18.- CIRCULATORY SYSTEM
The circulatory
system is an organ system that passes
nutrients (such as amino acids, electrolytes and lymph), gases, hormones, blood cells, etc. to and from cells in the body to help fight diseases, stabilize body temperature and pH, and to maintain homeostasis.
Bone
marrow examination refers to the pathologic analysis of samples of bone marrow obtained by bone
marrow biopsy (often called a trephine biopsy) and bone
marrow aspiration. Bone marrow examination is used in the diagnosis of a
number of conditions, including leukemia, multiple myeloma, lymphoma, anemia, and pancytopenia. The bone marrow produces the cellular elements of
the blood, including platelets, red blood cells and white blood cells. While much information can be gleaned by testing the
blood itself (drawn from a vein by phlebotomy), it is sometimes necessary to examine the source of
the blood cells in the bone marrow to obtain more information on hematopoiesis; this is the role of bone marrow aspiration and
biopsy. 
BLOOD TRANSFUSION
Blood transfusion is the
process of receiving blood products
into one's circulation intravenously.
Transfusions are used in a variety of medical conditions to replace lost
components of the blood. Early transfusions used whole blood, but
modern medical practice commonly uses only components of the blood, such as red blood cells, white blood cells, plasma, clotting factors, and platelets.
Is a decrease in number of red blood cells (RBCs) or less
than the normal quantity of hemoglobin in the blood. However, it can include decreased
oxygen-binding ability of each hemoglobin molecule due to deformity or lack in
numerical development as in some other types of hemoglobin
deficiency.
Because hemoglobin (found inside RBCs) normally carries oxygen from the lungs to the tissues, anemia leads to hypoxia (lack of oxygen) in organs. Since all human cells depend on oxygen for survival, varying degrees of anemia can have a wide range of clinical consequences.
Most commonly, people with anemia
report nonspecific
symptoms of a feeling of
weakness, or fatigue, general malaise and sometimes poor concentration. They may also
report dyspnea (shortness of breath) on exertion. In very severe
anemia, the body may compensate for the lack of oxygen-carrying capability of
the blood by increasing cardiac output. The patient may have symptoms related to this, such
as palpitations, angina (if pre-existing heart disease is present),
intermittent claudication of the legs, and symptoms of heart failure.
This system may be seen strictly as a blood
distribution network, but some consider the circulatory system as composed of
the cardiovascular system, which
distributes blood, and the lymphatic system,] which returns excess filtered blood plasma from the interstitial
fluid (between cells) as lymph. While humans, as well as other vertebrates, have a closed cardiovascular system (meaning that
the blood never leaves the network of arteries, veins and capillaries), some invertebrate groups have an open cardiovascular system. The most
primitive animal phyla lack circulatory systems. The lymphatic system, on
the other hand, is an open system providing an accessory route for excess
interstitial fluid to get returned to the blood.
Two types of fluids move through the circulatory system: blood and lymph. Lymph is essentially recycled blood plasma after it has been filtered from the blood cells and returned to the lymphatic system. The blood, heart, and blood vessels form the cardiovascular (from Latin words meaning 'heart'-'vessel') system. The lymph, lymph nodes, and lymph vessels form the lymphatic system. The cardiovascular system and the lymphatic system collectively make up the circulatory system.
Two types of fluids move through the circulatory system: blood and lymph. Lymph is essentially recycled blood plasma after it has been filtered from the blood cells and returned to the lymphatic system. The blood, heart, and blood vessels form the cardiovascular (from Latin words meaning 'heart'-'vessel') system. The lymph, lymph nodes, and lymph vessels form the lymphatic system. The cardiovascular system and the lymphatic system collectively make up the circulatory system.
BLOOD
TEST
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick. Blood tests are used to determine physiological and biochemical states, such as disease, mineral content, drug effectiveness, and organ function. They
are also used in drug
tests
.
BONE MARROW EXAMINATION
BONE MARROW EXAMINATION
BLOOD TRANSFUSION
Blood transfusion is the
process of receiving blood products
into one's circulation intravenously.
Transfusions are used in a variety of medical conditions to replace lost
components of the blood. Early transfusions used whole blood, but
modern medical practice commonly uses only components of the blood, such as red blood cells, white blood cells, plasma, clotting factors, and platelets.
They are
typically only recommended when a person's hemoglobin levels fall below 8g/dL. One may consider transfusion
for people with symptoms of cardiovascular
disease such as chest pain
or shortness of breath. Globally around 85 million units of red blood cells are
transfused in a given year.
