Describe the role of physical digestion in the small intestine and explain how bile contributes to this process.

Physical digestion in the small intestine involves the mechanical breakdown of food by peristaltic contractions and churning, which increases the surface area of the chyme.
Bile, secreted by the liver and stored in the gallbladder, is released into the duodenum where it emulsifies dietary fats.
Emulsification breaks large fat globules into tiny droplets, greatly increasing their surface area.
The larger surface area allows pancreatic lipase to act more efficiently, hydrolysing triglycerides into fatty acids and glycerol.
Physical digestion does not change the chemical structure of the food molecules; it only alters their size and surface area.