The Digestive System By Chris Schneider

The Digestive System  Brings in food  Absorbs nutrients  Excretes waste

Digestive System Functions  Mouth  The beginning  Salivary glands are triggered by the smell of food and the saliva starts to digest the food in the mouth  “Juices” are produced to help with the digestion also

Digestive System Functions  Pharynx and Esophagus  Pharynx receives food from the mouth  Esophagus carries food to the stomach  Muscular tube from the trachea to the stomach

Digestive System Functions  Stomach  Stomach is a sac like organ with muscular walls  Stomach secretes acid and strong enzymes that continue the process of breaking down food

Digestive System  Small Intestine  Made up of three parts  Duodenum  Jejunum  Ileum  Breaks down food using enzymes from the pancreas and bile from the liver  Nutrients are absorbed into the walls

Digestive System Functions  Large Intestine (Colon)  Made up of Ascending Colon, Transverse Colon, the Descending Colon  The second part of the alimentary canal  Main function is to absorb water from the remaining indigestible food  Certain vitamins are taking through the walls  Processes waste so that excretion is easier

Digestive System Functions  Rectum  The rectum is an 8 inch chamber that connects the colon to the anus  Receives stool from the colon  Lets the person know there is stool to be evacuated  Holds the stool until evacuation happens

Digestive System Functions  Anus  The last part of the Digestion System  Consists of muscles that line the pelvis and two other muscles called anal sphincters  Provides control on stool

Digestive System Functions  Liver  Makes and excretes an important substance called bile  Processes the blood coming from the small intestine containing the nutrients absorbed  Purifies the blood

Digestive System Functions  Pancreas  Chief factory for digestive enzymes that are secreted into the duodenum  The enzymes break down proteins, fats, and carbohydrates

Digestive System Functions  Gallbladder  Storage sac for bile  Waits for signal to send more bile  Bile helps absorb fat in the diet  Bile also carries waste from the liver that cannot go through the kidneys

Digestive System  Organs that food passes through vs. the accessory organs  Accessory organs create the bile and enzymes needed to break down food  Organs that food passes through actually break down the food with the bile and enzymes from the accessory organs

Digestive System  Physical Digestion vs. Chemical Digestion  Physical Digestion  Starts with the cutting of food with a knife and fork  The teeth take over to grind food into small particles to be swallowed  Also includes paristalsis which is the churning of food down the digestive track  Chemical Digestion  Proteins, carbohydrates, and far molecules are too large to be absorbed into the blood steam so these chemicals break them down

Digestive System  Carbohydrate, protein, and lipid digestion  Proteins are digested in the stomach, fats in the small intestine, and carbohydrate digestion starts in the mouth, and continues in the upper stomache  Amylase digests carbohydrates in the mouth partially  Pepsin breaks down proteins in the stomach  Bile salts emulsify fats and oils into droplets, allowing enzymes to attack  Pancreatic juice might also enter the small intestine to help with digestion, and these include proteases, lipases, and amylases

Digestive System Disorders  Gastroesophageal Reflux Disease (GERD)  A chronic symptom of mucosal damge caused by stomach acid coming up from the stomach into the esophagus  Symptoms  Heart burn, Regurgitation, Trouble Swallowing  In western populations, the prevalence range for GERD is 10% to 20% of the population  Treatment  Diet  Avoid Smoking and Drinking  A number of medications are proved to treat GERD  Proton Pump Inhibitors  Antacids  Alginic Acid

Digestive System Disorders  Peptic Ulcers  Open sores that develop on the insides of your esophagus, stomach, and upper portion of the small intestine  Symptoms  Pain is the most common  Worse when your stomach is empty  Flare at night  Vomiting of blood  Prevalence Roughly matches age  i.e. 20 years old 20%, 80 years old 80%  Treatment Options  Antacids  Bismuth compounds  Prostoglandin Analogue

Digestive System Bibliography  PMH / PMH /  disorders/digestive-system disorders/digestive-system  /box/digestionweb/PhysChemlDigest.html /box/digestionweb/PhysChemlDigest.html  ulcer/DS00242/DSECTION=complications ulcer/DS00242/DSECTION=complications