The Digestive System

The Digestive SystemThe Digestive SystemAlso called the:Also called the:

Gastrointestinal tract (GI tract)Gastrointestinal tract (GI tract)Alimentary canalAlimentary canal

Function:Function:Break down foodBreak down foodPrepare it for absorptionPrepare it for absorptionEliminate wasteEliminate waste

Mouth

Salivary glands

Stomach

Pancreas (behind stomach)Large intestine

Small intestine

Rectum

Gallbladder (behind liver)

Liver

Esophagus

Pharynx

The Process of DigestionThe Process of DigestionTwo types of digestion:Two types of digestion: Mechanical - physical breakdown of foodMechanical - physical breakdown of food Chemical - chemical breakdown of foodChemical - chemical breakdown of food

A.A. Oral (Buccal) cavity - The MouthOral (Buccal) cavity - The Mouth

1.1. Teeth – begins the mechanical Teeth – begins the mechanical digestiondigestion

2.2. Saliva – contains digestive enzymes Saliva – contains digestive enzymes that help begin the chemical digestive that help begin the chemical digestive processprocess

B.B. Hard palate – anterior roof of the mouthHard palate – anterior roof of the mouth

C.C. Soft palate – posterior roof of the mouthSoft palate – posterior roof of the mouth

PharynxPharynx – back of the throat – back of the throatEsophagusEsophagus – carries food from the pharynx to – carries food from the pharynx to

the stomachthe stomachStomachStomach – saclike structure located in the left – saclike structure located in the left

upper quadrant (LUQ) that is made of rugae upper quadrant (LUQ) that is made of rugae (folds) (folds) 3 main parts:3 main parts:

FundusFundus – upper part – upper part BodyBody-large central part-large central part PylorusPylorus-funnel shaped part at the lower -funnel shaped part at the lower

end of the stomachend of the stomach Chemical Digestion Chemical Digestion – hydrochloric acid and – hydrochloric acid and

enzymesenzymes Mechanical DigestionMechanical Digestion

Small IntestinesSmall Intestines• 20 foot long tube that extends from the pyloric 20 foot long tube that extends from the pyloric

sphinctor to the large intestinessphinctor to the large intestines• Consists of 3 parts:Consists of 3 parts:

• Duodenum – upper most part – approx. 10 Duodenum – upper most part – approx. 10 inches longinches long

• Jejunum – middle part - approx. 8 feet longJejunum – middle part - approx. 8 feet long• Ileum – lower part - approx. 12 feet longIleum – lower part - approx. 12 feet long

Digestion is completed here along Digestion is completed here along with enzymes from the pancreas with enzymes from the pancreas and liver and liver

Contains finger-like projections Contains finger-like projections called villi that aid in absorption called villi that aid in absorption of nutrients into the bloodstream of nutrients into the bloodstream

Small Intestine Villus

Circular folds

Villi

Epithelial cells

Capillaries

Lacteal

Vein

Artery

Section 38-2

Large IntestinesLarge IntestinesPassageway for waste products beginning at the Passageway for waste products beginning at the

end of the ileum and extending to the anusend of the ileum and extending to the anusAbout 5 feet in lengthAbout 5 feet in lengthFunction is to absorb water and minerals and Function is to absorb water and minerals and

eliminate wasteeliminate wasteCecum – 2-3 inchesCecum – 2-3 inchesAppendix – small appendageAppendix – small appendageAscending colonAscending colonTransverse colonTransverse colonDescending colonDescending colonSigmoid colonSigmoid colonRectumRectumAnus Anus

Liver

Gallbladder

Duodenum

Bile duct

Pancreas

Pancreatic duct

To small intestine

Section 38-2

Site

Mouth

Stomach

Small intestine(from pancreas)

Small intestine

Site

Mouth

Stomach

Small intestine(from pancreas)

Small intestine

EnzymeEnzyme Role in DigestionRole in Digestion

Section 38-2

Salivary amylase

Pepsin

Amylase

Trypsin

Lipase

Maltase, sucrase, lactase

Peptidase

Breaks down starches into disaccharides

Breaks down proteins into large peptides

Continues the breakdown of starch

Continues the breakdown of protein

Breaks down fat

Breaks down remaining disaccharides into monosaccharides

Breaks down dipeptides into amino acids.

Peptic Ulcer Disease (PUD)

•Open sore in the digestive tract caused by:•Action of the hydrochloric acid•Helicobacter pylori bacteria

•S/S•Heartburn, abdominal pain

•Tx•Antibiotics•Nonsteriodal anti-inflammatory drugs•Avoiding caffeine, smoking, and alcohol

http://www.youtube.com/watch?v=4bXZRgJ-1fk

Hernia

•Protusion of any organ, tissue, or structure through the wall of the cavity in which it is naturally contained•Inguinal - groin•Umbilical - umbilicus•Diaphragmatic - abdomen•Hiatal - abdomen•S/S

•Varies according to site•Tx

•Surgical repair

http://www.videomd.com/What-is-a-Hernia-fv-6871.aspx

Intestinal Obstruction

•Partial or complete blockage in the small or large intestines that prevents forward flow of digestive products caused by tumors, twisting of the intestines, scar tissue, etc.•S/S

•Abdominal pain, vomiting•Lack of bowel sounds

•Tx•Insertion of an intestinal tube•Surgery

http://www.youtube.com/watch?v=ZvudWuvMjtA

Hemorrhoids

•Enlarged veins in the anal canal caused by pressure from straining during bowel movements, pregnancy, prolonged sitting•S/S

•Bleeding, pain, itching•Tx

•Cold compresses•Stool softeners•Analgesic ointments•Surgical removal

http://www.youtube.com/watch?v=fQ18G5WIo-0

Hepatitis

•Inflammation of the liver•Hepatitis A - Infectious Hepatitis •Hepatitis B or C - Serum Hepatitis

•S/S•Hepatitis A – nausea, vomiting, diarrhea•Hepatitis B, C – possible flu-like symptoms, by may remain asymptomatic for years•Both - Jaundice

•Tx•Hepatitis A – no specific tx available •Hepatitis B- vaccination or immune globulin after exposure

Diverticulitis•Small, blisterlike pockets develop in the inner lining of the large intestines and may balloon through the intestinal wall•S/S

•Usually asymptomatic unless they become inflamed •Pain in the LLQ, extreme constipation, or diarrhea, fever, occasional blood in the stool

•Tx•Antibiotics•Soft diet•Surgery in severe cases

http://www.youtube.com/watch?v=lQTbYt6QFzM

http://www.youtube.com/watch?v=oLDJuZ9Ct7k