Which factor is NOT typically listed as affecting oxygen delivery to tissues?

Which factor is NOT typically listed as affecting oxygen delivery to tissues?

• A. Altitude
• B. Heart Rate
• C. Toxic Gases
• D. G-Forces

Answer: (B)

Oxygen delivery to tissues depends on two main things: how much oxygen is carried in the arterial blood (CaO2) and how much blood is being pumped to deliver that oxygen (cardiac output). Altitude reduces the oxygen content of inspired air, so CaO2 drops. Toxic gases can bind hemoglobin or otherwise impair oxygen transport, also lowering CaO2. G-forces can distort blood flow distribution and perfusion, reducing the effective delivery to tissues. Heart rate is part of cardiac output, but on its own it isn’t usually listed as an independent factor affecting oxygen delivery; it’s the combination of heart rate and stroke volume (cardiac output) that determines DO2. So heart rate is not typically cited as a separate factor influencing tissue oxygen delivery.

Oxygen delivery to tissues depends on two main things: how much oxygen is carried in the arterial blood (CaO2) and how much blood is being pumped to deliver that oxygen (cardiac output). Altitude reduces the oxygen content of inspired air, so CaO2 drops. Toxic gases can bind hemoglobin or otherwise impair oxygen transport, also lowering CaO2. G-forces can distort blood flow distribution and perfusion, reducing the effective delivery to tissues. Heart rate is part of cardiac output, but on its own it isn’t usually listed as an independent factor affecting oxygen delivery; it’s the combination of heart rate and stroke volume (cardiac output) that determines DO2. So heart rate is not typically cited as a separate factor influencing tissue oxygen delivery.