- Slides: 36
The Digestive System
The Digestive System 1 -4 Mouth � 4 -5 Salivary Glands � 6 Liver � 7. Gallbladder � 8. Duodenum � 9. Large Intestine � 10 Anus � 11. Parotid gland � 12. Pharynx � 13. Esophagus � 14. Stomach � 15. Pancreas � 16. Small Intestine � 17. Rectum � 2
Lets get a quick visual of the system and how it works! �https: //www. youtube. com/watch? v=ZB ZWgrf. ZFb. U
Main Functions �Digestion – breakdown of foods within stomach and intestines for use by body’s cells �Absorption – passage of digested food from digestive tract into blood �Elimination – body’s expulsion of undigested food or body wastes.
The Digestive Process � 4 sections ◦ ◦ 1. Mouth 2. Throat 3. Stomach 4. Intestines
The Digestive Process - Mouth �Teeth break food you eat into smaller pieces. �Mastication – the process of chewing. �Saliva is produced by salivary glands. Saliva contains an enzyme that breaks down food in the mouth ◦ Amylase: An enzyme, found in saliva and pancreatic fluid, that converts starch and glycogen into simple sugars) �Tongue – shapes and prepares food for
Enzyme �biological molecules (typically proteins) that significantly speed up the rate of the chemical reactions that take place.
The Digestive Process- Mouth The Mouth (cont. ) 3 4 1. Parotid gland. 2. Submandibular gland. 3. Tongue. 4. Tooth. 5. Sublingual gland. 1 2 5 9
The Digestive Process- Throat � The Pharynx � The Esophagus ◦ Passageway for food and air. ◦ Epiglottis covers the trachea when we swallow. ◦ Uvula prevents food from going to the nasal passages. ◦ 10 inch. muscular tube that connects the throat to the stomach. ◦ Contracts to move food to stomach. ◦ The cardiac sphincter, a group of muscles, closes the entrance to the stomach to prevent backflow of food. 11
Peristalsis �Peristalsis – series of involuntary muscle contractions that move food through the digestive system �(similar to squeezing a tube of toothpaste from the bottom up) �http: //www. youtube. com/watch? v=YJ 3 4 Qx 6 hz. Jk
The Digestive Process - Stomach �Stomach - hollow sac-like organ connected to the esophagus �Functions: - digests food with gastric juices - moves food into small intestine �Converts food into chyme - a creamy mixture of food and gastric juices.
The Digestive Process - Intestines �From the stomach, food moves into small intestines ◦ 20 -23 feet long, has 3 parts: duodenum, jejunum, and illeum. ◦ This is where most of the nutrients from food are absorbed into the body!!! ◦ Receive chyme from the stomach, bile from the liver, and pancreatic juice from pancreas. ◦ Absorption occurs over 1 to 6 hours �Villi – the wall are lined with tiny fingerlike projections that help absorb
The Digestive Process - Intestines �Large Intestine- about 5 ft long and forms a rectangle around small intestine. ◦ Has 4 main parts: cecum, colon, sigmoid colon, and rectum �Any unabsorbed material goes from the small intestine into the large intestine �Here water is absorbed; helps to eliminate waste �Undigested food passes through the large intestine; or the colon and exits through the anus
Helpers of the Digestive System It is important to note food DOES NOT pass through these organs! Liver, Gallbladder, and Pancreas are accessory organs that help AID in digestive activities.
Helpers of the Digestive System Liver �Produces bile �Bile – a green fluid that helps breakdown fats Gallbladder �Small pouch which stores the bile from the liver. It is stored until its needed for digestion. �Once its ready its released into the duodenum, where it aids in the breaking down of fats. Pancreas �produces pancreatic juices that contain enzymes to help breakdown food. �produces insulin to help regulate blood sugar levels.
The Process of Digestion �Mechanical Digestion: Process of physically breaking down food through chewing. �Chemical Digestion: Occurs when food molecules are further broken down with the help of enzymes 22
Digestion �While mechanically breaking down food in the mouth, enzymes in the saliva begin to chemically break the food molecules down into useable nutrients �Once the food has been reduced to a soft mush, the tongue pushes the food to the back of the mouth, causing the swallowing reflex
�Food is pushed to the esophagus, where it slides to the stomach in less than 10 seconds. �Small glands in the stomach produce enzymes and acid which further break down food particles into nutrients �After a few hours (2 -6) of being broken down, the food exits the stomach as a soupy mixture called chyme 24
�After leaving the stomach, chyme is pushed into the small intestine, where the process of absorption will begin. �At this point, fluids produced by the pancreas to protect the small intestine from the acid in the chyme are released �The Small Intestine is the MAIN point of absorption of nutrients into the blood (and eventually the cells). 25
�Numerous small, finger-like projections called villi poke out into the tube of the small intestine, greatly increasing its surface area. �The increase in surface area allows for more absorption to occur here. �While traveling along the digestive tract, bile produced by the liver is secreted into the small intestine through the 26
�Food that cannot be directly absorbed into the blood is pushed from the small intestine into the large intestine. �The large intestine is capable of absorbing most of the water from the food remains, turning them into a semisolid mass known as feces, or stool. �Feces are stored in the rectum until they can be expelled out the anus. 27
Functional Problem: Heartburn Gas Nausea
HEARTBURN �Caused by acid refluxing back into the esophagus. �Foods that increase the production of acid, smoking, pregnancy, obesity, and
GAS �Gas collects in two main ways. Swallowing air while you eat or drink can cause oxygen and nitrogen to collect in the digestive tract. �As you digest food, the bacteria in your tract mixed with food can produce digestive gases such as hydrogen sulfide gas.
NAUSEA �Any problems during this digestive process can cause nausea after eating. �Symptoms will often develop in the stomach or upper abdominal area, where the large-scale breakdown of food begins. �Sometimes the body reacts to these problems by forcibly emptying the stomach, usually through vomiting. �Hormonal changes, infection, food intolerance, or gastrointestinal problems.
GASTRITIS � an inflammation, irritation, or erosion of the lining of the stomach. It can occur suddenly (acute) or gradually (chronic). � caused by infection, irritation due to excessive alcohol use, chronic vomiting, stress, or the use of certain medications such as aspirin or other antiinflammatory drugs. � Treatment: antacids medication to reduce stomach acid, avoiding hot, spicy, or irritating foods
Lactose Intolerance �A deficiency of lactase — an enzyme produced in your small intestine — is usually responsible for lactose intolerance. �Many people have low levels of lactase but are able to digest milk products without problems. If you're actually lactose intolerant, though, your lactase deficiency leads to symptoms after you eat dairy foods
Peptic Ulcers �Open sores that develop on the inside lining of your stomach and the upper portion of your small intestine. The most common symptom of a peptic ulcer is stomach pain. �The most common causes of peptic ulcers are infection with a certain bacteria and long-term use of aspirin and certain other painkillers.
HEMORRHOIDS �Swollen and inflamed veins in the rectum and anus that cause discomfort and bleeding. �Hemorrhoids are usually caused from straining during bowel movements, obesity, or pregnancy. �Discomfort is a common symptom, especially during bowel movements or when sitting. Other symptoms include itching and bleeding. �A high-fiber diet can be effective, along with over-the-counter medications.
Digestive System Care �Eat foods high in fiber ◦ Fiber helps food and waste pass through the digestive tract ◦ Reduces risk of colon cancer ◦ Beans, Prunes, Pears, and Leafy Green Vegetables are good sources �Drink plenty of water ◦ 8 glasses a day! ◦ Helps keep things moving regularly �Eat slowly and don’t hurry through your meals ◦ Eating too fast can cause gas or indigestion