What causes Leukemia?

Leukemia is a cancer of the blood or bone marrow and is characterized by an abnormal proliferation (production by multiplication) of blood cells, usually white blood cells (leukocytes). Leukemia is a broad term covering a spectrum of diseases. In turn, it is part of the even broader group of diseases called hematological neoplasms. Currently, no one knows the cause of Leukemia, but there are certain factors and risk we should be looking out for.

• Radiation- The term "radiation" refers to various forms of energy, such as X rays and ultraviolet (UV) light found in sunlight. Radiation can tear chemicals apart, thus damaging or destroying cells. Some researchers believe that exposure to radiation can cause some forms of leukemia.


• Chemicals- Some types of chemicals are known to be carcinogens (pronounced car-SIN-o-genz). A carcinogen is anything that can cause cancer. Chemicals can cause cancer by damaging cells and the substances within them.


• Viruses- Some researchers believe that some types of leukemia are viral infections. A virus is a very small organism that can cause a disease. The link between viruses and leukemia is strong in some cases, but it has not been proved.


• Genetics- Leukemia tends to occur in some families more commonly than in others. This suggests that at least some forms of leukemia may be hereditary.

References:

http://http//www.faqs.org/health/Sick-V3/Leukemia.html

http://http//www.medicalnewstoday.com/articles/142595.php
Glossary:

Hematological Neoplasms- the types of cancer that affect blood, bone marrow, and lymph nodes.

What happens when there is a blood blockage in the coronary arteries?

The arteries that bring blood to the heart muscle (coronary arteries) can become clogged by plaque (a buildup of fat, cholesterol and other substances). This can slow or stop blood flow through the heart's blood vessels, leading to chest pain or a heart attack. Increasing blood flow to the heart muscle can relieve chest pain and reduce the risk of heart attack.
If you are suffering chest pain or other symptoms that may indicate a cardiovascular problem, undergo an angiogram (cardiac catheterization) to see if your coronary arteries are blocked by plaque. A blockage can cause a decrease in the supply of blood and oxygen to the heart and over time can lead to debilitating chest pain or a heart attack. Plaque material consists of fat, cholesterol, calcium and a variety of other cellular components like smooth muscle cells and blood cells. The deposition of this material occurs almost throughout life, starting even during childhood in many people. As this deposition progresses, the lumen gradually narrows and the blood flow is limited. The plaque material can also be somewhat brittle and fragile. Sometimes, the plaque cracks or fractures causing an acute obstruction with a sudden build-up of platelets which completely closes the lumen and flow ceases altogether. Most commonly, a heart attack then ensues.

References:

http://http//www.slrctsurgery.com/cabs.html

http://http//www.daviddarling.info/encyclopedia/C/coronary_artery_bypass_grafting.html

Glossary:

Cardiovascular disease or cardiovascular diseases refers to the class of diseases that involve the heart or blood vessels (arteries and veins).
Cardiac catheterization (heart cath) is the insertion of a catheter into a chamber or vessel of the heart. This is done for both investigational and interventional purposes.

What are the contents of our blood?

Normally, 7-8% of human body weight is from blood. In adults, this amounts to 4-5 quarts of blood. This essential fluid carries out the critical functions of transporting oxygen and nutrients to our cells and getting rid of carbon dioxide, ammonia, and other waste products. In addition, it plays a vital role in our immune system and in maintaining a relatively constant body temperature. Blood is a highly specialized tissue composed of many different kinds of components. Four of the most important ones are red cells, white cells, platelets, and plasma.

Red cells- or erythrocytes , are relatively large microscopic cells without nuclei.

White cells- or leukocytes , exist in variable numbers and types but make up a very small part of blood's volume--normally only about 1% in healthy people.

Platelets- or thrombocytes , are cell fragments without nuclei that work with blood clotting chemicals at the site of wounds.

Plasma- the relatively clear liquid water (92+%), sugar, fat, protein and salt solution which carries the red cells, white cells, platelets, and some other chemicals.

References:

http://http//anthro.palomar.edu/blood/blood_components.htm

http://sciencespot.net/Media/FrnsScience/bloodbasicscard1.pdf

Glossary:

Ammonia- a compound of nitrogen and hydrogen with the formula NH3.

What are blood vessels?

The blood vessels are the part of the circulatory system that transport blood throughout the body. There are three not major types of blood vessels: the arteries, which carry the blood away from the heart, the capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the back towards the heart.The arteries and veins have the same basic structure. There are three layers, from inside to outside while the capillaries have only one thick cell. Capillaries consist of little more than a layer of endothelium and occasional connective tissue.

References:

http://http//en.wikipedia.org/wiki/Blood_vessels
http://http//www.diabetes.org/diabetesdictionary.jsp

Glossary:

Endothelium- the thin layer of cells that line the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall.

What causes heart failure?

All of us lose some blood-pumping ability in our hearts as we age, but heart failure results from the added stress of health conditions that either damage the heart or make it work too hard.
All of the lifestyle factors that increase your risk of heart attack and stroke – smoking, being overweight, eating foods high in fat and cholesterol and physical inactivity – can also contribute to heart failure. Below are some of the conditions that lead to heart failure;

• Coronary artery disease - This happens when fatty deposits and cholesterol build up in your heart's arteries. This will prevent the blood from flowing through the vessels and less blood will enter the heart. This will result in either a chest pain ( Angina ) or a heart attack. Coronary artery disease can also contribute to high blood pressure which overtime can lead to heart failure.


• Diabetes - Diabetes increases the risk for developing heart failure. diabetes tend to develop hypertension and atherosclerosis from elevated lipid levels in the blood — both of which have been linked to heart failure.


• Abnormal heart valves - Heart valve problems can result from disease, infection (endocarditis) or a defect present at birth. When the valves don't open or close completely during each heartbeat, the heart muscle has to pump harder to keep the blood moving. If the workload becomes too great, heart failure results.

References:

http://http//www.heartfailure.org/eng_site/hf_causes.asp
http://http//www.americanheart.org/presenter.jhtml?identifier=324

Glossary:
Endocarditis- an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves (native or prosthetic valves).

Angina- chest pain due to ischemia (a lack of blood and hence oxygen supply) of the heart muscle.

Atherosclerosis- is the condition in which an artery wall thickens as the result of a build-up of fatty materials such as cholesterol.