CLS Clinical Chemistry 2

Question 1

Which thyroid function test is considered the most sensitive initial screening test for thyroid disorders?

Accepted Answer

Thyroid-stimulating hormone (TSH)

Answer

TSH is the most sensitive initial screening test because small changes in thyroid hormone levels trigger large compensatory changes in TSH secretion.

Question 2

A patient has elevated AST and ALT with a De Ritis ratio (AST/ALT) greater than 2:1. This pattern is most consistent with which condition?

Accepted Answer

Alcoholic liver disease

Answer

An AST/ALT ratio greater than 2:1 is characteristic of alcoholic liver disease because alcohol and its metabolites selectively damage mitochondria, elevating AST disproportionately.

Question 3

Which analyte is measured to assess pancreatic exocrine function and is elevated in acute pancreatitis?

Accepted Answer

Lipase and amylase

Answer

Lipase and amylase are pancreatic enzymes released into the bloodstream during acute pancreatitis, with lipase being more specific and remaining elevated longer.

Question 4

In a patient with metabolic acidosis, which finding would indicate respiratory compensation?

Accepted Answer

Decreased PCO2 below 40 mmHg

Answer

In metabolic acidosis, the respiratory system compensates by hyperventilating to blow off CO2, resulting in a decreased PCO2.

Question 5

Which protein is measured to assess long-term glycemic control over approximately 2-3 months?

Accepted Answer

Glycated hemoglobin (HbA1c)

Answer

HbA1c reflects average blood glucose over the preceding 2-3 months, correlating with the lifespan of red blood cells.

CLS - Certified Laboratory Professional Practice Test

CLS - Certified Laboratory Professional Practice Test

CLS Clinical Chemistry 2