An explorer has been lost in the desert for two days with very little water. As a result, you would expect to observe

Correct Answer: A

Rationale: Dehydration increases vasopressin to conserve water by concentrating urine.

Correct Answer: C

Rationale: Menstruation itself does not directly increase UTI risk; short urethra, anal proximity, and antibiotic-induced flora disruption are established risk factors.

Correct Answer: D

Rationale: Hypotonic fluids have a lower concentration of solutes compared to the body's cells. When these fluids are administered, they can cause water to move into the cells through osmosis, leading to swelling and potentially causing increased intracranial pressure (ICP). Additionally, hypotonic fluids can cause third spacing, which refers to the movement of fluid from the intravascular space into the interstitial space, leading to edema and decreased circulating blood volume. Lastly, excessive intake of hypotonic fluids can result in water intoxication, as the body's electrolyte balance is disrupted.

Correct Answer: A

Rationale: Insulin is good for K+ regulation because it prevents potassium (K+) from being moved out of the cells. Insulin acts as a signal that tells the cells to take up glucose and potassium from the bloodstream. By keeping K+ inside the cells, insulin helps maintain the balance of electrolytes and ensures the proper functioning of various cellular processes. This is important for overall cell health and prevents imbalances that could lead to complications.

Correct Answer: C

Rationale: Calcitonin is a hormone released by the thyroid gland in response to high levels of calcium (Ca++) in the blood. It helps to regulate calcium levels by inhibiting the release of calcium from the bones and promoting its excretion by the kidneys. Therefore, when the Ca++ levels are high, calcitonin is released to lower the calcium levels and maintain homeostasis.