Chapter 3 Flashcards
connection between atoms, elements, cells, tissues, and organs; the organ systems in the body
Atoms combine to form elements element create cells, cells group into tissues, and tissues make up organs which function in organ systems, creating organism
Gastrointestinal Tract
consists of the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus
Digestive Secretions
Consist of Enzymes and Hormones
Enzymes
Speed up digestion
salivary amylase
in the mouth breaks down carbohydrates (Large starch to smaller)
Renin
In the stomach, causes milk protein casein to curdle
Pepsin
In the stomach, breaks proteins into polypeptides and amino acids
Trypsin
In the Pancreas, Breaks proteins and polypeptides into shorter polypeptides
Chymotrypsin
In the small intestine, Breaks proteins and polypeptides into shorter polypeptides
Carboxypeptidase,
aminopeptidase, and dipeptidase
In the small intestine, Break polypeptides into amino acids
Pancreatic Lipase
Breaks triglycerides into monoglycerides, fatty acids, and glycerol
Pancreatic amylase
Breaks starch into shorter glucose chains and maltose
Lipase
Breaks monoglycerides into fatty acids and glycerol
Sucrase
Breaks sucrose into glucose and fructose
Maltase
Breaks maltose into glucose
Dexitinase
Breaks short chains of glucose into individual glucose molecules
Hormones
Secretin and cholecystokinin regulate secretions in the small intestine
Gastrin
In the stomach Mucosa, secretion of HCL and pepsinogen by gastric glands and increases gastric mobility and emptying
(movement of food through stomach)
Somatostatin
In stomach and duodenal mucosa, inhibits stomach secretion, mobility, and emptying; pancreatic secretion, absorption, gallbladder contraction, and bile release
Secretin
in Duodenal Mucosa, stimulates the pancreas to release bicarbonate-rich fluids, which neutralize stomach acid in the small intestine, and regulates the secretion of digestive enzymes
Cholecystokinin (CCK)
Stimulates contraction of gallbladder to expel bile; increases output of enzyme-rich pancreatic juice
Gastric inhibitory peptide
Inhibits gastric secretion and motility
GI Tracts Role in Immune Function
The GI tract limits the
absorption of toxins
and disease-causing
organisms.
Regulation of GI tract
Involve hormones and neural signals that control digestion.
Carbohydrates
Begin digesting in the mouth (salivary amylase), continue in the small intestine (pancreatic amylase).
Proteins
Start in the stomach (pepsin), continue in the small intestine (proteases from pancreas).
Fats
Digestion begins in the small intestine, aided by bile from the liver and lipase from the pancreas.
Peristalsis
Rhythmic contractions moving food through the GI tract.
Epiglottis
Flap preventing food from entering the windpipe.
Parietal Cells
Cells in the stomach that produce hydrochloric acid.
Intrinsic Factor
A protein necessary for vitamin B12 absorption.
Pepsin
An enzyme in the stomach that breaks down proteins
Immune Role of the GI Tract
helps protect the body from toxins and pathogens by limiting their absorption. Immune cells like phagocytes and lymphocytes are present in the GI tract
Ancillary organs
Liver, Gallbladder, Pancreas, Large intestine
Liver
Produces bile to emulsify fats
Gallbladder
Stores bile and releases it into the small intestine.
Pancreas
Produces digestive enzymes and bicarbonate.
Large Intestine
Absorbs water and forms waste
Common Digestive Problems
Heartburn, Reflux, Ulcers, Constipation, and Diarrhea
Heartburn/Reflux
Stomach acid entering the esophagus. (overeating, anxiety, stress, pregnancy, hiatal hernia, or diesease processes
Ulcers
Erosion in the stomach lining. Pain, bleeding, infection abdominally
Constipation
Difficulty in bowel movements.
Diarrhea
Frequent loose or watery stools
