Question

Which of the following statement(s) about pulse oximetry is/are TRUE?

• A. Oxygenated hemoglobin absorbs less infrared light (900 nm) compared to deoxygenated hemoglobin
• B. Oxygenated hemoglobin absorbs less visible light (600 nm) compared to deoxygenated hemoglobin
• C. Oxygenated hemoglobin absorbs more visible light (600 nm) compared to deoxygenated hemoglobin
• D. Oxygenated hemoglobin absorbs more infrared light (900 nm) compared to deoxygenated hemoglobin

Hint:

In pulse oximetry, two wavelengths of light (usually one in the visible and one in the infrared range) are used to differentiate between oxygenated and deoxygenated hemoglobin based on their absorption properties at these wavelengths.

Answer 1

The Correct Option is B, D

(A) Oxygenated hemoglobin absorbs less infrared light (900 nm) compared to deoxygenated hemoglobin
This statement is false. Oxygenated hemoglobin absorbs more infrared light (900 nm) compared to deoxygenated hemoglobin. Infrared light is absorbed more by oxygenated hemoglobin than by deoxygenated hemoglobin.
(B) Oxygenated hemoglobin absorbs less visible light (600 nm) compared to deoxygenated hemoglobin
This statement is true. Oxygenated hemoglobin absorbs less visible light (600 nm) compared to deoxygenated hemoglobin. Visible light is absorbed more by deoxygenated hemoglobin, which is why pulse oximeters use this wavelength to determine oxygen saturation.
(C) Oxygenated hemoglobin absorbs more visible light (600 nm) compared to deoxygenated hemoglobin
This statement is false. As mentioned earlier, oxygenated hemoglobin absorbs less visible light (600 nm) compared to deoxygenated hemoglobin.
(D) Oxygenated hemoglobin absorbs more infrared light (900 nm) compared to deoxygenated hemoglobin
This statement is true. Oxygenated hemoglobin absorbs more infrared light at 900 nm, which is used in pulse oximetry to determine oxygen saturation levels in the blood.