Anemia

what makes a person susceptible to anemia

-low erythropoeitin levels -genetics: sickle cell anemia -necessary building blocks

Why does the RBC have a vast surface area? can the RBC reproduce or maintain itself? what is the average lifespan like of an RBC? where are RBCs lysed?

Although the mature RBC has no nucleus, it does have a vast surface area to improve its ability to transport oxygen and carbon dioxide. Because it lacks a nucleus, the RBC cannot reproduce or maintain itself, and so it will eventually wear out. The average lifespan of an RBC is about 120 days. At that time, the elderly RBC is lysed in the liver, spleen, or bone marrow.

What 3 anemias are there?

Anemia can be categorized as deficiency (iron deficiency anemia), megaloblastic (folic acid or vitamin B12 deficiency), or hemolytic (sickle cell).

Why is blood important what is it composed of

Blood is essential for cell survival because it carries oxygen and nutrients and removes waste products that could be toxic to the tissues. It also contains clotting factors that help to maintain the vascular system and keep it sealed. In addition, blood contains the important components of the immune and inflammatory systems that protect the body from infection. Blood is composed of liquid and formed elements. 1)The liquid part of blood is called plasma. Plasma is mostly water, but it also contains proteins that are essential for the immune response and for blood clotting. 2)The formed elements of the blood include leukocytes (white blood cells), which are an important part of the immune system; erythrocytes (red blood cells [RBCs]), which carry oxygen to the tissues and remove carbon dioxide for delivery to the lungs; and platelets, which play an important role in coagulation

Folic acid deficency what is folic acid essential for? what kind of cells does it effect? what food sources contain folic acid?

Folic acid is essential for cell division in all types of tissue. Deficiencies in folic acid are noticed first in rapidly growing cells, such as those in cancerous tissues, in the GI tract, and in the bone marrow. Folic acid is very important for the developing fetus, a site of very rapidly growing cells. Pregnant women are urged to take folic acid supplements to help prevent fetal abnormalities, particularly neural tube defects. Most people can get all the folic acid they need from their diet. For example, folic acid is found in green leafy vegetables, milk, eggs, and liver. Deficiency in folic acid may occur in certain malabsorption states, such as sprue and celiac diseases. Malnutrition that accompanies alcoholism is also a common cause of folic acid deficiency. Repeated pregnancies and extended treatment with certain antiepileptic medications can also contribute to folic acid deficiency. Folic acid deficiency is treated by the administration of folic acid or folate.

What are the building blocks of an RBC? what part of RBC can't be recycled?

The building blocks of the RBC (e.g., iron, vitamin B12) are then recycled and returned to the bone marrow for the production of new RBCs. The only part of the RBC that cannot be recycled is the toxic pigment bilirubin, which is conjugated in the liver, passed into the bile, and excreted from the body in the feces or the urine. Bilirubin is what gives color to both of these excretions. Erythropoiesis is a constant process by which about 1% of the body's RBCs are destroyed and replaced each day.

Vit. B12 deficency

Vitamin B12 is used in minute amounts by the body and is stored for use if dietary intake falls. It is necessary not only for the health of the RBCs, but also for the formation and maintenance of the myelin sheath in the central nervous system (CNS). It is found in the diet in meats, seafood, eggs, and cheese. Strict vegetarians who eat nothing but vegetables may develop a vitamin B12 deficiency. Such individuals with a dietary insufficiency of vitamin B12 typically respond to vitamin B12 replacement therapy to reverse their anemia. The most common cause of this deficiency, however, is inability of the GI tract to absorb the needed amounts of the vitamin. Gastric mucosal cells produce a substance called intrinsic factor, which is necessary for the absorption of vitamin B12 by the upper intestine. Pernicious anemia occurs when the gastric mucosa cannot produce intrinsic factor and vitamin B12 cannot be absorbed. The person with pernicious anemia will complain of fatigue and lethargy and will also have CNS effects because of damage to the myelin sheath. Patients will also complain of numbness, tingling, and eventually lack of coordination and motor activity. Pernicious anemia was once a fatal disease, but it is now treated with parenteral or nasal vitamin B12 to replace the amount that can no longer be absorbed.

