Draw a labelled diagram of the human digestive system. With the help of this diagram, describe the process of digestion of food in humans.

(N/A) Digestion of food in humans:
$1$. Mouth: Digestion begins in the mouth. Teeth break food into smaller pieces (physical digestion), and salivary glands secrete saliva containing salivary amylase, which converts starch into maltose (chemical digestion).
$2$. Oesophagus: Food moves through the oesophagus to the stomach via rhythmic contractions called peristaltic movements.
$3$. Stomach: Gastric glands secrete gastric juice containing $HCl$, pepsin, and mucus. $HCl$ creates an acidic medium for pepsin to digest proteins into peptones, while mucus protects the stomach lining.
$4$. Small Intestine: This is the site of complete digestion. It receives bile from the liver (which emulsifies fats) and pancreatic juice from the pancreas (containing trypsin for proteins, lipase for fats, and amylase for starch). The intestinal walls secrete succus entericus, which completes the digestion of carbohydrates, proteins, and fats.