Amanda DermerAmanda Dermer Keane ArchibaldKeane Archibald Dayana JimenezDayana Jimenez Courtney BlazerCourtney Blazer

Chapter 18: Lesson 1Chapter 18: Lesson 1 Eight GradersEight Graders Age: 13-14Age: 13-14

DigestionDigestion AbsorptionAbsorption EliminationElimination

Digestive SystemDigestive System

The purposeThe purpose define the define the

function of each function of each organ organ

the pathway the pathway food takes food takes through the through the digestive tractdigestive tract

Digestive SystemDigestive System

The organs and The organs and parts of the parts of the digestive pathway:digestive pathway: Oral cavityOral cavity PharynxPharynx EsophagusEsophagus StomachStomach Small IntestineSmall Intestine Large IntestineLarge Intestine

Digestive SystemDigestive System

TeethTeeth TongueTongue LiverLiver PancreasPancreas

The process that breaks down food The process that breaks down food into substances that can be into substances that can be absorbed by the body for energy, absorbed by the body for energy, growth, and repair. growth, and repair.

Ingestion:Ingestion:Mouth, Teeth & TongueMouth, Teeth & Tongue

The function of the The function of the mouth is to ingest food mouth is to ingest food sourcessources

The teeth are used for The teeth are used for mastication mastication breaking food down breaking food down

into smaller pieces to into smaller pieces to be be

The tongue forms food The tongue forms food into a ball to prepare for into a ball to prepare for swallowing swallowing

Ingestion:Ingestion:Mouth, Teeth & TongueMouth, Teeth & Tongue

The mouth, teeth, and tongue play a The mouth, teeth, and tongue play a role in mechanical digestion.role in mechanical digestion.

Mechanical digestion physically Mechanical digestion physically prepares food for chemical digestion prepares food for chemical digestion by enzymes.by enzymes.

Salivary GlandsSalivary Glands Secretes salivaSecretes saliva

a watery solution a watery solution containing an containing an enzyme that starts enzyme that starts the digestion the digestion

Cleanses the Cleanses the mouthmouth

Dissolves food Dissolves food chemicalschemicals

Moisten foodMoisten food

Salivary GlandsSalivary Glands

The salivary glands begin the The salivary glands begin the process of chemical digestion. process of chemical digestion.

PharynxPharynx

After leaving the mouth, After leaving the mouth, food is passed on to the food is passed on to the pharynx.pharynx.

As you swallow:As you swallow: Uvula: prevents food Uvula: prevents food

from passing into the from passing into the nasal cavity.nasal cavity.

Epiglottis: prevent food Epiglottis: prevent food from entering the from entering the respiratory tract.respiratory tract.

EsophagusEsophagus

Primary Function;Primary Function; Carry foods and Carry foods and

liquids to liquids to stomachstomach

Peristalsis Peristalsis moves food moves food though the though the digestive tractdigestive tract

Food passes Food passes through the through the pharynx into the pharynx into the esophagusesophagus Extends from the Extends from the

pharynx to the pharynx to the stomachstomach

StomachStomach

Located below the Located below the esophagus esophagus A hollow, saclike A hollow, saclike

organorgan Consists of three Consists of three

layers of muscleslayers of muscles Flexible, allowing Flexible, allowing

it to expand when it to expand when you eat. you eat.

StomachStomach

A temporary “storage tank” where A temporary “storage tank” where the chemical breakdown of proteins the chemical breakdown of proteins begin.begin.

The food is mixed together with The food is mixed together with gastric juices, secretions from the gastric juices, secretions from the stomach’s liningstomach’s lining containing pepsin and hydrochloric containing pepsin and hydrochloric

acid. acid.

StomachStomach As the stomach fills:As the stomach fills:

stomach contract stomach contract churn the food and churn the food and

gastric juices gastric juices togethertogether

This produces This produces chymechyme a creamy, fluid a creamy, fluid

mixture of food and mixture of food and gastric juices .gastric juices .

The passage of digested food from the The passage of digested food from the digestive tract into the circulatory system. digestive tract into the circulatory system. The small intestine is the major absorption The small intestine is the major absorption

site.site.

Small IntestineSmall Intestine

The major part of The major part of digestion and absorptiondigestion and absorption

20 to 23 feet in length20 to 23 feet in length Secretions from the Secretions from the

pancreas, liver, and pancreas, liver, and intestinal juices intestinal juices complete the chemical complete the chemical breakdown of all food. breakdown of all food.

