The arterial blood gas below indicates that the primary acid-base imbalance is:

pH - 7.25

PaCO2 - 20 mm Hg

HCO3- - 10 mEq/L

Select all that apply:

Normal range:

pH = 7.35-7.45

PaCO2 = 36-44 mmHg

HCO3- = 22-26 mEq/L

Choice A Reason:

The exhaustion stage is the final phase of the general adaptation syndrome (GAS). It occurs when the body has been exposed to stress for a prolonged period and can no longer maintain resistance. Symptoms of exhaustion include fatigue, burnout, depression, and decreased stress tolerance. Since the student is experiencing an immediate response to a sudden stressor, this stage does not apply.

Choice B Reason:

Adaptation is not a specific stage in the general adaptation syndrome. The correct stages are alarm, resistance, and exhaustion. Therefore, this choice is incorrect.

Choice C Reason:

This is the correct answer. The alarm stage is the initial phase of the general adaptation syndrome, also known as the “fight-or-flight” response. During this stage, the body reacts to a stressor by activating the sympathetic nervous system, which leads to increased heart rate, rapid breathing, and heightened alertness. The student’s reaction to the near-miss accident fits this description perfectly.

Choice D Reason:

The stage of resistance is the second phase of the general adaptation syndrome. During this stage, the body attempts to adapt to the stressor and return to a state of balance. If the stressor persists, the body remains on high alert, but the initial shock of the alarm stage has passed. Since the student’s response is immediate and acute, it aligns with the alarm stage rather than the resistance stage.

Choice A Reason:

Decreased ATP production is the primary cause of sodium and water accumulation in an injured cell. ATP is essential for the function of the sodium-potassium (Na±K+) pump, which maintains the ionic balance within the cell. When ATP levels drop, the Na±K+ pump fails, leading to an influx of sodium and water into the cell, causing cellular swelling.

Choice B Reason:

Calcification of the cell refers to the abnormal deposition of calcium salts within the cell. While calcification can occur in injured cells, it is not directly responsible for sodium and water accumulation. Calcification is more related to chronic injury and cell death rather than acute cellular swelling.

Choice C Reason:

Ribosome detachment from the endoplasmic reticulum can occur due to cellular stress and injury, leading to reduced protein synthesis. However, this detachment is not the direct cause of sodium and water accumulation. The primary issue is the failure of the Na±K+ pump due to decreased ATP production.

Choice D Reason:

Dehydration refers to the loss of water from the body or cells. While dehydration can affect cellular function, it is not the cause of sodium and water accumulation in injured cells. The accumulation is primarily due to the failure of the Na±K+ pump, which is dependent on ATP.