thromboplastin
Factor IV Calcium
Factor V Plasma AcGLOB, Proaccelerin Labile factor
Factor VI Not assigned
Factor VII Proconvertin, Stable factor
Factor VIII Anti-hemophilic Globulin Hemophilia-A
Factor IX Christmas factor, Plasma Thromboplastin component
Factor X Stuart prower factor
Factor XI Plasma thromboplastin Antecendant (PTA)
Factor XII Hageman factor
Factor XIII Fibrin stabilizing factor, Prekallikrein, Fletcher factor, HMWK, Fitzgerald.
The clotting factors with the exception of factor III and factor IV are plasma proteins. Factor III is found in all tissues and is released when cells are damaged. factor IV is needed fro several interactions between clotting factors to occur in the production of fibrin.
Each clotting factor is designated by a Roman numeral and its most common synonym. Roman numerals are used most often referring to the clotting factors.
Notice that factor VI is missing. A plasma protein was given a Roman numeral but later studies showed it did not fulfill all the criteria established by the international nomenclature committee to qualify as a factor.
Prekallikrein, also known as Fletcher factor, and kininogen are plasma proteins. Although they are members of the kinin system, they are required for the complete activation of factor XII.
T simplify and for easy remembrance of clotting factors, they are separated into three major groups and each group shares certain characteristics. These three groups are:
a. Fibrinogen Group:
Factor I, V and XIII are produced in the liver. A portion of factor VIII molecule is produced in the liver and another portion by the endothelial cells. These factors are present in fresh normal plasma and adsorbed plasma.
They are not present in serum because they are consumed during the clotting process.
Coumarin, which is an oral anti-coagulant, has no effect upon their production, therefore, these factors are present in plasma obtained from individuals taking oral anticoagulants.
Factors VI and VIII are labile and their activity is rapidly lost in stored plasma. this is an important consideration in coagulation testing and in therapy.
b. Prothrombin Group:
Members in this group includes Factor II, VII, IX and X.
These clotting factors are produced in the Liver and Vitamin K is required for their synthesis.
These clotting factors are present in stored plasma. With the exception of Factor II, they are not totally consumed during the clotting process, therefore they are present in serum.
Because of the antogonistic action on Vitamin K by Coumarin medication, the concentration of these factors is reduced in plasma obtained from individuals taking oral anticoagulants.
c. Contact Group:
Members in this group include Factors XII, XI Prekallikrein and kininogen.
Factor XII, XI prekallikrein and Kininogen are synthesized in the liver.
Factor XII and XI are fairly stable and may be found in stored plasma and adsorbed plasma. they are not consumed during the clotting process, therefore, they are also present in serum.

Plasmatic Coagulation
About 20 factors (proteins) are involved which circulate in blood as inactive precursors (A substance that precedes the formation of another substance).
Activation signifies conversion to an enzyme which in its turn activates the subsequent factor.
Distinction is to be made between two activation pathways Namely:
a. Intrinsic pathway: in which only intravascular plasmatic factors and those released by platelets are involved.
b. Extrinsic Pathway: in which what are known as tissue thromboplastine are released from the surrounding tissue by injury and initiate the coagulation process.
Both pathways lead to the conversion of prothrombin to thrombin, which converts ion of fibrin webs provides the basis for measurements of coagulation times.
Activation Process:
Coagulation factors are present in the blood as inactive precursors awaiting activation together with calcium and phospholipids by their activated antecedent factor. Activation means consumption, and hence a transitory fall in concentrating.

