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Digestive System Tyra Austria period 6 - Coggle Diagram
Digestive System Tyra Austria period 6
Major functions
Digestion
Absorbs and digests food and eliminates solid waste from the body
Ingested nutrients including proteins, fats, carbohydrates, vitamins, minerals, and water are reduced into molecules small enough to pass through the lining of the gut and so they can enter the bloodstream
Digestion is the breakdown of food into small molecules, which are then absorbed into the body. The digestive system is divided into two major parts: The digestive tract (alimentary canal) is a continuous tube with two openings: the mouth and the anus.
Absorption
The muscles of the small intestine mix food with digestive juices from the pancreas, liver, and intestine, and push the mixture forward for further digestion. The walls of the small intestine absorb water and the digested nutrients into your bloodstream.
The digested nutrients pass from the gut into the blood so the circulatory system or lymph system can pass them on to the rest of the body to use or store
Motility
This refers to the movement of the food from the mouth to the pharynx esophagus, stomach, small and large intestines and out of the body.
Involves the breakdown and mixing of ingested nutrients all the way through the elimination of undigested waste from the body
Secretion
Secretions into the small intestine are controlled by nerves, including the vagus, and hormones. The most effective stimuli for secretion are local mechanical or chemical stimulation of the intestinal mucous membrane. Such stimuli always are present in the intestine in the form of chyme and food particles.
This is the release of enzymes, hormones, and other substances that help the body digest the food that is eaten
Gastric secretions facilitate the digestion of protein which commences in the stomach by acid denaturation and hydrolysis by gastric proteases or pepsins.
Digestive enzymes
Digestive enzymes are released, or secreted, by the organs of the digestive system. These enzymes include proteases that digest proteins, and nucleases that digest nucleic acids. Examples of digestive enzymes are:
Amylase
, produced in the mouth. It helps break down large starch molecules into smaller sugar molecules.
Pepsin
, produced in the stomach. Pepsin helps break down proteins into amino acids.
Trypsin
, produced in the pancreas. Trypsin also breaks down proteins.
Pancreatic
lipase, produced in the pancreas. It is used to break apart fats.
Deoxyribonuclease and ribonuclease,
produced in the pancreas. They are enzymes that break bonds in nucleic acids like DNA and RNA.
Major organs
mouth
After you start eating, you chew your food into pieces that are more easily digested. Your saliva mixes with the food to begin to break it down into a form your body can absorb and use. When you swallow, your tongue passes the food into your throat and into your esophagus.
the
esophagus
receives food from your mouth when you swallow. The epiglottis is a small flap that folds over your windpipe as you swallow to prevent you from choking
Stomach
a hollow organ, or "container," that holds food while it is being mixed with stomach enzymes. These enzymes continue the process of breaking down food into a usable form. When the contents of the stomach are processed enough, they’re released into the small intestine.
The
small intestine
breaks down food from the stomach and absorbs much of the nutrients from the food.
pancreas
makes pancreatic juices called enzymes. These enzymes break down sugars, fats, and starches. Which also help
liver
makes a digestive juice called bile that helps digest fats and some vitamins. Bile ducts carry bile from your liver to your gallbladder for storage, or to the small intestine for use.
The
gallbladder
stores and concentrates bile from the liver, and then releases it into the duodenum in the small intestine to help absorb and digest fats.
Large intesrine:
absorb water and salts from the material that has not been digested as food, and get rid of any waste products left over.
The
rectum's
job is to receive stool from the colon, let you know that there is stool to be evacuated (pooped out) and to hold the stool until evacuation happens.
Anus
: The internal anal sphincter relaxes and pushes the stool from the rectum into the anal canal.
Disorders of the digestive system
Ulcer: The bacteria or NSAIDs can damage the mucus that lines the inside of the stomach, exposing the interior of the stomach to acid which irritates the tissue and causes the peptic ulcer. Essentially a sore on the inside of the stomach, these can be very difficult to resolve because of the constant exposure to stomach acid.
Chronic Diarrhea; Diarrhea is tricky to treat because it can have so many possible causes. It could be a result of the body’s inability to absorb foods — as with celiac disease and foods containing gluten — or a disease or disorder, like irritable bowel syndrome (IBS), Crohn’s disease or ulcerative colitis. Infections — often viral — and even parasites can also be to blame.
Gastroesophageal Reflux Disease (GERD) ; GERD most often presents as heartburn, but uncontrolled GERD can erode the lining of the esophagus and lead to bleeding. The condition can also cause pain in the chest so extreme that it is sometimes mistaken for a heart attack.
Location of digestion and absorption of each macromolecule
Digestive enzymes are enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body. Digestive enzymes are found in the digestive tracts of animals.
The chemical digestion of lipids begins in the mouth. The salivary glands secrete the digestive enzyme lipase, which breaks down short-chain lipids into molecules consisting of two fatty acids. A tiny amount of lipid digestion may take place in the stomach, but most lipid digestion occurs in the small intestine
he small intestine is an organ where most of the digestion and almost all of the absorption takes place. It consists of three parts - the duodenum, the jejunum and the ileum. The duodenum is where the majority of the digestion occurs while the jejunum and ileum is where the absorption takes place
Layers of the GI tract
Muscularis
. The third layer is made of thick muscles. They help to mix food with the digestive juices.
Subserosa
. This layer contains supporting tissues for the serosa.
Mucosa
is the first and innermost layer or lining. It contains the glands that release digestive juices. These are called hydrochloric acid and pepsin. This is where most stomach cancers start.
Serosa
the last and outermost layer. It’s the lining that wraps around the stomach to confine it.
The
submucosa
is the second layer that supports the mucosa. It is rich in blood vessels, lymphatic vessels, and nerves.