The partial pressure of oxygen in systemic tissue cells is approximately:Question 9Select one:a.40 mm Hg.b.45 mm Hg.c.105 mm Hg.d.70 mm Hg.e.100 mm Hg.

To determine the partial pressure of oxygen in systemic tissue cells, we need to understand the typical values found in the human body. The partial pressure of oxygen (pO2) in systemic arterial blood is usually around 100 mm Hg. However, as oxygen is delivered to tissues and used for cellular respiration, the pO2 decreases.

In systemic tissue cells, the partial pressure of oxygen is significantly lower than in arterial blood. This lower pressure facilitates the diffusion of oxygen from the blood into the tissues.

Let's evaluate the given options:

a. 40 mm Hg b. 45 mm Hg c. 105 mm Hg d. 70 mm Hg e. 100 mm Hg

Given that the partial pressure of oxygen in systemic tissue cells is lower than in arterial blood, options c (105 mm Hg) and e (100 mm Hg) can be ruled out because they are too high.

Option d (70 mm Hg) is also higher than the typical range for systemic tissue cells.

Between options a (40 mm Hg) and b (45 mm Hg), the more accurate value is around 40 mm Hg, which is a commonly accepted value for the partial pressure of oxygen in systemic tissue cells.

Therefore, the correct answer is:

a. 40 mm Hg.