Describe the pathway and process of ingestion digestion absorption and transport and assimilation involved when a person has eaten a butterd polony sandwich
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When a person eats a buttered polony sandwich, the pathway and process of ingestion, digestion, absorption, transport, and assimilation are as follows:
1. Ingestion: The process begins when the person takes a bite of the buttered polony sandwich. Ingestion refers to the intake of food through the mouth.
2. Digestion: Once the sandwich is in the mouth, the mechanical and chemical processes of digestion begin. Mechanical digestion involves chewing and breaking down the food into smaller pieces. Enzymes in the saliva, such as amylase, start the chemical digestion by breaking down carbohydrates.
3. Swallowing: After chewing, the partially digested food, known as a bolus, is swallowed. The bolus is moved down the esophagus by peristaltic contractions, a squeezing motion of the muscles in the esophagus.
4. Stomach: The bolus enters the stomach, where the process of digestion continues. The stomach produces gastric juices containing hydrochloric acid and enzymes like pepsin, which break down proteins into smaller peptides.
5. Small Intestine: The partially digested food leaves the stomach and enters the small intestine, specifically the duodenum. In the small intestine, bile produced by the liver and stored in the gallbladder emulsifies fats, and enzymes from the pancreas break down carbohydrates, proteins, and fats further. This is where most of the digestion and absorption take place.
6. Absorption: The nutrients, such as carbohydrates, proteins, fats, vitamins, and minerals, are absorbed through the walls of the small intestine into the bloodstream. Carbohydrates are broken down into glucose, proteins into amino acids, and fats into fatty acids and glycerol. These nutrients are then transported to various organs and tissues in the body through blood vessels.
7. Transport: Once the nutrients are absorbed into the bloodstream, they are transported to the liver, which acts as a processing and storage center for nutrients. The liver releases nutrients into the bloodstream as needed or converts excess nutrients into storage forms, such as glycogen or fat.
8. Assimilation: The absorbed nutrients are utilized by cells throughout the body for energy, growth, and repair. Glucose provides energy, amino acids are used for protein synthesis, and fatty acids and glycerol are used for various cellular functions.
Overall, the pathway involves the ingestion of the sandwich, followed by mechanical and chemical digestion in the mouth, stomach, and small intestine. The nutrients are then absorbed into the bloodstream and transported to different parts of the body for assimilation and utilization by cells.