Final answer:
The pCO2 at the arterial end of a tissue capillary is approximately 45 mm Hg.
Step-by-step explanation:
At the arterial end of a tissue capillary, the pCO₂ (partial pressure of carbon dioxide) would be approximately 45 mm Hg. As blood travels from the lungs to the tissues, carbon dioxide is produced through cellular respiration. This causes the partial pressure of carbon dioxide in the tissues to be higher than in the blood, resulting in the diffusion of carbon dioxide out of the tissue cells and into the capillaries.