MLT Chemistry Test

Human Chorionic gonadotropin (HCG) is secreted by the placenta and is used for the early detection of pregnancy. This hormone is produced by the developing placenta shortly after fertilization and can be detected in the blood or urine of pregnant women. HCG levels rise rapidly in the early stages of pregnancy and can be detected as early as 10 days after conception. Therefore, HCG is commonly used in pregnancy tests to determine if a woman is pregnant or not.

The middle value of a data set is statistically known as the median. The median is calculated by arranging the data set in ascending order and finding the value that falls exactly in the middle. It is a measure of central tendency that is not affected by extreme values or outliers in the data. The median is useful when the data set has a skewed distribution or contains outliers.

Rickets is a condition that is associated with a deficiency in vitamin D. Vitamin D is essential for the absorption of calcium and phosphorus in the body, which are important for bone health. A deficiency in vitamin D can lead to weakened and soft bones, causing rickets. Therefore, option D is the correct answer.

Parathyroid hormone is responsible for regulating the concentration of calcium in the serum. This hormone is produced by the parathyroid glands, which are located in the neck. When the calcium levels in the blood are low, the parathyroid glands release parathyroid hormone, which stimulates the release of calcium from the bones and increases the absorption of calcium from the intestines. This helps to maintain the balance of calcium in the body and ensure that it is available for important functions such as muscle contraction and nerve transmission.

Decreased serum iron levels and increased total iron-binding capacity (TIBC) are characteristic findings in iron deficiency anemia. Iron deficiency anemia occurs when there is insufficient iron to produce hemoglobin, leading to decreased red blood cell production and subsequent anemia. In this condition, the body tries to compensate by increasing TIBC, which reflects the amount of iron that can be bound and transported in the blood. Anemia of chronic infection, chronic liver disease, and nephrosis may also cause anemia, but they typically present with different iron-related laboratory findings.

When myocardial infarction occurs, the first enzyme to become elevated is CK (creatine kinase). CK is an enzyme found in the heart muscle, and its levels increase in the blood when there is damage to the heart muscle, such as during a heart attack. LD (lactate dehydrogenase), AST (aspartate aminotransferase), and ALT (alanine aminotransferase) are also enzymes that can indicate heart muscle damage, but CK is typically the first to become elevated.

AST and ALT are both enzymes that are found primarily in the liver. When the liver is damaged or inflamed, these enzymes are released into the bloodstream, causing their levels to increase. Viral hepatitis is a disease that specifically affects the liver, causing inflammation and damage. Therefore, it is expected to see elevated levels of AST and ALT in viral hepatitis. Muscular dystrophy, pulmonary emboli, and infectious mononucleosis do not primarily affect the liver, so elevated levels of AST and ALT would not be expected in these conditions.

Uric acid is the end product of purine metabolism in humans. Purines are nitrogenous bases found in DNA and RNA, as well as in other molecules such as ATP and GTP. When purines are broken down, they are converted into uric acid through a series of enzymatic reactions. Uric acid is then excreted from the body through urine. This process is important for maintaining the balance of purines in the body and preventing the buildup of excessive purine levels, which can lead to conditions such as gout.

Scurvy is a disease caused by a deficiency of vitamin C. Vitamin C is also known as ascorbic acid and is essential for the synthesis of collagen, a protein that helps in the formation of connective tissues, skin, blood vessels, and bones. A deficiency of vitamin C leads to symptoms like fatigue, weakness, joint pain, bleeding gums, and slow wound healing, which are characteristic of scurvy. Therefore, the correct answer is C, as scurvy is associated with a deficiency of vitamin C.

Glucose is the correct answer because it is a rapidly metabolized substance and can be broken down by enzymes present in the blood. When a blood specimen is left standing at room temperature for 8 hours, the metabolic activity in the blood continues, leading to a decrease in glucose levels. Therefore, glucose is unstable if left standing at room temperature for a prolonged period before processing.

