Non-Ruminants+-+Racoons

=Non-Ruminants - Racoons=

Pre-Small Intestine (Group 3 - Sarah L)
First, a raccoon obtains its food by the process of prehension, usually by using its hands or mouth. Then the process of mastication takes place, and the physical breakdown of food occurs. Raccoons are omnivores, so their teeth are designed to eat both meat and plants. Their front teeth help them rip into meat and bite into fruits and vegetables, and their molars help them grind up meat and chew fruits and vegetables. When the process of mastication is occurring, the submandibular, parotid, and sublingual glands release water, mucin (which acts as a lubricant for the mouth), Sodium Bicarbonate (which acts as a buffer), and salivary amylase (which begins the digestion of starch). Then deglutination (swallowing) occurs and the bolus moves down the esophagus by involuntary peristalsis. Once the bolus travels through the esophagus, it enters the raccoon’s stomach, where the first major digestion of feed occurs. Some major parts of the stomach are the cardiac sphincter, cardiac region, fundic region, pyloric region, and pyloric sphincter. The cardiac and pyloric regions of the stomach secrete mucous. The fundic region is the largest part of the raccoon’s stomach, and this is where the peptic and chief cells are. Food mixes in the raccoon’s stomach, and enzymes and Hydrochloric acid aid in chemical digestion. The Peptic cells in the inactive enzyme pepsinogen, and once the Hydrochloric acid (secreted by the chief cells) and protein is added, pepsinogen is activated into the enzyme pepsin. After the food has traveled through the stomach, it leaves the stomach by travelling through the pyloric sphincter into the duodenum of the small intestine.

Small Intestine (Group 3 -Ashley G)
The small intestine is the site of extreme absorption. The epithelium throughout the small intestine contains enterocytes located on villi, which add extra surface area, allowing for more absorption. To add to this, there are even microvilli on the enterocytes themselves. These are called a brush border. Connective tissues of the small intestine allow for absorption through the passage of blood, nerves and lacteals. The smooth muscle layer surrounding the small intestine facilitates peristalsis, moving the bolus through the small intestine for further reabsorption and eventually passage to the cecum. Around it all lies an external layer of connective tissue for support and protection. The first part of the small intestin in the raccoon is the duodenum. This is an active site of digestion. Pancreatic secretions from the pancreatic duct intermingles with the food bolus here. These pancreatic secretions include multiple zymogens, or inactive enzymes that are necessary for breakdown of protiens and absorption. Of these includes: Trypsinogen, Chymotrypsinogen, Proelastase, and Procarboxy peptidase A & B. These zymogens are all activated by different signal chemicals. Trypsin, one of the more important, signals all these zymogens except Trypsinogen, which is activated by Enterokinase. Other enzymes secreted by the pancrease and made by enterocytes include pancreatic lipase and pancreatic amylase. Amylase is the main enzyme necessary for starch digestion. It breaks starches down into two sugar units. Enterocytes also make the active enzymes maltase, sucrase and lactase, which difest maltose, sucrose and lactose. Another digestion aid added to the mix is bile, which is made in the liver and either sent to the gall bladder where it is stored, or sent straight to the duodenum through the bile duct. Bile is made up of bile salts, bile pigment, mucous and cholesterol. Bile salts emulsify, or break down lipids and phospholipids. Micelles are also created in the duodenum, which helps to transport lipids through the aqueous small intestine. Cholesytokinin is a hormone that is stimulated by fat and protein entering the duodenum. This CCK is also the stimulus which signals the pancreas and gall bladder to contract and squeeze bile and pancreatic juices into the duodenum. The food is absorbed as much as possible in it's time in this area, and peristalsis moves it on to the next part of the small intestine- the jejunum. The jejunum is where the most nutrient absorption takes place. It is the longest section of the small intestine, and has the most surface area and villi. Here, three mechanisms of absorption are used: diffusion, facilitated diffusion and active transport. The last part of the small intestine is the ileum. Little nutrient absorption takes place here before peristalsis moves the bolus on to the cecum, or junction place between the small and large intestine.

Large Intestine (Group 3 - Candace H)
In raccoons the large intestine consists of the cecum, colon, and rectum. The cecum in this species is smalland it and the colon the same functions being that they both have microbeal digestion of fiberous carbohydrates into VFA's, B and K vitamins whitch are then absorbed through the cecal wall. Goblet cells in the colon secrete mucous to help lubricate materials as they pass though here slower. Excess water is absorbed and feces are concentated before moving into the rectum. In the rectum the feces are formed and held before excretion through the anus.

Post Large Intestine (Group 3 - Teal K)
The post large intestine is after the feces are formed by the recum they leave the large intestine making their way to the anus. Once the feces are ready to be excreted The anus is the last part of the alimentary tract where feces are controlled and disposed.