General Practice Flashcards

Which of the following conventional ECG leads allows you to see the heart's inferior wall?

Answer: aVF

The inferior wall of the heart is best viewed by the ECG leads II, III, and aVF. These leads are positioned to detect electrical activity from the inferior aspect of the heart. Lead aVF specifically stands for 'augmented vector foot' and provides a clear electrical perspective looking up from the foot towards the heart's inferior surface.

Which of the following current leakage tests does NOT meet IEC or NFPA 99 standards?

Answer: Machine leakage current

IEC 60601-1 and NFPA 99 standards specify several types of leakage current tests for medical electrical equipment, including Earth leakage current, Patient leakage current, and Chassis (or enclosure) leakage current. 'Machine leakage current' is not a recognized or standard term for leakage current testing within these international and national safety regulations.

Which of the following MOST accurately describes the hematocrit centrifuge's relative centrifugal force (RFC)?

Answer: 10,000 RCF

Hematocrit centrifuges are designed to rapidly separate blood components, requiring a high relative centrifugal force (RCF) to efficiently pack red blood cells. An RCF of approximately 10,000-12,000 G (or RCF) is typically used for accurate hematocrit determination, making 10,000 RCF the most appropriate and common value among the choices for this application.

What forces drive the kidneys' filtration?

Answer: Blood pressure

The primary force driving glomerular filtration in the kidneys is hydrostatic pressure, which is essentially the blood pressure within the glomerular capillaries. This pressure forces water and small solutes from the blood into Bowman's capsule, initiating the process of urine formation. Other forces like osmosis or muscle contraction play roles elsewhere in the urinary system but not in the initial filtration.

What may be measured with a digital multimeter's (DMM) continuity mode?

Answer: Total resistance between two points

A digital multimeter (DMM) in continuity mode is designed to detect if there is a complete electrical path between two points. It typically emits an audible tone if the resistance between the points is very low (indicating continuity) and often displays the resistance value. Therefore, it measures the total resistance, specifically looking for very low resistance to confirm a continuous path.

What is being looked at with an opthalmoscope?

Answer: Fundus

An ophthalmoscope is a medical device specifically designed to examine the interior of the eye, known as the fundus. The fundus includes critical structures like the retina, optic disc, macula, and blood vessels, allowing healthcare professionals to assess eye health and detect various ocular and systemic conditions.

In which of the following scenarios is a device fault more likely to occur than a use mistake?

Answer: A nurse station not receiving patient information from vital signs monitor

A nurse station not receiving patient information from a vital signs monitor strongly indicates a technical malfunction or device fault. This could be due to a communication error, network issue, or internal hardware problem with the monitor or the receiving system. The other scenarios are more likely attributable to user error or environmental factors rather than an inherent device fault.