The first step to be taken when attempting to repair a piece of electronic equipment is to turn the instrument off. This is important for safety reasons as it eliminates the risk of electric shock. By turning off the instrument, you ensure that there is no power running through it, reducing the chances of accidents or further damage. It also allows you to work on the equipment without any interference from electrical currents.

The statistical term for the average value is the mean. The mean is calculated by summing up all the values in a dataset and dividing it by the total number of values. It is commonly used to represent the central tendency of a set of data and provides a measure of the typical value.

Sodium fluoride inhibits glycolysis. Glycolysis is the process by which glucose is broken down to produce energy in the form of ATP. Sodium fluoride acts as an inhibitor of the enzyme enolase, which is involved in the glycolysis pathway. By inhibiting enolase, sodium fluoride disrupts the glycolysis process, leading to a decrease in ATP production.

The normal range for the pH of arterial blood measured at 37 degrees Celsius is 7.35-7.45. This range is considered normal because it reflects the optimal pH level for the body's metabolic processes to function properly. Any deviation from this range can indicate an imbalance in the body's acid-base balance, which may be a sign of an underlying health condition.

Sodium is the chief plasma cation that plays a crucial role in maintaining osmotic pressure. Osmotic pressure is the force that keeps fluids balanced inside and outside of cells. Sodium helps regulate fluid balance by attracting and retaining water in the bloodstream. It also aids in nerve function, muscle contraction, and maintaining blood pressure. Calcium, potassium, and chloride are also important electrolytes, but they do not have the same primary function as sodium in maintaining osmotic pressure.

A potassium level of 6.8 mEq/L is significantly high and could indicate hyperkalemia. However, before reporting the result, it is important to check the serum for hemolysis. Hemolysis, the breakdown of red blood cells, can falsely elevate potassium levels. By checking for hemolysis, the technologist can ensure the accuracy of the potassium level before reporting the result.

Cerebrospinal fluid should be analyzed immediately for glucose assay because glucose is a highly metabolized substance and its concentration can decrease rapidly over time. Delaying the analysis may result in inaccurate results as the glucose levels in the cerebrospinal fluid can decrease due to continued metabolism. Therefore, it is important to analyze the sample immediately to obtain reliable glucose measurements.

The osmolality of a urine or serum specimen is measured by a change in the freezing point. This is because the number of solute particles in a solution affects its freezing point. When solutes are present in a specimen, they lower the freezing point of the solution. By measuring the extent of this change in freezing point, the osmolality of the specimen can be determined.

Acetaminophen is an analgesic that is commonly used to relieve pain and reduce fever. Unlike other analgesics, such as opioids, acetaminophen does not cause loss of consciousness or sedation. It works by inhibiting the production of certain chemicals in the body that are involved in pain and fever. Therefore, acetaminophen is a suitable option for individuals who need pain relief but do not want to experience the side effects of sedation or loss of consciousness.

Sodium is the major cation in extracellular fluid and plays a crucial role in maintaining osmotic balance. It contributes significantly to serum osmolality, which is a measure of the concentration of solutes in the blood. Glucose, chloride, and urea also contribute to osmolality, but sodium has the greatest impact.

Night blindness is associated with deficiency of vitamin A. Vitamin A is essential for the proper functioning of the retina, which is responsible for vision in low light conditions. Deficiency of vitamin A can impair the adaptation of the eyes to darkness, leading to night blindness.

Lithium is a carbonate salt that is commonly used to control manic-depressive disorders, also known as bipolar disorder. It helps to stabilize mood swings and reduce the severity of manic and depressive episodes. Digoxin is a medication used to treat heart conditions, acetaminophen is a pain reliever, and phenytoin is an anti-seizure medication. Therefore, lithium is the correct answer for this question.

