Question

Name a common nutrient that is absorbed in the small intestine and reabsorbed by the kidney tubules.

Answer 1

Hint: This nutrient is the most simple type of carbohydrates which is a simple sugar molecule that initiates metabolism and can be converted easily for energy. It easily enters the bloodstream and is used for energy.

Complete answer:
The common nutrient that is absorbed in the small intestine and reabsorbed by the kidney tubules is the ‘Glucose’. Glucose is the simplest form of sugar and the most fundamental unit of carbohydrates derived by the digestion of complex carbohydrates in the small intestine. It is one of the most important and vital sources of energy. Therefore, it is absorbed into the walls of the small intestine by the adjoining blood capillaries so that it can be transferred or carried on by the stream of blood to distinct parts of the body.
When the blood reaches the kidney, it gets filtered and the process of urine formation occurs. During this process, substances like glucose are reabsorbed by the kidney tubules so that such vital substances are not released out by the body through urine.

Additional information:
Absorption:
- Absorption is the process by virtue of which the end products of digestion proceed into the blood or lymph through the intestinal mucosa.
- Absorption of substances occurs in different parts of the alimentary canal like the mouth, stomach, small intestine, and large intestine. However, maximum absorption takes place in the small intestine.
Tubular reabsorption:
- A correlation of the volume of the filtrate made per day (180 liters per day) with that of urine discharged (1.5 liters), indicates that about 99% of the filtrate has to be reabsorbed by the kidney tubules. This process is known as reabsorption.
- Substances like glucose in the filtrate are reabsorbed actively while the nitrogenous wastes are absorbed by passive transport.

Note:
- Some substances like fructose and some amino acids are absorbed with the help of the carrier ions like sodium ions. This process of absorption is called facilitated transport.
- finger- like projections are present in the small intestine, this structure is known as villi. Villi increases the surface area of the secreting and absorbing surface.