Final answer:
The large intestine completes absorption of nutrients and water, synthesizes vitamins, forms feces, and eliminates waste from the body. Key regions include the cecum, colon, and rectum, with bacterial flora aiding in digestion and mucosa cells easing feces passage.
Step-by-step explanation:
The large intestine is an essential part of the human digestive system, serving several critical functions. Its primary role is to finish the absorption of nutrients and water, which begins in the small intestine. The large intestine consists of three main regions: the cecum, colon, and rectum. It helps in synthesizing certain vitamins, forms feces from the indigestible material, and is responsible for the ultimate elimination of feces from the body.
In addition, the large intestine houses a rich bacterial flora, which aids in breaking down carbohydrate residues and synthesizing certain vitamins, further contributing to digestion and health. The mucosa of the large intestine contains many goblet cells that secrete mucus to ease the passage of feces. The entry of feces into the rectum triggers the defecation reflex, culminating in the excretion of waste.