Absorption | Biology for GCSE/IGCSE - Year 11 PDF Download

Absorbing Nutrients

• Absorption involves the transfer of digested food molecules from the digestive system into the bloodstream (glucose and amino acids) and lymphatic system (fatty acids and glycerol). Nutrients are primarily absorbed in the small intestine. 
• Absorption refers to the process where nutrients derived from digested food move from the digestive tract into the blood and lymphatic system. For instance, glucose and amino acids are absorbed into the bloodstream, while fatty acids and glycerol enter the lymphatic system for further transport and utilization in the body.
• The small intestine is the key site for nutrient absorption.
• The small intestine, particularly the duodenum, jejunum, and ileum, plays a crucial role in absorbing nutrients. This is because of its large surface area, aided by villi and microvilli, which facilitate efficient absorption of nutrients into the bloodstream.

Absorbing Water

• Water is absorbed in both the small intestine and the colon, but the majority of water absorption (approximately 80%) occurs in the small intestine.
• Water:  The liquid essential for various bodily functions. 
• Small Intestine:  A crucial part of the digestive system where most nutrient absorption occurs. 
• Colon:  Also known as the large intestine, where water and salts are absorbed before excretion. 
• Most Absorption of Water:  Refers to the fact that the highest percentage of water absorption happens in the small intestine.