Corticosterone is an adrenal cortical hormone. It is produced by the adrenal cortex and plays a role in regulating various physiological processes in the body, including metabolism, immune response, and stress response. It is classified as a glucocorticoid, which means it helps regulate glucose levels in the body. Corticosterone is also involved in the body's response to inflammation and helps suppress the immune system when necessary. Therefore, corticosterone is the correct answer as it is a steroid hormone produced by the adrenal cortex.

The higher morning value of plasma cortisol compared to the evening concentration is a normal finding. This is because cortisol levels naturally fluctuate throughout the day, with the highest levels occurring in the morning and the lowest levels in the evening. This pattern is known as diurnal variation and is a normal physiological response. Therefore, the laboratory results indicating a higher morning value are within the expected range and do not suggest any abnormality or disease.

The majority of carbon dioxide in the blood is transported in the form of bicarbonate ions. When carbon dioxide diffuses into red blood cells, it combines with water to form carbonic acid. Carbonic acid then dissociates into bicarbonate ions and hydrogen ions. The bicarbonate ions are transported in the plasma, while the hydrogen ions bind to hemoglobin. This bicarbonate ion transport mechanism helps maintain the acid-base balance in the body.

Testosterone is the correct answer because it is the most biologically active, naturally occurring androgen. It is produced in the testes in males and in smaller amounts in the ovaries and adrenal glands in females. Testosterone plays a crucial role in the development and maintenance of male reproductive tissues and secondary sexual characteristics. It is also involved in various physiological processes such as muscle growth, bone density, and red blood cell production.

Urea is the correct answer because it is the main excretory form of nitrogen in mammals. It is produced in the liver as a result of the breakdown of amino acids and is then transported to the kidneys for excretion in urine. Urea is less toxic than other nitrogenous waste products such as uric acid and creatinine, making it the preferred form of nitrogen excretion in mammals.

The biuret reaction is a chemical test used to detect the presence of peptide bonds in proteins. It involves the reaction of copper ions with the peptide bonds, resulting in a color change from blue to purple. Therefore, the number of peptide bonds present in a protein sample determines the intensity of the color change, making peptide bonds the key factor in the biuret reaction for the analysis of serum protein. Free amino acids, free carboxyl groups, and tyrosine residues are not directly involved in this reaction.

Fluorometry is a technique that involves the measurement of fluorescence, which occurs when a compound absorbs light at one wavelength and emits light at a different wavelength. This statement accurately describes the concept of fluorescence. The other statements are not true. Detectors in fluorometers are typically placed at a 90-degree angle from the excitation source, not 180 degrees. Fluorometry is actually more sensitive than spectrophotometry because it can detect lower concentrations of compounds. Finally, complexing of components may still be necessary in fluorometry depending on the specific experiment or analysis being conducted.

Accuracy refers to the extent to which measurements agree with the true value of the quantity being measured. It indicates how close the measured value is to the actual or accepted value. Reliability refers to the consistency or repeatability of measurements, while reproducibility refers to the ability to obtain the same results when an experiment is repeated. Precision refers to the level of detail or exactness in a measurement, regardless of its accuracy.

The anion gap is useful for quality control (QC) of laboratory results for sodium, potassium, chloride, and total CO2. The anion gap is calculated by subtracting the sum of the measured anions (chloride and total CO2) from the sum of the measured cations (sodium and potassium). It helps to ensure that the electrolyte levels are correctly measured and balanced in the body. By monitoring the anion gap, any discrepancies or errors in the laboratory results can be identified and corrected, thus improving the accuracy and reliability of the tests.

The regulation of calcium and phosphorus metabolism is accomplished by the parathyroid glands. These small glands are located in the neck, behind the thyroid gland. They produce parathyroid hormone (PTH), which helps to regulate the levels of calcium and phosphorus in the blood. PTH acts on the bones, kidneys, and intestines to increase calcium levels when they are too low. It does this by promoting the release of calcium from the bones, increasing the reabsorption of calcium in the kidneys, and enhancing the absorption of calcium from the intestines. Therefore, the parathyroid glands play a crucial role in maintaining the balance of calcium and phosphorus in the body.

