The Digestive SystemThe Digestive System

Perch DissectionPerch Dissection

Similarities and Differences in Organ Systems Compared to Humans?

SimilaritiesSimilarities DifferencesDifferences

GallbladderGallbladder Pyloric caecaPyloric caeca

LiverLiver Swim BladderSwim Bladder

PancreasPancreas

SpleenSpleen

Pyloric CaecaPyloric Caeca

Digestive System AnimationDigestive System Animation

►http://www.medtropolis.com/http://www.medtropolis.com/VBody.aspVBody.asp

Digestive System PartsDigestive System Parts

►MouthMouth► EsophagusEsophagus► StomachStomach► LiverLiver►GallbladderGallbladder► PancreasPancreas► Small IntestineSmall Intestine► Large IntestineLarge Intestine► Rectum and AnusRectum and Anus

MouthMouth

►Physical Digestion – chewingPhysical Digestion – chewing► 32 teeth32 teeth

12 molars, 8 premolars, 4 canines, 8 12 molars, 8 premolars, 4 canines, 8 incisorsincisors

► TongueTongue Taste buds distinguish between type of Taste buds distinguish between type of

foodfood Moves food around forming bolusMoves food around forming bolus

►Chemical Digestion – salivary amylaseChemical Digestion – salivary amylase

Teeth and Taste BudsTeeth and Taste Buds

EsophagusEsophagus

EsophagusEsophagus

►Receives bolus from the pharynxReceives bolus from the pharynx►Moves bolus to stomach by peristalsisMoves bolus to stomach by peristalsis

http://www.scoe.com/images/Esophagus1.jpg

StomachStomach

StomachStomach

► Receives bolus from the esophagus through Receives bolus from the esophagus through the lower esophageal sphincterthe lower esophageal sphincter

►Mixes the food with gastric juices containing Mixes the food with gastric juices containing HClHCl

►Mucus helps protect the stomach liningMucus helps protect the stomach lining► Pepsin - a digestive enzyme, helps break Pepsin - a digestive enzyme, helps break

down large protein moleculesdown large protein molecules► Creates a mixture called Chyme which is Creates a mixture called Chyme which is

moved through the pyloric sphincter to the moved through the pyloric sphincter to the small intestinessmall intestines

LiverLiver

LiverLiver►Releases bile which emulsifies fats and Releases bile which emulsifies fats and

help absorb fatty acids, cholesterol help absorb fatty acids, cholesterol and some vitaminsand some vitamins

►Stores carbohydrates and vitamins Stores carbohydrates and vitamins and detoxifies many harmful and detoxifies many harmful substancessubstances

http://www.healingdaily.com/conditions/cirrhosis-liver.jpg

GallBladderGallBladder

GallbladderGallbladder

►Stores bile that is produced by the Stores bile that is produced by the liverliver

►Gallstones – crystallized substances Gallstones – crystallized substances from bile in the gallbladderfrom bile in the gallbladder Can result in surgery to remove Can result in surgery to remove

gallbladdergallbladder

PancreasPancreas

PancreasPancreas

►Secretes digestive enzymesSecretes digestive enzymes►Neutralizes chymeNeutralizes chyme►Secrete Hormones:Secrete Hormones:► Insulin – lowers blood sugar levelsInsulin – lowers blood sugar levels►Glucagon – raises blood sugar levelsGlucagon – raises blood sugar levels

Small IntestineSmall Intestine

Small IntestineSmall Intestine► 9 to 10 feet long9 to 10 feet long►Composed of 3 parts : duodenum, Composed of 3 parts : duodenum,

jejunum and the illeumjejunum and the illeum►Most important absorbing organMost important absorbing organ►Digestion is completed in the small Digestion is completed in the small

intestineintestine

http://www.scoe.com/images/Stomach1.jpg

Large IntestineLarge Intestine

Large IntestineLarge Intestine

►Also called the colonAlso called the colon►Comprised of 4 sectionsComprised of 4 sections

Ascending, Transverse, Descending and Ascending, Transverse, Descending and SigmoidSigmoid

►Little or no digestive functionLittle or no digestive function►Chyme becomes feces which is stored Chyme becomes feces which is stored

until eliminationuntil elimination

Rectum and AnusRectum and Anus

Rectum and AnusRectum and Anus

►Rectum – temporary storage facility Rectum – temporary storage facility for fecesfor feces

► Internal and External sphincters allow Internal and External sphincters allow feces to be passed by muscles pulling feces to be passed by muscles pulling the anus over the fecesthe anus over the feces