Small IntestineSmall Intestine

Millions of Millions of fingerlike fingerlike projections called projections called villivilli

Each villus Each villus contains a network contains a network of capillaries which of capillaries which absorb digested absorb digested food particles from food particles from the small intestine. the small intestine.

Once food particles Once food particles enter the enter the capillaries in the capillaries in the villi, they are villi, they are carried throughout carried throughout the body by the the body by the blood.blood.

Peristalsis moves Peristalsis moves the chyme from the chyme from the stomach intothe stomach into

Small IntestineSmall Intestine

Three parts to the Three parts to the small intestinesmall intestine DuodenumDuodenum

Food enters Food enters here from the here from the stomach stomach

JejunumJejunum The middle The middle

section of the section of the SI SI

IleumIleum Allow one way Allow one way

flow into the flow into the large large intestine.intestine.

The Liver & PancreasThe Liver & Pancreas Liver: 2Liver: 2ndnd largest largest

organ in the body.organ in the body. Acts to clear the Acts to clear the

blood of toxins then blood of toxins then excreting them in excreting them in the bile.the bile.

Bile is a yellowish-Bile is a yellowish-green, bitter fluid green, bitter fluid important in the important in the breakdown of fats.breakdown of fats.

Liver & PancreasLiver & Pancreas

The pancreas produces 3 enzymes:The pancreas produces 3 enzymes: Trypsin, which digests proteinsTrypsin, which digests proteins Amylase, which digests carbohydratesAmylase, which digests carbohydrates Lipase, which digests fats Lipase, which digests fats Located in the C of the SI’s duodenum.Located in the C of the SI’s duodenum.

GallbladderGallbladder

Storage organ for Storage organ for bile produced from bile produced from liverliver

Located below the Located below the liverliver

The small intestine The small intestine stimulates the stimulates the release of bile into release of bile into the duodenum. the duodenum.

Not required for Not required for digestion digestion

Large IntestineLarge Intestine

Starts Ascending colonStarts Ascending colon Ends at the anus.Ends at the anus.

A.K.A. the colonA.K.A. the colon 5 to 6 feet long5 to 6 feet long

Large IntestineLarge Intestine

Unabsorbed materials: Unabsorbed materials: leave the small intestine in the form of leave the small intestine in the form of

liquid and fiber liquid and fiber enter the large intestineenter the large intestine

Absorbs most remaining Absorbs most remaining WaterWater VitaminsVitamins

The expulsion of undigested food or The expulsion of undigested food or body wastes. body wastes.

EliminationElimination

Harmless bacteria in Harmless bacteria in the large intestine the large intestine change the consistency change the consistency of the undigested food of the undigested food into a semisolid waste, into a semisolid waste, called fecescalled feces

Feces passes from the Feces passes from the body through the anus body through the anus

Termed “bowel Termed “bowel movement”movement”

Activity: Reconstructive Activity: Reconstructive SurgerySurgery

Lifestyle & Dietary Lifestyle & Dietary FactorsFactors

Eat at least 3 servings from a Eat at least 3 servings from a variety of fruits and vegetables to variety of fruits and vegetables to avoid constipation avoid constipation

Practice good hand washing Practice good hand washing hygienehygiene

Throw food away after it falls on the Throw food away after it falls on the floorfloor

Wash all foods before eatingWash all foods before eating Decrease caffeine consumptionDecrease caffeine consumption

Medications Medications

Some over the counter drugs that Some over the counter drugs that will help aid in the relief of will help aid in the relief of constipation and diarrhea.constipation and diarrhea. DiarrheaDiarrhea

a. Imodium ADa. Imodium AD

b. Pepto-Bismolb. Pepto-Bismol ConstipationConstipation

a. Citrucel a. Citrucel

b. Ex-Laxb. Ex-Lax

Stats of Constipation & Stats of Constipation & DiarrheaDiarrhea

Deaths due to Constipation & Diarrhea

Infectious Diarrhea

83%

Constipation17%

Infectious Diarrhea

Constipation

Create your own digestive tractCreate your own digestive tract

Each group will be representing a Each group will be representing a different part the digestive tractdifferent part the digestive tract

The group will stand in front of the The group will stand in front of the class and present the pathway of food class and present the pathway of food from ingestion to excretionfrom ingestion to excretion

Each person will state the organ Each person will state the organ they are and their functionthey are and their function

Be creative and have fun with the Be creative and have fun with the activityactivity