ANEMIA
Because hemoglobin (found inside RBCs) normally carries oxygen from the lungs to the tissues, anemia leads to hypoxia (lack of oxygen) in organs. Since all human cells depend on oxygen for survival, varying degrees of anemia can have a wide range of clinical consequences.
Anemia is the most common disorder of the blood. The
several kinds of anemia are produced by a variety of underlying causes. It can
be classified in a variety of ways, based on the morphology of RBCs, underlying
etiologic mechanisms, and discernible clinical spectra, to mention a few. The
three main classes include excessive blood loss (acutely such as a hemorrhage or chronically through low-volume loss), excessive
blood cell destruction (hemolysis) or deficient red blood cell production (ineffective hematopoiesis).
Of the two major approaches to diagnosis, the
"kinetic" approach involves evaluating production, destruction and
loss, and the "morphologic" approach groups anemia by red blood cell
size. The morphologic approach uses a quickly available and low-cost lab test
as its starting point (the MCV). On the other hand, focusing early on the question
of production may allow the clinician to expose cases more rapidly where
multiple causes of anemia coexist.
Signs and symptoms:
Main symptoms that may appear in anemia
Anemia goes undetermined in many people, and symptoms
can be minor or vague. The signs and symptoms can be related to the anemia
itself, or the underlying cause.
On examination, the signs exhibited may include pallor (pale skin, mucosal linings and nail beds), but this is not a reliable sign. There may be signs
of specific causes of anemia, e.g., koilonychia (in iron deficiency), jaundice (when anemia results from abnormal break down of red
blood cells — in hemolytic anemia), bone deformities (found in thalassemia
major) or leg ulcers (seen in sickle-cell
disease).
In severe anemia, there may be signs of a hyperdynamic circulation: tachycardia (a fast heart rate), bounding pulse, flow murmurs, and cardiac ventricular hypertrophy (enlargement). There may be signs of heart failure.
Pica, the consumption of non-food items such as soil, paper, wax, grass, ice, and hair, may be a symptom of iron deficiency, although it occurs often in those who have normal levels of hemoglobin.
In severe anemia, there may be signs of a hyperdynamic circulation: tachycardia (a fast heart rate), bounding pulse, flow murmurs, and cardiac ventricular hypertrophy (enlargement). There may be signs of heart failure.
Pica, the consumption of non-food items such as soil, paper, wax, grass, ice, and hair, may be a symptom of iron deficiency, although it occurs often in those who have normal levels of hemoglobin.
Chronic anemia may result in behavioral disturbances
in children as a direct result of impaired neurological development in infants,
and reduced scholastic performance in children of school age. Restless
legs syndrome is more common
in those with iron-deficiency
anemia.
LEUKEMIA
Is a type of cancer of the blood or bone marrow
characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum
of diseases. In turn, it is part of the even broader group of diseases affecting
the blood, bone marrow, and lymphoid system, which are all
known as hematological
neoplasms.
If the leukemic cells invade the central
nervous system, then
neurological symptoms (notably headaches) can occur. All symptoms associated with leukemia can
be attributed to other diseases. Consequently, leukemia is always diagnosed
through medical
tests. 
Often, low platelet levels do not
lead to clinical problems; rather, they are picked up on a routine full
blood count (or CBC,
complete blood count). Occasionally, there may be bruising, particularly purpura in the forearms, petechia (pinpoint hemorrhages on skin and mucous membranes), nosebleeds and/or bleeding gums.
It is vital that a full medical history is elicited to ensure the low platelet count is not due to a secondary process. It is also important to ensure that the other blood cell types, such as red blood cells and white blood cells, are not also suppressed. Painless, round and pinpoint (1 to 3 mm in diameter) petechiae usually appear and fade, and sometimes group to form ecchymoses. Larger than petechiae, ecchymoses are purple, blue or yellow-green bruises that vary in size and shape. They can occur anywhere on the body.
IRON IN THE BLOOD
An iron test checks the amount of
iron in the blood to see how well iron is metabolized in the body. Iron (Fe) is a
mineral needed for hemoglobin, the protein in red blood cells that carries oxygen. Iron is also needed for
energy, good muscle and organ function.
In 2000, approximately 256,000 children and adults
around the world developed some form of leukemia, and 209,000 died from it. About
90% of all leukemias are diagnosed in adults.
Signs and symptoms:
Common symptoms of chronic or acute leukemia
Damage to the bone marrow, by way of displacing the
normal bone marrow cells with higher numbers of immature white blood cells,
results in a lack of blood platelets, which are important in the blood
clotting process. This means
people with leukemia may easily become bruised, bleed excessively, or develop pinprick bleeds (petechiae).
