What is the primary mechanism by which hemoglobin releases oxygen to tissues?

A Increased affinity for oxygen due to increased pH
B Decreased affinity for oxygen due to increased CO2 and decreased pH ✓
C Increased affinity for oxygen due to decreased temperature
D Decreased affinity for oxygen due to increased temperature

Explanation

Hemoglobin releases oxygen to tissues through the Bohr effect, where increased CO2 and decreased pH (more acidic conditions) decrease hemoglobin's affinity for oxygen, facilitating its release.

Mnemonic

Bohr effect: 'Bohr' sounds like 'bore' - CO2 'bores' into hemoglobin, decreasing its oxygen affinity

Source

Guyton and Hall Textbook of Medical Physiology
Hematology Hematology: Hemoglobin and Oxygen Transport Hematology: Hemoglobin and Oxygen Transport Medium MEDICAL Confidence: high