Describe, in 200 to 300 words, the path food follows through the digestive system and how digestion occurs in each of the following parts of the digestive system. Be sure to include descriptions of other organs or components of the digestive system, including: Large intestine,Mouth, Small intestine, and Stomach.
This site will help you with this description.
http://kidshealth.org/kid/htbw/digestive_system.html
The digestive system is a complex and fascinating system responsible for breaking down food into nutrients that can be absorbed by the body. Let's take a detailed look at the path food follows and the process of digestion in the major parts of the digestive system: the mouth, stomach, small intestine, and large intestine.
The journey of food begins in the mouth. Here, the food is ingested and subjected to mechanical digestion through the process of chewing and mixing with saliva. Saliva contains enzymes, such as amylase, that begin the process of chemical digestion by breaking down carbohydrates. After being chewed and mixed with saliva, the food forms a soft mass called a bolus, which is then swallowed and transported down the esophagus.
Next, the bolus enters the stomach, where it undergoes further mechanical and chemical digestion. The stomach is a muscular organ that churns and mixes the food with gastric juices, including hydrochloric acid and enzymes like pepsin. The acidic environment in the stomach helps break down proteins into smaller peptides. The stomach also serves as a temporary storage site for food, gradually releasing it into the small intestine.
The small intestine is where the majority of digestion and absorption of nutrients occur. The food enters from the stomach into the duodenum, the first part of the small intestine. Here, the pancreas releases digestive enzymes, including amylase, lipase, and proteases, to break down carbohydrates, fats, and proteins, respectively. The liver also contributes by producing bile, which aids in the digestion of fats. The walls of the small intestine contain tiny finger-like projections called villi, which greatly increase the surface area for absorption of nutrients into the bloodstream.
After passing through the small intestine, the remaining undigested food enters the large intestine, also known as the colon. The main function of the large intestine is to absorb water and electrolytes. The colon is inhabited by beneficial bacteria that help ferment indigestible carbohydrates and produce certain vitamins like vitamin K. The waste material then forms feces, which are stored in the rectum until elimination through the anus.
In summary, food follows a carefully orchestrated path through the digestive system, starting from the mouth and ending in the large intestine. Each stage of the digestive process involves both mechanical and chemical digestion, with the involvement of various organs and enzymes. Working together, these components ensure the effective breakdown and absorption of nutrients from the food we consume.