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:
o Large intestine
o Mouth
o Small intestine
o Stomach
These sites will help you with your description of the digestive system.
http://biology.about.com/library/organs/bldigestoverview2.htm
http://kidshealth.org/kid/htbw/digestive_system.html
(Broken Link Removed)
http://www.enchantedlearning.com/subjects/anatomy/digestive/
The digestive system is responsible for breaking down food into nutrients that can be absorbed and used by the body. It consists of several organs and components that work together to carry out this process. Let's take a closer look at the path food follows through the digestive system and how digestion occurs in each of the mentioned parts.
The journey begins in the mouth, where food is mechanically broken down by chewing and mixed with saliva. Saliva contains enzymes that start the process of chemical digestion by breaking down carbohydrates. Once the food has been thoroughly chewed and mixed with saliva, it forms a bolus and is then swallowed.
From the mouth, the bolus travels down the esophagus, a muscular tube that connects the mouth to the stomach. The esophagus uses rhythmic contractions (peristalsis) to push the bolus downward, eventually reaching the stomach.
In the stomach, food is mixed with gastric acid and digestive enzymes, including pepsin, which begins the breakdown of proteins. The stomach's muscular walls contract to churn and mix the food, turning it into a soupy mixture called chyme. This process also helps to sterilize and partially digest the food. The stomach lining also secretes mucus to protect itself from the strong digestive acids.
Next, the chyme enters the small intestine, a long and coiled tube where most of the digestion and absorption of nutrients takes place. The small intestine is divided into three parts: the duodenum, jejunum, and ileum. The walls of the small intestine are lined with tiny finger-like projections called villi, which greatly increase the surface area for nutrient absorption. The small intestine receives bile from the liver and pancreatic enzymes, which further break down carbohydrates, proteins, and fats. The nutrients are then absorbed through the villi, into the bloodstream, and transported to the rest of the body.
After passing through the small intestine, the remaining undigested material enters the large intestine, also known as the colon. The main function of the large intestine is to absorb water and electrolytes from the undigested food, forming solid waste products known as feces. The large intestine also houses trillions of beneficial bacteria that aid in the digestion of certain substances, such as fiber.
Finally, the feces move into the rectum, where they are stored until they are eliminated through the anus during defecation.
In summary, the path food follows through the digestive system involves the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. Each part has a specific function in the process of digestion, including mechanical and chemical breakdown of food, absorption of nutrients, and elimination of waste.