Correct Answer: D

Rationale: This is incorrect because over-hydration is unlikely in a dehydrated patient. Overhydration is a condition where the body has too much water, which can cause hyponatremia, edema, and cerebral swelling. This is incorrect because diarrhea is a cause, not a consequence, of dehydration. Diarrhea is the frequent and watery passage of stool, which can lead to fluid and electrolyte loss. This is incorrect because pulmonary congestion is also unlikely in a dehydrated patient. Pulmonary congestion is a condition where the lungs are filled with fluid, which can cause dyspnea, cough, and crackles. This is correct because fall is a potential complication of dehydration. Dehydration can cause confusion, dizziness, weakness, and hypotension, which can increase the risk of falling and injuring oneself.

Correct Answer: C

Rationale: This is incorrect because diffusion is the movement of solutes (dissolved substances) from an area of higher concentration to an area of lower concentration, until equilibrium is reached. This is incorrect because hydrostatic pressure is the force exerted by a fluid against a wall or a membrane. Hydrostatic pressure can drive the movement of fluid and solutes across a membrane, but it is not the movement itself. This is correct because osmosis is the movement of a pure solvent (liquid) across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration, until equilibrium is reached. This is incorrect because ATP is not a movement, but a molecule. ATP stands for adenosine triphosphate, which is the main source of energy for cellular processes. ATP can provide energy for some types of transport across membranes, such as active transport.

Correct Answer: A

Rationale: This is correct because an electrolyte is a mineral or salt that dissolves in the body fluids and dissociates into ions, which can conduct electricity and perform various physiological functions.

Correct Answer: C

Rationale: This is incorrect because low HCO3- and high PaCO2 are signs of metabolic acidosis, not alkalosis. Metabolic acidosis is a condition where the blood pH is lower than the normal range of 7.35 to 7.45, due to an excess of acids or a loss of bases in the body. This is incorrect because low PaCO2 and low HCO3- are signs of respiratory acidosis, not alkalosis. Respiratory acidosis is a condition where the blood pH is lower than the normal range of 7.35 to 7.45, due to impaired gas exchange or hypoventilation, which causes carbon dioxide to accumulate in the blood. This is correct because low PaCO2 and high HCO3- are signs of alkalosis. Alkalosis is a condition where the blood pH is higher than the normal range of 7.35 to 7.45, due to a loss of acids or an excess of bases in the body. There are two types of alkalosis: respiratory and metabolic. Respiratory alkalosis is caused by hyperventilation, which lowers the PaCO2 in the blood. Metabolic alkalosis is caused by vomiting, diuretics, or excessive intake of antacids, which raises the HCO3- in the blood. This is incorrect because high PaCO2 and high HCO3- are signs of compensation, not alkalosis. Compensation is a process where the body tries to restore the normal pH by adjusting the levels of PaCO2 and HCO3- in the opposite direction of the primary disorder.

Correct Answer: B

Rationale: Moist skin is not a sign of dehydration, but rather a sign of adequate hydration or sweating. Dehydration can cause dry skin, mucous membranes, and lips. Dark-colored urine is a sign of dehydration, as it indicates a high concentration of waste products and a low volume of water in the urine. Dehydration can cause the kidneys to conserve water and produce less urine. High blood pressure is not a sign of dehydration, but rather a sign of fluid overload or other factors such as stress, pain, or medication. Dehydration can cause low blood pressure, as it reduces the blood volume and the cardiac output. Distended neck veins are not a sign of dehydration, but rather a sign of fluid overload or right-sided heart failure. Dehydration can cause flat neck veins, as it reduces the venous return and the central venous pressure.