Digestive System

Describe protein digestion

-Amino acids are absorbed by contransport with sodium ions. -Some dipeptides and tripeptides are absorbed via contrasport with lt+ and hydrolized to amino acids within cells. -Amino acids leave the epithelial cells by facilitated diffusion, enter the capillary blood in the villi and are transported to the liver via the hepatic portal vein.

Describe fat digestion

-Fatty acids and monoglycerides enter the intestinal cells via diffusion. -They are then recombined to form triglycerides which combine with other lipids and proteins within the cells and the resulting chylomicrons which are extruded by exocytosis. -The chylomicrons enter the lacteals of the villi and are transported to the systemic circulation via the lymph in the thoracic duct. -Some short-chain fatty acids are absorbed, move into the capillary blood in the villi by diffusion and are transported to the liver via the hepatic portal vein.

Diverticulitis

-Inflammation of the diverticula which are sac like folds in the muscular lining of the colon. -Usually caused by a lack of fiber in the diet and is most common amongst the elderly. -Symptoms include severe cramping, diarrhea or constipation and flatulence. It can be reversed in most cases by increasing fiber in the diet but in severe cases, surgical removal of a section of the colon may be necessary.

What would the consequences be for the digestive system of a person who was not making enough salivary amylase.

-Salivary amylase begins starch (complex carbohydrate) digestion in the mouth. -Large carbohydrates like starch take a long time to break down, so it needs to start early in the process to be successfully broken down into glucose. -A person with too little salivary amylase would have a difficult time digesting complex carbohydrates. -This will cause digestive bloating, gas, diarrhea and stomach cramps. -They would need to take an amylase supplement to aleviate the symptoms.

Small intestine

90% of the digestion and absorption takes place in the small intestine.

Esophagogastroduodenoscopy (EGD)

A process in which an endoscope is inserted through the mouth to view the esophagus, stomach, and or duodenum.

Large Intestine

Absorbs water from indigestible food matter, and move waste products.

Absorption (digestive process)

Absorption is the mechanism by which digested end products are moved from the lumen of the GI tract into the blood or lymph.

Anus

Controls expulsion of feces

Rectum

Final straight section of large intestine.

Describe carbohydrate digestion

Glucose and galactose are absorbed via contransport with sodium ions. -Fructose passes via facilitated diffusion. -All monosaccharaides leave the epithelial cells via facilitated diffusion, enter the capillary blood in the villi, and are transported to the liver via the hepatic vein.

Gallbladder

Holds bile which helps in digestion of fatty foods.

Ingestion (digestive process)

Ingestion is the active, voluntary process of placing food into the mouth.

What are the six major processes involved in digestion?

Ingestion, Propulsion, Mechanical digestion, Chemical digesting, Absorption, defecation.

Mouth

Ingestion, propulsion, mechanical and chemical digestion

Chemical Digesting (digestive process)

Involves the sequence of steps by which large food molecules are broken down to their building blocks by enzymes.

Mechanical Digestion (digestive process)

Mechanical digestion involves all of the activities that break food down into smaller pieces to prepare them for further degradation by enzymes.

Stomach

Mechanical digestion/propulsion, chemical digestion and absorption.

Liver

Processes nutrients absorbed by the small intestine

Salivary gland

Produces saliva which assists in chemical digestion

Propulsion (digestive process)

Propulsion involves all of the actions involved in moving food along the alimentary canal from the mouth to the anus, including swallowing, peristalsis, segmentation, and mass movements.

Pharynx

Propulsion of bolus to stomach

Esophagus

Propulsion of the bolus to stomach

Pancreas

Releases hormones and enzymes for food break down.

Defecation (digestive process)

The final digestive process, which is the elimination of indigestible substances from the body via the anus as feces.

Colonoscopy

The process in which an endoscope is inserted through the rectum to view the colon