Digestion and Absorption of Macronutrients

The human digestion system is a miraculous thing. How foods are digested and absorbed and used for energy is a very amazing, intricate process. Once you have eaten, the brain and hormones send signals to organs in the digestive system to digest and absorb what has been eaten. After digestion and absorption, nutrients are carried by the blood to the cells of the body. The nutrients are changed into energy within the cell. This process is called metabolism. The digestion system consists of the mouth, throat, esophagus, stomach, small intestine, large intestine, and rectum (Sizer & Whitney, 2017). 

Digestion actually starts in the mouth, specifically with starches. Enzymes in the saliva start breaking down the food so it can be swallowed. Once it gets to the stomach, the stomach starts mixing everything around and around with gastric juice, aka acids and enzymes. This is where protein digestion begins. This is the stomachs main function. By this point, the food is now a substance called chyme. The chyme is passed into the small intestine where most of the digestion of food and absorption of nutrients happens. The pancreas releases a pancreatic juice containing bicarbonate, which helps digest carbohydrates, fat, and protein. Once everything is digested and nutrients are absorbed, it passes into the large intestine where most of the water is removed and we are left with a paste-like substance. Next, well you know what happens, waste leaves the body (Crash Course, 2012). You can watch a very scientific and detailed explanation of the digestive process HERE. 

As you can see, a lot goes into the process of digestion and absorption. It's more than just eating and eliminating waste". The next time you eat, you can think about where the food is going, how it gets through the body and the benefits along the way! ;)

Hugs and Blessings, 

A. Gish

References:

Crash Course. (2012, August 6). The digestive system: Crashcourse biology #28  (Links to an external site.)Links to an external site.[Video file]. Retrieved from http://www.youtube.com/watch?v=s06XzaKqELk

Sizer, F. & Whitney, E. (2017). Nutrition: Concepts and controversies. (14^thed). Retrieved from 

https://content.ashford.edu/books/Sizer.2199.17.1/sections/ch3-sec11