White blood cells, which are involved in fighting pathogens, may be suppressed or dysfunctional. This could cause
the patient's immune system to be unable to fight off a simple infection or to
start attacking other body cells. Because leukemia prevents the immune system
from working normally, some patients experience frequent infection, ranging from infected tonsils, sores in the mouth, or diarrhea to life-threatening pneumonia or opportunistic
infections.
Some patients experience other symptoms, such as feeling sick, having fevers, chills, night sweats, feeling fatigued and other flu-like symptoms. Some patients experience nausea or a feeling of
fullness due to an enlarged liver and spleen; this can result in unintentional weight
loss. Blasts affected by the disease may come together and become
swollen in the liver or in the lymph nodes causing pain and leading to nausea.
The word leukemia, which means 'white blood',
is derived from the disease's namesake high white blood cell counts that most
leukemia patients have before treatment. The high number of white blood cells
are apparent when a blood sample is viewed under a microscope. Frequently,
these extra white blood cells are immature or dysfunctional. The excessive
number of cells can also interfere with the level of other cells, causing a
harmful imbalance in the blood count.
Some leukemia patients do not have high white blood cell counts visible during a regular blood count. This less-common condition is called aleukemia. The bone marrow still contains cancerous white blood cells which disrupt the normal production of blood cells, but they remain in the marrow instead of entering the bloodstream, where they would be visible in a blood test. For an aleukemic patient, the white blood cell counts in the bloodstream can be normal or low. Aleukemia can occur in any of the four major types of leukemia, and is particularly common in hairy cell leukemia.
Some leukemia patients do not have high white blood cell counts visible during a regular blood count. This less-common condition is called aleukemia. The bone marrow still contains cancerous white blood cells which disrupt the normal production of blood cells, but they remain in the marrow instead of entering the bloodstream, where they would be visible in a blood test. For an aleukemic patient, the white blood cell counts in the bloodstream can be normal or low. Aleukemia can occur in any of the four major types of leukemia, and is particularly common in hairy cell leukemia.
A normal human platelet count ranges from 150,000 to
450,000 platelets per microlitre of blood.[1] These limits are determined by the 2.5th lower and
upper percentile, so values outside this range do not necessarily
indicate disease. One common definition of thrombocytopenia is a platelet count
below 50,000 per microlitre.
Signs and symptoms:
It is vital that a full medical history is elicited to ensure the low platelet count is not due to a secondary process. It is also important to ensure that the other blood cell types, such as red blood cells and white blood cells, are not also suppressed. Painless, round and pinpoint (1 to 3 mm in diameter) petechiae usually appear and fade, and sometimes group to form ecchymoses. Larger than petechiae, ecchymoses are purple, blue or yellow-green bruises that vary in size and shape. They can occur anywhere on the body.
A person with thrombocytopenia may also complain of
malaise, fatigue and general weakness (with or without accompanying blood
loss). In acquired thrombocytopenia, the patient's history may include the use
of one or several offending drugs.
Inspection typically reveals evidence of bleeding
(petechiae or ecchymoses), along with slow, continuous bleeding from any
injuries or wounds. Adults may have large, blood-filled bullae in the mouth. If
the person's platelet count is between 30,000 and 50,000/mm3,
bruising with minor trauma may be expected; if it is between 15,000 and
30,000/mm3, spontaneous bruising will be seen (mostly on the arms
and legs).
IRON IN THE BLOOD
About 70% of the body's iron is bound to hemoglobin in
red blood cells. The rest is bound to other proteins (transferrin in
blood or ferritin in bone marrow) or stored in other body tissues. When
red blood cells die, their iron is released and carried by transferrin to the
bone marrow and to other organs such as the liver and spleen. In the bone marrow, iron is stored and used as
needed to make new red blood cells.
The source of all the body's iron is food, such as
liver and other meat, eggs, fish, and leafy green vegetables. The body needs
more iron at times of growth (such as during adolescence), for pregnancy, during breast-feeding, or at times when there are low levels of iron
in the body (such as after bleeding).
Healthy adult men get enough iron from the food they
eat. Men have enough reserves of iron in their bodies to last for several
years, even if they take in no new iron. Men rarely develop an iron deficiency
because of their diets. But women can lose large amounts of iron because of
menstrual bleeding, during pregnancy, or while breast-feeding. So women are
more likely than men to develop an iron deficiency and may need to take an iron
supplement. Iron deficiency in men and in women past menopause is often from abnormal bleeding, often in the
gastrointestinal tract, such as from stomach ulcers or colon cancer.
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