“Communicable Diseases Nurse Test” plus 4 more nursing article(s): NursingCrib.com Updates | ![]() |
- Communicable Diseases Nurse Test
- Erythropoiesis
- Congenital Heart Disorders – Disorders with Obstruction to Blood Flow
- Congenital Heart Disorders – Disorders with Mixed Blood Flow
- Congenital Heart Disorders – Disorders with Increase Pulmonary Blood Flow
Communicable Diseases Nurse Test Posted: 03 Dec 2010 06:12 PM PST December 2010 Nursing Board Exam Review Questions on Communicable Diseases. Mark the letter of your choice then click on the next button. Your score will be posted as soon as the you are done with the quiz. We will be posting more of this soon. Please be informed that the December 2010 Nursing Board Exam Results will be posted here in NursingCrib.com as soon as the PRC has released the official list of successful examinees. It is highly recommended to subscribe on our mailing list to get a copy of the result via email. Related posts:
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Posted: 03 Dec 2010 04:57 PM PST Red Blood Cells (RBC's) also called erythrocytes, are oxygen carrying cells. It is derived from the Greek words "erythros" meaning "red," "kytos" meaning "hollow" and "cyte" translated as "cell" in modern language. These cells are anuclaeted (without nucleus) and contain hemoglobin. Hemoglobin is the iron-containing component of the RBC and is responsible for oxygen transport. Site of RBC Production Erythrocytes are produced in the red marrow, a process known as ERYTHROPOIESIS. Red marrow is the site of active blood cell production and constitutes as the major blood-producing organ. This organ is highly vascular and it consists of connective tissues that contain free cells. The simplest structures of free cells are called stem cells. The stem cells are the precursor of two different cell lines namely:
Red Blood Cell Production The kidney is responsible for initiating the red blood cell production. Juxtaglomerular cells are present inside the kidneys. These cells are sensitive to the levels of oxygen in the blood. Low levels of oxygen detected in the blood (hypoxemia) delivered in the renal arterial supply stimulates the juxtaglomerular cells in the kidney to release erythrogenin. Erythrogenin is a renal erythropoietic factor that stimulates the kidney to form, produce and release the very important hormone in red blood cell production, erythropoietin (EPO). Erythropoietin is the hormone that stimulates red blood cell production in the red marrow. Mature red blood cells are formed from stem cells in the bone marrow. With the presence of erythropoietin, red cell pathway starts to form proerythroblast from stem cells. At this point the cell still contains nucleus. However, as the development progresses the nucleus becomes smaller and the cytoplasm becomes basophilic due to the presence of ribosome, thus the cell is now called basophilic erythroblast. As the cell becomes older it also becomes smaller and eventually when it begins to produce hemoglobin it is now termed as polychromatic erythroblast. Later on the cytoplasm will become more eosinophilic and the cell is now called orthochromatic erythroblast, which will then extrude its nucleus as the cells slowly fill with hemoglobin before entering the circulation as reticulocytes. Reticulocytes will mature to form the anucleated red blood cells. Final reticulocyte maturation takes place in the bloodstream. Within a few days the reticulocytes completely loses all its nuclear components and becomes a mature red blood cell. In a blood sample, reticulocytes can be differentiated from RBC's because the former still contain flecks of their nucleus. The lifespan of a fully mature RBC is 4 months or 120 days. After this period, the old and damaged RBCs are removed from the circulation by macrophages in the spleen and liver. Dietary Requirements Dietary elements are essential for RBC production. The following are needed by the red marrow to produce erythrocytes:
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Congenital Heart Disorders – Disorders with Obstruction to Blood Flow Posted: 03 Dec 2010 04:55 PM PST Disorders with Obstruction to Blood Flow Obstruction to the blood flow in the heart may be caused by narrowing of vessels or valves. As a result, the pressure before the narrowed part increased while it decreases after the narrowed area. This prevents the heart from reaching the lungs for oxygenation or the rest of the body. Disorders under this category include pulmonary stenosis, aortic stenosis and coarction of aorta. These heart diseases can cause back-pressure of the heart thereby overwhelming it. The word stenosis means narrowing of a specific part. Pulmonary stenosis is the narrowing of the pulmonary valve or the pulmonary artery itself distal to the valve. The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. A pulmonary valve is a flap of tissue that opens with pressure to allow blood to enter the pulmonary circulation. Inability of the right ventricle to evacuate blood to the pulmonary artery would result to right ventricular hypertrophy. Clinical Manifestations Some infants with pulmonary stenosis may be asymptomatic or have mild signs of right –sided heart failure. Severe narrowing of the pulmonary artery may cause the following manifestations:
Oxygenated blood is pumped from the left ventricle to the aorta. Presence of a stricture or stenosed aortic valve prevents blood from flowing to the systemic circulation. The heart's inability to evacuate blood in the left ventricle results to increased pressure and hypertrophy of the left ventricle. If the left ventricle's pressure becomes acute, pressure in the left atrium increases that would result to back-pressure in the pulmonary veins and possible pulmonary edema. Clinical Manifestations Most infants are asymptomatic however generally they present the following physical manifestation:
For severe cases
The narrowing of the lumen of aorta is a congenital heart failure called coarction of aorta. There are two types of this disorder:
Difficulty of the blood to enter the systemic circulation through narrowed aorta result to increase the blood pressure before (proximal) the coarction and decreased distal to it. Clinical Manifestations
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Congenital Heart Disorders – Disorders with Mixed Blood Flow Posted: 03 Dec 2010 04:50 PM PST Disorders with Mixed Blood Flow Mixing of the blood from the pulmonary and systemic circulation in the chambers of the heart results in a relative deoxygenation of the blood flowing. The defects under this include transposition of the great arteries, total anomalous pulmonary venous return, truncus arteriosus and hypoplastic left heart syndrome. Transposition of the Great Arteries Normally, the pulmonary artery arises from the right ventricle and the aorta from the left ventricle. With transposition of the great arteries, the pulmonary artery arises from the left ventricle while the aorta from the right ventricle. As blood (unoxygenated) enters the right atrium it flows to the right ventricle. Because the aorta is connected to the right ventricular portion of the heart completely deoxygenated blood goes out into the aorta to the different parts of the body. On the other side of the heart oxygenated blood enters the left atrium via the pulmonary veins. It flows to the left ventricle then back to the pulmonary artery then to the lungs and returns to the left atrium. Two closed circulatory systems are present. In most cases, ASD and VSD are present with transposition of the great arteries. This makes the entire heart have a single yet mixed circulation. Clinical Manifestations
Total Anomalous Pulmonary Venous Return Normally, the pulmonary vein drains oxygenated blood to the left atrium. In total anomalous pulmonary venous return, the pulmonary veins drain the blood to the right atrium or the superior vena cava. Blood from the right atrium enters the right ventricle to the pulmonary artery, lungs, pulmonary veins and back to the right atrium. Often, an absent spleen is associated with this disorder. Truncus Arteriosus Normally aorta and pulmonary artery are separate vessels. In Truncus Arteriosus, one major artery or trunk serves as the common pathway for the pulmonary artery and aorta. This trunk or major artery arises from the right and the left ventricles. Thus, Hypoplastic Left Heart Syndrome In Hypoplastic left heart syndrome, the left side of the heart is non-functional. The left ventricle, which pumps blood to the systemic circulation, lacks sufficient strength to pump the blood into the systemic circulation. This results to the hypertrophy of the right ventricle as it tries to maintain the adequate heart function and action. images from healthguide.howstuffworks.com, chw.org, health.allrefer.com Related posts:
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Congenital Heart Disorders – Disorders with Increase Pulmonary Blood Flow Posted: 03 Dec 2010 04:47 PM PST Classification of Congenital Heart Diseases Congenital Heart disorders were formerly classified as either cyanotic and acyanotic heart diseases. Cyanotic heart diseases occur when deoxygenated blood is shunted from the venous circulation to the arterial circulation, resulting to the bluish discoloration of the skin (cyanosis) due to decreased oxygen levels in the systemic circulation. With this classification, blood is shunted directly from the right to the left part of the heart. Acyanotic heart diseases involve narrowing or stricture of the blood that moves the blood from the arterial to the venous circulation (left to right shunt). However, some patients with heart diseases under the cyanotic type do not show cyanosis until they are seriously ill. And those with cyanotic heart diseases can also exhibit cyanosis. Because of the confusion the former system created a second classification system has been established. This classification system identifies four types of disorders which is classified according to the blood flow patterns of the disease not their signs and symptoms. The following are:
Disorders with Increased Pulmonary Blood Flow Congenital heart disorders classified with increased pulmonary blood flow follows the movement pattern of the blood from the left side of the heart (greater pressure) to the right side of the heart (lower pressure). This abnormal blood movement is due to an opening between two systems or arteries. Disorders of this type include the following:
With this cardiovascular defect, an opening between the two ventricles is present. Because pressure in the left side of the heart is greater than the right side, blood will be shunted from the left to the right. Thus, more blood enters the pulmonary circulation (from the right side) and less to the aorta. Clinical Manifestations:
Presence of an opening in between the two atria resulting to the shunt of the oxygenated blood from the left side of the heart to the right side is noted with ASD. This congenital heart disease is more common in girls than boys. Clinical Manifestations:
Endocardial cushion is the septum of the heart at the junction of the atrium and ventricle. When this endocardial cushion fails to fuse the disorder is called AVC or Endocardial Cushion Defect.
Ductus arteriosus is a fetal accessory that links the pulmonary artery to the aorta. Failure of this accessory structure to close at birth (Patent Ductus Arteriosus) will result to the shunting of the oxygenated blood from the aorta to the pulmonary artery. Clinical Manifestations:
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