Inhibitors
The achievable coagulation system conceals potential risk for the individual. Hyper and hypo function disturb the equilibrium. It must be adaptable enough to maintain the theological (flow) properties of the blood the one hand, and on the other hand to prevent the passage of blood into the tissue by sealing the capillaries. Activation of the system has therefore to remain limited to the extent and location of the need. This task is performed by inhibitors which block the enzymatic activity. The most important inhibitor is antithrombin III. Others include alpha-macro-globulin and alpha-antitrypsin.
Fibrinolysis:
After the fibrin has fulfilled its function, it must be catabolised in a process known as fibrinolysis. Two possible activation pathways lead finally to conversion of the protein plasminogen into the enzyme plasmin, which in its turn cleaves fibrin into even smaller, and hence soluble, degradation products.
Extrinsic Pathway
In the case of injury, tissue thromboplastin passes into the blood and activates Factor VII to Factor VII a, which in turn activates Factor X. Here begins the section of the cascade common to both activation pathways. Namely, Factor X a- with Factor V as accelerator- activates the prothrombin (Factor II) to thrombin (Factor II a). Thrombin cleaves fibrinogen, thereby initiating the formation of fibrin.
The extrinsic pathway is monitored with the aid of the prothrombin time test. In the test, we create the same conditions as in vitro in order to launch this part of the cascade. The time required for the formation of first fibrin web is the prothrombin time which is measured in terms of seconds. This test measures the collective activity of clotting factors I, II, VII and X.
Use of Prothrombine Time Test:
1. The test is most often used to monitor oral anticoagulation therapy.
2. It is also used as a sensitive indicator for dysfunction of the liver.
Intrinsic Pathway
Contact with a foreign surface effects the activation of Factor XII. This triggers a regular cascade of activity namely via Factor XI, IX and VII to the common end pathway and hence the formation of fibrin. The intrinsic pathway is monitored with the aid of a Partial thromboplastin time.
Uses of activated partial thromboplastin time:
1. It is used as screening procedure to detect clotting factors.
2. It is used to monitor heparin therapy.
3. It is used to monitor replacement therapy in individuals with a clotting factor deficiency.
Extrinsic and Intrinsic Pathway
The inactive coagulation factors present in the plasma are to some extent assigned to two different activation pathways. From factor X onwards the cascade then proceeds jointly upto fibrin. This fibrin clot is initially of a loose structure. In the presence of activated factor XII it is stabilized to a mechanically firm clot which makes the haemostasis permanent. Since Factor XII does not act on the fibrin until the latter is formed, determination of this factor requires a separate test system.
Screening for Coagulation Disorders:
The activated partial thromboplastin time in conjunction with prothrombin time frequently permits a crude localization of a coagulation defect is probably to be found in Factor XII, is prolonged, the defect is probably it could well be matter of a factor VII deficiency. If, however, both screening tests are pathological, then the deficiency is more likely to have arisen in the joint end pathway of factors X, V, II and I.
Thrombin Time:
The end point of plasmatic coagulation is the activation of Prothrombin (factor II) to Thrombin(II a). Thrombin rapidly converts fibrinogen into fibrin. Antithrombins as the name implies are counteractive.
Thrombin normally converts fibrinogen into fibrin. This reaction is inhibited by fibrin, FDP and by antithrombins. If such products are present in the plasma to an increased extent, then the TT is prolonged.
The same occurs when the fibrinogen level is lowered, as in the case of augmented fibrinolysis or during a fibrinolytic therapy. One of the uses of this test is therefore in the monitoring of fibrinolytic (Strepto Kinase) or thrombolytic (Heparin) therapy.

Antithrombin III
Antithrombin III is a plasma protein. It is a naturally occurring inhibitor to the coagulation system. It is also the cofactor for heparin. Adequate levels of Antithrombin III must be present in plasma for heparin to exert its anticoagulant effect. Antithrombin III slowly inhibits the activity of activated clotting factors XII a, XI a, IX a and X a. It also neutralizes the active enzyme thrombin.
In order for heparin to exert the its anticoagulant effect, it must form a complex with antithrombin III. Once heparin is given, it complexes with antithrombin III and immediately the AT III heparin complex increases the speed of inhibitory activity.

