DIGESTIVE CONNECT
Duodenum
Bile; Chymotrypsinogen; Pancreatic Lipase; Ribonuclease; Deoxyribnuclease.
Dipeptidase
Breaks apart the final two amino acids resulting from a former protein.
Glucoamylase
Brush-border enzyme that breaks down ogliosaccharides.
Lactase
Brush-border enzyme that is vital to the digestion of breast milk.
Maltase
Brush-border enzyme that targets the release of glucose from maltose.
Digestive Tract
Buccal Cavity; Duodenum; Jejunum; Ileum; Colon; Rectum.
Regenerative Cells
Divide rapidly and provide a continuous supply of new cells.
Deoxyribonuclease
Enzyme that breaks down DNA.
Ribonuclease
Enzyme that breaks down RNA.
Pancreatic Lipase
Enzyme that produces two free fatty acids and a monoglyceride.
Salivary Amylase
Hydrolyzes starch, but is deactivated in the stomach.
Small Intestine
Jejunum; Ileum; Duodenum.
Mechanical Digestion
Mastication; Segmentation; Churning; Peristalsis; Haustral Contractions; Bolus Formation.
Lingual Lipase
Mouth-secreted enzyme that increases in activity upon contacting the HCI of the stomach.
DIGESTIVE PROCESS: DEFECATION
5. The final step requires defection, where the fecal matter resulting from compaction is excreted from the body.
PROXIMAL TO DISTAL THROUGH DIGESTIVE TRACT: ILEOCECAL
5. The junction of small and large intestines is marked by a pronounced musclar swelling known at the ileocecal sphincter, which regulates movement into the large intestine.
PROXIMAL TO DISTAL THROUGH DIGESTIVE TRACT: INTERNAL ANAL
6. The involuntarily controlled internal anal sphincter is composed of smooth muscle that relaxes at the onset of defecation.
PROXIMAL TO DISTAL THROUGH DIGESTIVE TRACT: EXTERNAL ANAL
7. The final step in allowing defecation is voluntary relaxation of the external anal sphincter, which is composed of skeletal muscle.
HCI
Acid compound that activates pepsinogen.
Pepsin
Acidophilic enzyme that cleaves all peptide bonds between tyrosine and phenylalanine.
Acid
5. Small peptides buffer stomach acid so the pH does not fall excessively low.
Proteins
5. The build up of pepsin will then digest proteins.
Myenteric
1. During the gastric phase, food stretches the stomach and activates myenteric and vagovagal reflexes.
Chief Cells
1. In the gastric gland, the chief cells secrete pepsinogen.
PROTEIN DIGESTION AND ABSORPTION: MECHANICAL
1. The act of protein digestion begins in the mouth with mechanical digestion.
DIGESTIVE PROCESS: INGESTION
1. The digestive process begins with the ingestion of foods.
STARCH DIGESTION FROM BEGINNING TO END: MOUTH
1. The entire process of starch digestion begins in the mouth with amylase.
PROXIMAL TO DISTAL THROUGH DIGESTIVE TRACT: OBICULARIS ORIS
1. The first sphincter of the digestive system, called the obicularis oris mucle, surrounds the entrance to the oral cavity.
Hepatic Triad
1. Three main vessels make up the hepatic triad. These include the hepatic portal vein, hepatic artery and bile ductules.
ACTIVATION OF PANCREATIC ENZYMES: PANCREAS
1. When stimulated, the pancreas will secrete trypsinogen.
HCI
2. Also in the gastric gland, the parietal cells will secrete HCI.
Poor
2. Blood arrives at the liver through both the hepatic portal vein and the hepatic artery, although the hepatic portal vein delivers nutrient rich, oxygen poor blood to the liver cells.
