Which of the following is a function of the liver? MCQ with Answer and Explanation

Explanation:
The cardiac conduction system ensures coordinated heartbeats. The sinoatrial (SA) node generates the electrical impulse, acting as the natural pacemaker. The impulse reaches the atrioventricular (AV) node, which delays it slightly to allow the atria to fully contract and empty into the ventricles. The impulse then travels down the Bundle of His to the Purkinje fibers, which rapidly distribute it throughout the ventricular myocardium, causing ventricular contraction. All statements are correct.

Explanation:
Fats yield about 9 kcal/g of energy, more than double the 4 kcal/g provided by carbohydrates and proteins. Roughage (dietary fiber) adds bulk to the stool and stimulates peristalsis, preventing constipation. Water is an essential nutrient, crucial for hydration, solvent functions, and temperature regulation, though it provides no calories. Thus, statements 1 and 2 are correct.

Explanation:
Resistin is a cysteine-rich peptide hormone secreted primarily by adipose tissue in humans (though in rodents, it is mainly secreted by macrophages). Its name is derived from its proposed role in 'resistance' to insulin. Its primary function is to antagonize the action of insulin, thereby promoting insulin resistance. It does this by increasing hepatic glucose production (gluconeogenesis) and impairing glucose uptake by muscle and adipose tissue. Elevated levels of resistin are associated with obesity and type 2 diabetes, linking adiposity to insulin resistance.