Question

The functional unit for absorption of digested food is
A. Crypts of Lieberkuhn
B. Peyer’s Patches
C. Villi
D. Brunner’s Gland

Answer 1

Digestion is a metabolic reaction wherein food breaks down into nutrients. Nutrients such as carbohydrates, proteins, fats, and vitamins are derived from food sources. Carbohydrates include starch, sugar, fiber, etc. Proteins are derived from foods such as eggs, meat, beans, etc.

Complete answer: The digestive system of humans includes the gastrointestinal tract and other solid organs such as the pancreas, gallbladder, and liver that facilitate in the digestion process. The gastrointestinal tract constitutes the mouth, oesophagus, stomach, small intestine, large intestine, and anus. In the first stage of the digestion process, gastric secretions are released in response to the smell and sight of food, this is called the cephalic phase. This stage involves the breakdown of food by chewing. Digestive enzymes present in the mouth then chemically breakdown the food furthermore. Once the food reaches the inside of the body, different digestive enzymes are released that facilitate the absorption and assimilation of nutrients. Absorption of nutrients is carried out by the ileum and jejunum present lower in the intestine.
-Crypts of Lieberkuhn: The villi epithelium extends down and forms crypts in the lamina propria. These are known as the crypts of Lieberkuhn. The base of the villi of the small intestine is the Crypts of Lieberkuhn. The cells present here are called paneth cells. These cells function to release antibacterial lysozyme.
-Peyer’s Patch: They are also called aggregated lymphatic nodules. These are present throughout the ileum region. They are lymphatic tissues. They monitor the bacterial population and prevent the pathogenic bacterial growth in the intestine. Hence, part-taking in the maintenance of the body’s immune system.
-Villi: Nutrients are absorbed in the small intestine. The walls lining the small intestine have Villi and microvilli that help in nutrient absorption into the lacteals of the lymphatic system and the capillaries of the circulatory system by increasing the surface area.
-Brunner's glands: These are also known as duodenal glands. They are complex tubular submucosal glands present in the duodenum just above the sphincter of Oddi. These glands secrete alkaline mucus that protects and lubricates the intestinal walls. Thus enabling absorption of nutrients in the intestine.
Hence, the correct answer is Option C

Note: Large intestine is known as the largest part of the gastrointestinal tract. Water absorption and waste storage prior to excretion are done here. Defecation is known as the removal of waste from the body.