Total iron-binding capacity (TIBC) measures the serum iron transporting capacity. Transferrin is a protein in the blood that binds to iron and transports it throughout the body. TIBC is a measure of how much transferrin is available to bind with iron. Therefore, the correct answer is Transferrin.

Hyperventilation is a common cause of respiratory alkalosis. When a person hyperventilates, they breathe rapidly and shallowly, leading to a decrease in carbon dioxide levels in the blood. This results in a shift towards alkalinity in the body's pH balance, causing respiratory alkalosis. Hyperventilation can be triggered by anxiety, panic attacks, or certain medical conditions.

A hospitalized patient experiencing increased neuromuscular irritability (tetany) should have their calcium levels tested immediately. Tetany is often caused by low levels of calcium in the blood, which can lead to muscle spasms and twitching. By ordering a calcium test, healthcare providers can determine if the patient's tetany is due to hypocalcemia and take appropriate measures to correct it. The other tests listed (phosphorus, BUN, and glucose) may be important in certain clinical situations, but they are not as directly related to the symptoms of tetany as calcium.

Lithium therapy is widely used in the treatment of manic-depression, also known as bipolar disorder. This disorder is characterized by extreme mood swings, ranging from manic episodes of elevated mood, increased energy, and impulsive behavior, to depressive episodes of low mood, decreased energy, and feelings of hopelessness. Lithium is a mood stabilizer that helps to regulate these mood swings and prevent the recurrence of manic and depressive episodes. It is considered one of the most effective treatments for bipolar disorder and is commonly prescribed in combination with other medications and therapy.

The measurement of total T4 by competitive protein binding or displacement is based on the specific binding properties of thyroxine-binding globulin. Thyroxine-binding globulin is a protein in the blood that binds to thyroxine (T4) and carries it throughout the body. By measuring the amount of T4 that is bound to thyroxine-binding globulin, the total T4 level can be determined. This measurement is important in assessing thyroid function and diagnosing thyroid disorders.

In the Jaffe reaction, creatinine reacts with alkaline picrate solution to yield an orange-red complex. This reaction is commonly used to measure the concentration of creatinine in biological samples. When creatinine reacts with alkaline picrate solution, it forms a colored complex that can be measured spectrophotometrically. The intensity of the color is directly proportional to the concentration of creatinine in the sample, allowing for accurate quantification. Therefore, the correct answer is alkaline picrate solution to yield an orange-red complex.

Bile acid concentrations are useful to assess hepatobiliary disease because the liver produces bile acids, and any dysfunction or damage to the liver can affect the production and excretion of bile acids. Elevated levels of bile acids can indicate liver disease or obstruction in the bile ducts. By measuring bile acid concentrations, healthcare professionals can evaluate the functioning of the liver and diagnose hepatobiliary diseases such as liver cirrhosis, hepatitis, or cholestasis.

Triglyceride levels are expected to be falsely elevated on a serum specimen from a nonfasting patient because triglycerides are affected by recent food intake. When a person consumes food, especially fatty foods, triglyceride levels in the blood increase. Therefore, if a patient has recently eaten before the blood sample was taken, their triglyceride levels may be higher than they would be if they had fasted. In contrast, cholesterol, HDL, and LDL levels are not significantly affected by recent food intake, so they would not be expected to be falsely elevated in a nonfasting patient.

Blood PCO2 can be measured by calculating the blood pH and total CO2 concentration. This is because the PCO2 value is indirectly related to the blood pH and total CO2 concentration. By measuring the blood pH and total CO2 concentration, the PCO2 level can be estimated using various equations and calculations. This method is commonly used in clinical settings to assess the acid-base balance and respiratory function of a patient.