Iron deficency anemia

cells in the body require some amount of iron, but iron can be very toxic to cells, especially neurons. To maintain the needed iron levels and avoid toxic levels, the body has developed a system for controlling the amount of iron that can enter the body through intestinal absorption. Only enough iron is absorbed to replace the amount of iron that is lost each day. Once iron is absorbed, it is carried by a plasma protein called transferrin, a beta-globulin. This protein carries iron to various tissues to be stored and transports iron from RBC lysis back to the bone marrow for recycling. Only about 1 mg of iron is actually lost each day in sweat, in sloughed skin, and from GI and urinary tract linings. Because of the body's efficient iron recycling, very little iron is usually needed in the diet, and most diets adequately replace the iron that is lost. However, in situations in which blood is being lost, a negative iron balance might occur, and the patient could develop iron deficiency anemia. This can occur in certain rare GI diseases in which the patient is unable to absorb iron from the GI tract, but

why do people with kidney failure have anemia

kidneys are no longer producing erythropoeitin

Megaloblastic anemia what vitamin and mineral are ususally missing/

result from insufficient amounts of folic acid or vitamin B12 to adequately create the stromal structure needed in a healthy RBC, causing a slowing of nuclear DNA synthesis. This effect occurs in rapidly dividing cells such as the bone marrow. The bone marrow contains a large number of megaloblasts, or large, immature RBCs, and because these RBCs are so large, they become crowded in the bone marrow and fewer RBCs are produced, increasing the amount of immature cells in circulation. Cells in the GI tract are additional examples of cells that are often affected. When the GI tract is involved, this can result in the appearance of a characteristic red and glossy tongue and diarrhea. Another type of anemia is megaloblastic anemia, which involves decreased production of RBCs and ineffectiveness of those RBCs that are produced (they do not usually survive for the 120 days that is normal for the life of an RBC). Patients with megaloblastic anemia usually have a lack of vitamin B12 or folic acid.

what does anemia result from?

results from some alteration in erythropoiesis, the process of RBC production, which occurs in the myeloid tissue of the bone marrow. The rate of RBC production is controlled by the glycoprotein erythropoietin, which is released from the kidneys in response to decreased blood flow or decreased oxygen tension in the kidneys. Under the influence of erythropoietin, an undifferentiated cell in the bone marrow becomes a hemocytoblast. This cell uses certain amino acids, lipids, carbohydrates, vitamin B12, folic acid, and iron to become an immature RBC. In the last phase of RBC production, the cell loses its nucleus and enters circulation. This cell, called a reticulocyte, finishes its maturing process in circulation

Hemolytic anemia

which involves a lysing of RBCs because of genetic factors or from exposure to toxins. Sickle cell anemia is a type of hemolytic anemia

what must bone marrow have inorder to produce healthy RBCs?

•Adequate amounts of iron, which is used in forming hemoglobin rings to carry the oxygen .•Minute amounts of vitamin B12 and folic acid, to form a strong supporting structure that can survive being battered through blood vessels for 120 days. •Essential amino acids and carbohydrates to complete the hemoglobin rings, cell membrane, and basic structure.

iron deficiency anemia is also a relatively common problem in certain groups, including the following:

•Menstruating women, who lose RBCs monthly •Pregnant and lactating women, who have increased demands for iron •Rapidly growing adolescents, especially those who do not have a nutritious diet•Persons with GI bleeding, including individuals with slow bleeding associated with use of nonsteroidal anti-inflammatory drugs The person with this type of anemia may complain of being tired because there is insufficient oxygen delivery to the tissues. These conditions are usually treated with iron replacement therapy (see section on iron preparations).