Digestive

Written By: Alana D, Michelle L, Grace B, Emme C, Blake T, and Jacob S

The digestive system‘s main job is to turn meals into body fuel. The digestive system includes mouth,esophagus, stomach, liver, gallbladder, pancreas, small intestine, large intestine, appendix, colon, rectum and anus.

**// Mouth - //**
 The teeth tear up food into tinier pieces while the tongue mixes the food up. The tongue is the part of the mouth that moves food around when one is chewing. The tongue also moves the food past the epiglottis (a small flap that closes over the wind pipe) into the esophagus. Salivary Glands produce saliva containing enzymes. These enzymes (in spit or saliva) are then ejected into the mouth to start digestion or start breaking down food. 



**// Esophagus- //**
No digestion occurs here in the esophagus. Food goes from the mouth to the esophogus, which is a tube that is connected to the mouth. The food travels through the esophogus and into the stomach. Peristalsis is a muscle contaction that pushes food through the esophogus toward the stomach.

//** Stomach- **//
The stomach is at the bottom of the esophogus. The two are attached. The stomach is J-Shaped and lined with lots of muscle. The main jobs of the stomach include holding food, breaking down food to create a food mixture, and then slowly draining the food mixture into the small intestine. In the stomach, enzymes break down food. Pepsin digests proteins, and lipase digests fats. Hydrochloric acid (HCL) dissolves food and kills bacteria. The food is then turned into a mixture c alled Chyme.

//** Small Intestine - **//
Most of the digestive process takes place in the small intestine. The small intestine is a long bendy tube that is located under the stomach. It is about 22 ft long when stretched out and 1 1/2 -2 inches wide. It further liquifies the food mixture so the body can abosrb the nutrients like vitamins and minerals from it. This is also where the nutrients from the food are absorbed by the blood stream. In other words, if a person did not have a small intestine, they would die from starvation. Food is absorbed into blood vessels by the villi. The villi are small, fingerlike projections that line the inside wall of the small intestine. The villi absorb the nutrients and move or transfer them to the bloodstream and the liver.The small intestine is made up of three different parts, the duodenum, the jejunum, and the ileum. -//Duodenum// This is located at the begining of the intestine where the stomach and the small intestine meet. It is C-shaped and roughly 25 centimeters long. The duodenum receives the thick liquid mixture of partly-digested food and acid from the stomach. This acid is quickly turned into nutrients.The duodenum also receives bile from the gallbladder, and other digestive enzymes from the pancreas. The nutrients then enter the duodenum through small ducts or tubes. Other glands produce mucus that coats the digestive mixture to help it pass. The bulk of the digestion of proteins, fats and carbohydrates takes place in the duodenum before the material travels further into the small intestine. //<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">-Jejunum // <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">The jejunum is 1-2 m long, and is coiled mid-section of the small intestine. //<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">-Ileum // <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">The ileum is the final portion or end of the small intestine, which leads into the large intestine. The ileum measures 2-4 m in length. //<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">-Jejunum and Ileum // <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">The inner linings of the jejunum and ileum contain the villi. The presence of the villi on the inside of the small intestine means that the surface area is much larger than if the lining were just a flat surface. This increased surface area improves the small intestin's ability to absorb nutrients. The nutrients both the jejunum and the ileum both absorb include: vitamins, minerals, salts, and water.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt;"> **//Liver-//** <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt;">The Liver produces bile and aids drug detoxification. It also has functions including detoxification, protien synthesis and production of biochemicals necessary for digestion. The liver is also a storage place for red blood cells.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">//** Gallbladder- **//
<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt;">The gallbladder stores and releases some bile. Bile is a fluid that aids digestion and is secreted by the liver and stored in the gallbladder.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">//** Pancreas - **//
<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt;">The pancreas helps in digestion by producing pancreatic juices. It also produces insulin which controls blood sugar levels.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">//** Large Intestine - **//
<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;"> Almost at the end of the of the digestive system, the large intestine would be 5 ft long if it was stretched out, and it is 4 inches in circumference. This organ forms a horseshoe shape around the small intestine. It contains the rest of the food, water, and any other undigested particles the body needs. The large intestine also absorbs the water-maintain homeostasis. The last job of the large intestine is to mix the liquid mixture into a solid. <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">//** Appendix - **//
<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt;">The appendix is a tiny tube inside the large intestine. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px; line-height: 23px;">The appendix is not known to do anything important.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">//** Colon - **//
<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;"> The colon is also inside the large intestine. This is where the body can absorb any last minerals.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">//** Rectum- **//
<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;"> The large intestine pushes the solid waste into the rectum. It is actually at the very end of the large intestine. The solid waste stays here until further action when it leaves the body through the anus.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">//** Anus- **//
<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt;">This is where the solid waste (called stool or poop) comes out. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px; line-height: 23px;">The waste then proceeds to make its way to the sewer.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt;">The smooth muscular contraction peristalsis connects the digestive system to the muscular system. Peristalsis contractions push food through the digestive system. This helps the digestive system perform its function. This system also connects to the circulatory system because of nutrients. The small and large intestines absorb nutrients that then travel in the circulatory system through the blood stream.
 * //<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%; margin: 0in 0in 10pt;">Body System Connections- //**

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">The digestive system is not only very interesting but also extremely helpful and important. This is also a very complex system with many crucial steps for digestion. We hope you learned a lot from this informative and wonderful presentation.

//**<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Resources- **// <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">National Geographic <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Kids Health <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">AMA <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Your Gross and Cool Body

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Thanks Mr. Griffith for the power point. We took a lot from it.