Glycolysis is the correct answer because it is the process of converting glucose or other hexoses into lactate or pyruvate. During glycolysis, glucose is broken down into two molecules of pyruvate, which can then be further metabolized to produce energy. This process occurs in the cytoplasm of cells and is an important step in both aerobic and anaerobic respiration. Glycogenesis, glycogenolysis, and gluconeogenesis are all different processes involved in the regulation of glucose metabolism, but they are not specifically related to the conversion of glucose into lactate or pyruvate.

The greatest activities of serum AST (aspartate aminotransferase) and ALT (alanine aminotransferase) are seen in acute hepatitis. AST and ALT are enzymes that are primarily found in liver cells. When liver cells are damaged or inflamed, these enzymes are released into the bloodstream, leading to increased levels of AST and ALT in the serum. Acute hepatitis is characterized by inflammation of the liver, which causes liver cell damage and subsequent release of AST and ALT into the bloodstream. Therefore, acute hepatitis would result in the highest levels of serum AST and ALT compared to the other conditions listed.

Arterial blood gases (ABGs) are time-sensitive tests that provide information about a patient's respiratory and metabolic status. The delay of 2.5 hours from the time of collection to receipt in the laboratory can significantly alter the results of the ABG analysis. The technologist should request a new arterial specimen to be obtained to ensure accurate and reliable results.

Blood gas determination requires accurate measurement of pH, pO2, and pCO2 levels in the blood. Heparin is commonly used as an anticoagulant in blood gas samples because it prevents clotting and preserves the integrity of the blood gases. No preservatives, EDTA, and oxalate are not suitable for blood gas determination as they can interfere with the accuracy of the results.

The most frequent value in a collection of data is known as the mode. The mode is the value that appears the most number of times in the data set. It is a measure of central tendency and is used to describe the typical or most common value in the data. Unlike the mean and median, the mode does not consider the magnitude of the values, only their frequency of occurrence. Therefore, the mode is the correct answer in this case.

Digoxin is a cardiac glycoside that is commonly used in the treatment of congenital heart failure and arrhythmias. It works by increasing the force and velocity of myocardial contraction, which helps to improve cardiac output and reduce symptoms of heart failure. Digoxin achieves this by inhibiting the sodium-potassium ATPase pump, leading to an increase in intracellular calcium levels. This increase in calcium enhances the contractility of the heart muscle, resulting in a stronger and more efficient heartbeat. Therefore, Digoxin is the correct answer for this question.

Acidosis and alkalosis refer to imbalances in blood pH and CO2 content. The bicarbonate buffer system plays a crucial role in maintaining the pH balance in the blood. It consists of bicarbonate ions (HCO3-) and carbonic acid (H2CO3), which can either accept or donate hydrogen ions (H+). When there is an excess of acid in the blood, the bicarbonate ions act as a base and bind with the hydrogen ions, helping to neutralize the acidity. Conversely, when there is an excess of base in the blood, the carbonic acid can release hydrogen ions, helping to restore the pH balance. Therefore, changes in the bicarbonate buffer system can lead to fluctuations in blood pH and CO2 content, resulting in acidosis or alkalosis.

Respiratory acidosis is a condition characterized by an increase in carbon dioxide (CO2) content and partial pressure of carbon dioxide (PCO2) in the blood, leading to a decrease in pH. This occurs when the lungs are unable to effectively remove CO2 from the body, causing it to accumulate in the bloodstream. The increased CO2 levels result in the production of carbonic acid, which lowers the pH of the blood, leading to acidosis. Therefore, the correct answer is an increase in CO2 content and PCO2 with a decreased pH.

Amylase is the correct answer because it is an enzyme that catalyzes the breakdown of starch into glucose and maltose. Starch is a complex carbohydrate made up of many glucose molecules linked together, and amylase helps to break these bonds, converting starch into simpler sugars like glucose and maltose. Malate dehydrogenase, creatine kinase, and isocitric dehydrogenase are enzymes involved in other metabolic processes and are not directly responsible for the conversion of starch to glucose and maltose.