PROTEIN DIGESTION AND ABSORPTION: PEPSIN
2. Once in the stomach, pepsin hydrolyzes peptide bonds.
STARCH DIGESTION FROM BEGINNING TO END: OLIGOSACCHARIDES
2. Starch is digested first into ogliosaccharides, then into disaccharides.
DIGESTIVE PROCESS: DIGESTION
2. Starting in the mouth, the mechanical and chemical breakdown of food is referred to as the process of digestion.
ACTIVATION OF PANCREATIC ENZYMES: TRYPSIN
2. The duodenum, in turn, will secrete enteropeptidase which will convert trypsinogen into trypsin.
PROXIMAL TO DISTAL THROUGH DIGESTIVE TRACT: UPPER ESOPHAGEAL
2. The upper esophageal sphincter separates the pharynx from the esophagus and regulates the passage of food into the esophagus.
Gastric
2. These reflexes stimulate gastric secretions.
PROXIMAL TO DISTAL THROUGH DIGESTIVE TRACT: LOWER ESOPHAGEAL
3. At the terminal end of the esophagus is the lower esophageal sphincter, which subconsciously controls the entrance of food into the stomach.
Pepsin
3. HCI will remove some amino acids from pepsinogen and turn it into pepsin.
DIGESTIVE PROCESS: ABSORPTION
3. Once foods are broken down into chemical monomers, the digestive system works to remove nutrients from the GI tract into the cells of the body via absorption.
STARCH DIGESTION FROM BEGINNING TO END: MALTOSE
3. The disaccharide, starch, is catabolized into maltose, which is then converted into glucose.
Hepatic Artery
3. The hepatic artery is responsible for delivering oxygen rich blood to the hepatocytes and thus providing for the large metabolic demand for this tissue.
PROTEIN DIGESTION AND ABSORPTION: CARBOXYPEPTIDASE
3. Then in the small intestine, trypsin, chrymotrypsin and carboxypeptidase continue the breakdown of proteins.
HCI
3. These secretions include gastrin, pepsinogen and HCI.
ACTIVATION OF PANCREATIC ENZYMES: PROTEINS
3. Trypsin will digest dietary proteins and also catalyzes the conversion of more trypsinogen into trypsin.
ACTIVATION OF PANCREATIC ENZYMES: ZYMOGENS
4. Finally, trypsin will also activate two other pancreatic zymogens, called chrymotrypsinogen and procarboxypeptidase.
STARCH DIGESTION FROM BEGINNING TO END: SMALL INTESTINE
4. Glucose can then be absorbed by the small intestine.
DIGESTIVE PROCESS: COMPACTION
4. Indigestible residues along with some of the non-reabsorbed secretions of digestive organs, undergo compaction where the fluids are removed and a remaining solid is created.
Autocatalytic
4. Pepsin will then be used in an autocatalytic effect and aid in the conversion of more pepsinogen.
Bile Ductules
4. The bile ductules collect bile produced in the hepatic lobules and deliver it to the hepatic ducts on their way to the galbladder for storage.
PROTEIN DIGESTION AND ABSORPTION: BRUSH BORDER
4. The brush border of the small intestine will finish the breakdown and begin absorption.
PROXIMAL TO DISTAL THROUGH DIGESTIVE TRACT: PYLORIC
4. The pyloric sphincter regulates the movement of food from the stomach to the small intestine.
Positive
4. This process will continue in a positive feedback cycle until the phase is complete.
Stomach
Pepsinogen; HCI; Intrinsic Factor.
Large Intestine
Rectum; Cecum; Ascending Colon; Transverse Colon; Descending Colon; Sigmoid Colon.
Buccal Cavity
Salivary Amylase; Lingual Lipase.
Chemical Digestion
Salivary Amylase; Pepsin; Hydrochloric Acid; Pancreatic Lipase.
Enteroendocrine Cells
Secrete hormones and paracrine messengers.
Parietal Cells
Secrete hydyochloric acid, intrinsic factor, and ghrelin.
Mucous Cells
Secrete mucus and predominate in the cardia and pylorus.
Chief Cells
Secrete the digestive enzyme gastric lipase and pepsinogen.
Aminopeptidase
Takes off one amino acid from the amine side of a peptide chain.
Carboxypeptidase
Takes off one amino acids from the -COOH side of a peptide chain.
Accessory Organ
Teeth; Salivary Glands; Liver; Galbladder.