1. How the food changes consistency and form
There are four steps in the food’s journey through the digestive system. First, we have the process called mastication, otherwise known as chewing, where the food is mechanically sheared into smaller pieces. During mastication, the food mixes with saliva and turns into a semi-solid paste called a bolus, which is something easier to swallow. The tongue and soft palate push the food into the pharynx where swallowing takes place. In the next step, it moves down the esophagus and stomach through a series of muscle contractions called peristalsis, where a churning action continues to make the bolus even smaller in particle size. After which, the it is turned into a more fluid-like form called chyme with the help of the stomach’s secretion of different acids and powerful enzymes. After this step, the chyme travels to the small intestine where physical digestion happens through segmentation. Particularly, the small intestine breaks down and absorbs nutrients from food using enzymes from the pancreas and bile from the liver. Finally, the small molecules are released from food and are rendered free for absorption in the small intestine, and the remains are turned into feces to be eliminated through the rectum and anus.
2. How the body was able to absorb the nutrients from the foods we eat.
The small intestine is where most of the long process of digestion takes place since it systematically breaks down food, absorbs nutrients, extracts water, and moves food along the gastrointestinal tract. However, the second function mentioned is one of its most significant ones, where it absorbs water and digested nutrients into the bloodstream. Finger-like projections, called villi absorb most of the nutrients, particularly carbohydrates, fats, minerals, proteins, and vitamins. The walls of the small intestine are likewise lined with a dense mucosa with many folds, which makes its surface area 100 times as broad as that of the skin, resulting in the absorption of 95% of the carbohydrates and protein as well as 90% of water digested. Meanwhile, the lowest part of the small intestine, the ileum, is where the final parts of digestive absorption take place. it absorbs bile acids, fluid, and vitamin B-12.
REFERENCES:
Bartelby. (n.d.). The Digestive System. Retrieved from https://www.bartleby.com/solution-answer/chapter-23-problem-1ilq-anatomy-and-physiology-1st-edition/9781938168130/by-clicking-on-this-link-httpopenstaxcollegeorglfooddigestion-you-can-watch-a-short-video/cad5bd3e-0e4c-11e9-9bb5-0ece094302b6
University Hospitals. (n.d.). The Digestive Process: What Does the Small Intestine Do? Retrieved from https://www.uhhospitals.org/health-information/health-and-wellness-library/article/adult-diseases-and-conditions-v1/the-digestive-process-what-does-the-small-intestine-do#:~:text=The%20jejunum%20absorbs%20most%20of,%2C%20and%20vitamin%20B%2D12
WebMD. (2022). The Digestive System. Retrieved from https://www.webmd.com/digestive-disorders/digestive-system