ACTIVITY 1
1. How the food changes consistency and form
Food enters the digestive tract when we eat. The digestive system is made up of a number of organs that connect the mouth to the anus. This route results in the processing and waste conversion of food. Food is expelled from the body via bowel movements after it has been converted to waste. The following bullets outline how food is broken down by the digestive tract:
- Firstly, the mouth, where food is masticated or chewed, is where the physical and chemical digestion processes get started. The mouth mechanically cuts the large pieces of food into smaller bits, then blends them with saliva to create a semi-solid paste called bolus. The mouth is also where hydrolysis and swallowing take place.
- As the bolus travels down the esophagus, it reaches the stomach, where the churning process physically shears the bolus to even smaller particles. Bolus is chemically synthesized by the stomach's acid and enzymes, which break down complex compounds into their more basic forms. These procedures change the bolus into the chyme, a more fluid-like state.
- After that, chyme travels to the small intestine, where hydrolysis occurs, nutrients are absorbed, and liquid waste is left.
- Other substances like ions and vitamin K are absorbed in the colon or large intestine. It also takes the water out of liquid waste, turning it into solid waste or stool.
- The rectum then stores the feces until a bowel movement takes place, at which point the anus helps in stool expulsion.
2. How the body was able to absorb the nutrients from the foods we eat.
The series of physical and chemical processes that take place along the gastrointestinal or digestive tract enable the body to absorb the nutrients from the meals we eat. These processes cause the food's form and consistency to change, which aids in breaking it down into smaller units for easier passage through the GI tract and eventual absorption of released nutrients in the intestines.
Specifically, segmentation and hydrolysis take place when chyme enters the small intestines so that nutrients will be released in the form of less complex substances such as glucose, fatty acids, glycerols, amino acids, and nucleic acids. The large intestines are where other nutrients including water, ions, and vitamin K are absorbed.
References:
Betts, J. G., Wise, J., Young, K. A., Desaix, P., Johnson, E., Johnson, J. E., Korol, O., Kruse, D., Poe, B., Womble, M. D., & Openstax College. (2017). Anatomy and physiology. Xanedu ; Houston, Texas. https://openstax.org/details/books/anatomy-and-physiology (Original work published 2013)
Saint Luke's. (2022). How Food Moves Through Your Body. Saint Luke’s Health System. https://www.saintlukeskc.org/health-library/how-food-moves-through-your-body
Tortora, G. J., & Derrickson, B. (2014). Principles of Anatomy and Physiology (14th ed.). Wiley.