Final answer:
The absorption of sodium, chloride, and potassium from the diet is regulated according to the body's needs. These ions are absorbed via active transport and regulated by hormones such as aldosterone and angiotensin II, ensuring the maintenance of a proper electrolyte balance in body fluids.
Step-by-step explanation:
The intestinal absorption of sodium, chloride, and potassium from the diet is regulated according to the body's needs. Sodium and potassium electrolytes are critical for maintaining a narrow range of concentrations in body fluids. Electrolytes such as sodium, potassium, and chloride are absorbed actively throughout the small intestine and their concentrations in body fluids are very closely regulated.
For instance, sodium ions are accumulated inside cells through co-transport mechanisms, while antiport mechanisms reduce the potassium ion concentration inside cells. The sodium-potassium pump, which requires ATP, works to maintain the necessary gradients across the cell membrane by pumping sodium out and potassium in. Additionally, hormones such as aldosterone and angiotensin II principally regulate the exchange of sodium for potassium in the renal collecting tubule.
Chloride, closely associated with sodium, is important in maintaining acid-base balance and is also regulated in tandem with sodium. Hence, the statement 'Absorption is regulated according to body needs' in the question is the correct one.