per-cutaneous endoscopic gastrostomy, (PEG tube) inserted below duodenum

digestive system

essential nutrients needed by the human body and how they are digested

accessory digestive organs include:

GI tract includes :

oral cavity (home of the teeth and tongue) where physical breakdown of food occurs, and chemical breakdown is initiated)

pharynx is a passageway for both food bolus' and air. its main function is to provide passage to the stomach via several phases including swallowing (voluntary) and peristalsis (involuntary)

esophagus

stomach

small intestine

large intestine

anal canal (including the rectum) is a muscular tube that stores fecal material prior to defecation

teeth (perform mechanical breakdown of food)

tongue

salivary glands (moistens ingested food, and initiates the chemical breakdown)

liver (produces bile which, is an alkaline fluid that functions in the mechanical digestion of lipids)

gallbladder ( stores, concentrates, and releases bile that is produced by the liver)

pancreas ( produce and secrete the hormones insulin and glucagon; and produce pancreatic juice) the pancreas also acts as an alkaline buffer to counter the acids used to breakdown food

initiates chemical breakdown of fats and proteins

stomach lining is made of gastric folds, and smaller gastric pits used to increase surface area for food breakdown via secreted enzymes and acids

body is the largest section, and expands to store more food

pyloric sphincter controls entry of chyme to the duodenum (first section of small intestine)

small intestine includes the duodenum, jejunum, and ileum.

chyme enters the small intestine for further chemical breakdown and almost all nutrients are absorbed here

chyme moves through the small intestine via peristalsis

small intestines are lined with villi, lacteal, micro-villi, intestinal glands, submucosal glands, goblet cells, and brush border enzymes. all to aid in chemical breakdown and absorption of nutrients

large intestine made of 3 section. the cecum, the colon, and the rectum

water and electrolytes are absorbed here, and the remaining digested material is compacted into feces

the second section of the large intestine is the colon, which is made of the ascending colon, transverse colon, descending colon and sigmoid colon regions

carbohydrates

lipids

proteins

minerals

vitamins

water

1) salivary amylase begins the breakdown of starch in the oral cavity 2) pancreatic amylase continues starch digestion 3) Dextrinase and glucoamylase break down bonds between glucose molecules 4) maltase, lactase, sucrase breakdown maltose, lactose, and sucrose respectively. these are all brush border enzymes that line the small intestine

30% of triglycerides are digested by lingual and gastric lipase which is activated in the stomach. pancreatic lipase digests the rest in the small intestine.

proteins are broken down into amino acids. pepsin denatures proteins in the stomach. enteropeptidase activates trypsin, chymotrypsin, and
carboxypeptidase in the small intestine.Trypsin and chymotrypsin break peptide bonds to produce smaller strands of amino acids and Carboxypeptidase removes amino acids from the carboxyl end of a protein. this is performed in the small intestine. dipeptidase breaks down the bonds of dipeptides. aminopeptidase generates free amino acids from amino peptides. these fuctions are also performed in the small intestine.

nucleic acids are broken down by deoxyribonuclease, ribonuclease, phosphatase, and nucleosidase. this all occurs in the small intestine.

feeding tube used to bypass the oral cavity, pharynx,salivary glands, esophagus, stomach and duodenum

cholecystectomy

bile produced by the liver will no longer be secreted into the small intestine via the bile duct

food will no longer be able to be mechanically broken down, and the chemical breakdown of food will no longer be initiated by the oral saliva

by skipping the stomach, enzymes and chemicals that usually aid in digestion will no longer be effective. this includes alkaline mucus, gastrin, and hydrochloric acid

the duodenum contains brush border enzymes, intestinal glands, goblet cells, and duodenal glands (submucosal) that may need supplementation

nutrients to be given to our elderly male pt. no longer receive

mechanical breakdown

bile, and pacreatic juice

gastric enzymes and chemicals from the stomach, and duodenum

the food he receives from the PEG tube will need to broken down and also supplemented with the essential vitamin, minerals, carbohydrates, sugars, starches, and proteins that he would receive from a regular healthy diet

salivary enzymes