Urgent and Massive Transfusion

Urgent Transfusion
Urgent transfusion refers to administration of Red Blood Cells (RBCs) before the completion of standard pretransfusion testing, when a delay in transfusion may imperil the patient. Implicit is the understanding that it is necessary to reestablish both oxygen-carrying capacity and intravascular volume. In hypovolemic shock, most authorities recommend immediate volume restoration with crystalloid or colloid solutions, however a warning has recently been issued regarding possible adverse effects of albumin so-
lutions in critically ill patients.1"3 If volume replacement leads to clinical stabilization, transfusion is less urgent and should await the completion of compatibility testing.
If transfusion is necessary before completion of compatibility testing, group O RBCs should be used. Whenever possible, D-negative RBCs should be used in females of childbearing potential and children to avoid the possibility of sensitization to the D antigen. The patient's physician must sign a statement indicating the nature of the emergency either before or after the uncross-matched blood is issued. If the patient's screen for unexpected red cell antibodies is negative, the transfusion of uncrossmatched but type-specific Whole Blood or of type-compatible RBCs carries a very low risk of being incompatible.3This safety margin is dependent, however, on correct identification of the patient, the pretransfusion blood sample, and the blood components to be infused. Guidelines for conditions under which it is safe to switch the patient to type-specific blood are available.7 In the near future, administration of artificial oxygen carriers may provide a therapeutic bridge to the use of fully compatible blood when emergency transfusion is required.
Massive Transfusion
Massive transfusion is defined as the replacement of one or more blood volumes within 24 hours. A blood volume is estimated as 75 mL/kg or about 5000 mL (10 or more units of Whole Blood) in a 70-kg adult Patients requiring massive transfusion frequently develop multiple complications related to hypovolemia, tissue ischemia, and acid-base disturbances. Many of these metabolic, coagulation, respiratory, and other complications have been ascribed solely to the transfusion of stored blood, but are caused principally by tissue damage or hypoperfusion secondary to trauma or hemor-rhage.l2>14 Hypothermia may impair hemostasis and should be avoided by warming the patient, the crystalloid solutions administered, and if indicated, the blood.
Massive transfusion may be an indication for the use of Whole Blood. However, Whole Blood may not be available, and RBCs administered with crystalloid or colloid solutions are
equally effective in restoring blood volume and oxygen-carrying capacity.15 The patient's history, vital signs, clinical situation, and hematocrit determine the urgency of red cell support. Plasma and platelet support should be based on the presence or absence of microvascular (not surgical) bleeding and on the results of screening tests of hemostasis [prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen, and platelet count].
Many patients with major hemorrhage who require massive transfusion develop a coagulopathy, but not all develop diffuse microvascular bleeding as a result. This coagulopathy may be characterized by thrombocytopenia, hypofibrinogenemia, and prolongation of the PT and the PTT. The etiology of this coagulopathy can be multifactorial, and may be caused by consumption of coagulation factors or hemodilution. Patients with severe tissue injury and prolonged hypotension are more likely to develop diffuse microvascular bleeding and require greater hemostatic support." Preestablished formulas to guide component replacement, such as giving 2 units of Fresh Frozen Plasma (FFP) or 6 units of Platelets with every 5 units of RBCs, are not efficacious." Strict reliance on these formulas may provide insufficient support to patients with consumptive coagu-lopathies and unnecessary transfusion of components to those who do not develop disseminated intravascular coagulation (DIG). Through careful monitoring of laboratory tests of hemostasis, the timely and judicious transfusion of Platelets, FFP, or Cryoprecipitated AHF can be reserved for patients with documented deficiencies.
Mild-to-moderate prolongation of the PT or the PTT does not accurately predict subhemostatic clotting factor levels. Marked prolongations of these tests Often reflect factor levels below 20-30% (see Overview of Hemostasis), however, and supplemental FFP or Cryoprecipitated AHF may then be indicated." In bleeding patients with thrombocytopenia, platelets should be administered to maintain a platelet count of 50,000/pL. Patients who continue to bleed despite adequate levels of platelets or coagulation factors should be thoroughly re-evaluated and considered for surgical exploration. Close communication between
clinicians and the transfusion service director is essential in these cases.

CARDIAC MUSCLE CELLS

In order to understand how the heart regulates itself, there are some characteristic features of cardiac muscle cells to consider more closely.
All resting muscle cells, including cardiac muscle cells, are polarized, i.e. the interior of the cells are negative with respect to the exterior. Each cell is surrounded by a membrane being permeable to particular ions, especially Na*, K*.
In the resting cell, there is an equilibrium between the concentration of these ions within the cell and outside of the cell, but the distribution of the ions is unequal, there being a high extracellular concentration of Na* and a high intracel-lular concentration of K*. Since there are more extracellular Na+ ions than intracellular K* ions, the interior of the cell will be negative with respect to the exterior, creating the membrane potential.
If a microelectrode is inserted into the cell, this resting membrane potential can be measured as negative, approx. -90 mV.
When the cell receives a stimulus, e.g. if an electrical current is applied to to its surface, the membrane potential changes and becomes less negative, triggering an influx of Na* ions into the cell.
If only a very weak current is applied, it will result merely in a transient, moderate reduction of the membrane potential. A stronger stimulus, however, will cause the number of Na+ ions pouring into the cell to become so great that the resting membrane potential breaks down: the cell is activated and contracts. The formerly negative membrane potential rises abruptly to zero and beyound to an overshoot of approximately +30 mV. For cardiac cells this depolarisation occurs at approx. -50 mV, called the threshhold potential.
After the rapid cell depolarization and contraction, Na* ions are pumped out of the cell again, causing at first a rapid phase of repolarisation towards zero potential, then a plateau phase with the potential maintained at or near zero, and finally a rapid repolarisation phase to restore the resting membrane potential.
Tiie entire process of potential changes from the beginning of depolarization to the end of repolarisation is called the action potential of the cell.
Depolarization in cardiac muscle cells is a rather short process that lasts only a few milliseconds, whereas repolarisation lasts for about 500-600 ms.
The cardiac muscle cell can only depolarize when the membrane potential is more negative than the threshold potential, i.e. it is not possible to depolarize the cell in the repolarization period, the cell is said to be in the refractory period. This indicates that impulses can only spread to non-excited cells.
In ordinary muscle, the cells lie parallel and the depolarization of one cell does not influence its neighbouring cells. Myocardial cells, however, are joined end-to-end by structures to form an interrelated network. Therefore, they are able not only to contract but also to initiate a depolarisation of their neigbour cells and propagate the contraction to each other. In this way all cells are stimulated, providing coordinated contraction of the heart and effective pumping.