Digestive System

Major functions of the digestive system

Digestive enzymes

Major organs of the digestive system

Layers of GI Tract

Consists of organs that are involved in the breaking down of food into molecules that an pass through the wall of the digestive tract and can be taken up by cells

Esophagus- collapsible tube runs from pharynx to stomach, through diaphragm

Stomach- food enters the at the cardioesophageal sphincter

Pharynx- involved in deglutition

Small intestine- muscular tube extending from the pyloric sphincter

Mouth- opening into the oral cavity

Oropharynx- passage for food, water and air

Laryngopharynx- inferior to oropharynx

Where most chemical digestion of all foods occurs

Site of nutrient absorption into blood and lymphatic vessels

Large intestine- site of absorption of water and electrolytes

Anus- eliminates feces from rectum to exterior

Amylase- produced in the mouth and it helps break down large starch molecules into smaller sugar molecules.

Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids.

Trypsin, produced in the pancreas. Trypsin also breaks down proteins.

Pancreatic lipase, produced in the pancreas. It is used to break apart fats.

Stomach

Submucosa- arelor connective tissue containing major blood vessels

Mucosa membrane- produces mucus for reduction of friction and protection

Disorder of the Digestive System

Esophageal varices – bulging, engorged veins in the walls of the esophagus are often a complication of chronic alcoholism

Crohn’s Disease – a chronic inflammatory disease primarily of the bowel and some of the symptoms are abdominal pain, weight loss, diarrhea.

Diverticulosis/diverticulitis – Small pouches may form along the walls of the large intestine called diverticuli

Gastroesophageal Reflux Disease (GERD)- Weakness of the valve between the esophagus and stomach may allow stomach acid to reflux into the esophagus and irritate and inflame the lining.

Peritonitis – Inflammation of the lining of the abdominal cavity.

Muscularis layer- 2 layers of smooth muscles to allow peristalsis

Cardiac region- near heart

Fundus- dome shaped, filled with gas

Body- main portion

Pylorus- funnels shaped end

Pyloric sphincter- controls food leaving stomach and entering small intestine