Human Anatomy and Physiology : Help with Heart Injuries and Disorders

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #11 : Help With Heart Injuries And Disorders

Hyperkalemia will most commonly cause what type of change to an ECG recording of the heart?

Possible Answers:

Peaked P-waves

Flattened T-waves

Prolonged P-R interval

Peaked T-waves

Short P-R interval

Correct answer:

Peaked T-waves

Explanation:

The correct answer is peaked T-waves. The T-wave of an ECG reading corresponds to repolarization of the cardiac muscle after a ventricular contraction. Cardiomyocytes establish their repolarization through the influx of potassium during the T-wave. If potassium is elevated within the blood (i.e. hyperkalemia), this T-wave reading will be exaggerated due to the excessive influx of potassium into the cardiac cells.

Example Question #12 : Help With Heart Injuries And Disorders

A 45 year old male with a history of hypertension (high blood pressure) and diabetes reports to the emergency room with three hours of chest pain. He is found to have a myocardial infarction as evidenced by EKG tracings. Which of the following laboratory tests is likely to be elevated in this patient?

Possible Answers:

Calcium

Sodium

Potassium

Troponin

Blood urea nitrogen

Correct answer:

Troponin

Explanation:

Elevations in troponins are diagnostic for a myocardial infarction (heart attack). Troponin is a protein released into circulation from cardiac myocytes when they die from lack of oxygen. The other laboratory values are not affected by myocardial death.

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