PowerPoint Presentation

Digestive System

Learning ObjectivesI can explain the overall importance of the digestive system in animals.I know what an enzyme is and what it does during digestion. I can list the different kinds of nutrients found in food and I know what each is used for in the body.I can explain how the food pyramid works and/or how to read it.

NOTEThere are a few differences in text on this PowerPoint slide show (compared to the student notes). These differences are in red italics. You are not expected to write these down on your notes, but listen and ask questions if it doesnt make sense! Digestion isThe process of breaking food into small molecules

Absorbing those small molecules/nutrients into the body..

NutrientsNutrients are substances in food that provide ENERGY and materials for cell development, GROWTH and REPAIR

The food pyramid suggests what food groups to eat and the size of the serving (the larger the slice = the bigger the serving you should eat). The new pyramid also emphasizes the importance of getting EXERCISE.

Food PyramidNOT IN 2013 STUDENT NOTES 6Nutrition by Brainpop

There are Two Types of DigestionMechanical digestion: breaking down food using physical forceExamples: chewing, mixing and churning.

There are Two Types of DigestionChemical digestion: breaking down food into smaller molecules through chemical reactions.

Examples: EnzymesAcidsBile

Enzymesare molecules that speed up the rate of chemical reactions

Enzymes

amylase is secreted in the mouth (in saliva). This enzyme breaks down STARCHES.

Starches = foods like bread, pasta, potatoes, riceEnzymes

PEPSIN is found in the stomach. It breaks complex proteins into less complex proteins

protein= foods like meat, eggs, nuts, legumes/beansEnzymesEnzymes are also responsible for MANY chemical reactions in your body---not just the ones involved in digestion!

Amylase only works on STARCHES

Pepsin only works on PROTEINSParts of the Digestive System

MouthFirst place food enters your body

Begins chemical & mechanical digestion

Different kinds of teeth do different kinds of job. Made of bone.

MouthWhich jaw belongs to a carnivore? (meat eater) ________Which jaw belongs to an herbivore? (plant eater) _______

What kind of teeth do humans have? Touch or examine yours!What kind of eater are we? OMNIVORES (we eat all kinds of foods)

a.b.a.b.

MouthGlands in the mouth produce saliva which contains amylase, which breaks down starch.SALIVA = 98% water + amylase + mucus, etc.

MouthTongue: used for chewing, tasting food (with taste buds) and talking

NOT IN STUDENT NOTES18CLIPS & ACTIVITIESTeeth by Brainpop

In the MouthMechanical & Chemical Digestion Clip

Place one marshmallow in the center of your tongue. DO NOT CHEW IT, ROLL IT AROUND OR SUCK ON IT. Just let the marshmallow sit on the middle of your tongue. Time how long it takes to dissolve in your mouth.

Which kind of digestion is this?Which enzyme is at work on this marshmallow?Why is it important that your mouth do both kinds of digestion? Amylase observation1chemical digestion2amylase because the enzyme works on starches and marshmallows are made of starch/sugar3it would be important because if your mouth only did chemical digestion, digestion would take a lot longer!20Learning Objectives I can explain the function of each digestive organ in the human body.I can identify the major parts of the digestive tract from a diagram. I know what an enzyme is and what it does during digestion. I understand how my digestive system helps me maintain homeostasis. I know which part(s) of the digestive system help to regulate my bodys internal environment.

EsophagusMuscular tube that connects throat to stomach

Moves food down by squeezing (peristalsis)

Peristalsis (pear-a-stal-sis): the squeezing of muscles and organs as food moves through the digestive tract22EsophagusThe epiglottis seals off your windpipe when you swallow so that food doesnt get into your lungs

23Other things back there

What are these things for?? Any ideas?Uvula = no real function, possibly a vestigial structure. Involved in gag reflex and possible speech sounds. Often removed for treatment of sleep apnea/snoring.Tonsils = part of your lymphatic system; filter lymph (body fluids) for germs. You can live without your tonsils!24Stomachmuscular bag where chemical and mechanical digestion continue

StomachMechanical digestion occurs through churning/ peristalsis

Not on students notes26STomachStomach acid and enzymes (pepsin) perform chemical digestion

Not on student notes27STomachfood stays here ~4 hours; changes to chyme(pronounced kime)

Yes, sometimes astronauts throw up!

Small Intestinetube nearly 7 meters long where digestive juices from the liver and pancreas are added to chyme

It is divided into 3 sectionsSmall IntestineVilli absorb molecules from chyme (increases surface area for absorption

Food molecules enter blood stream

30Small IntestineCHYME = partially broken down food

Duodenum = upper part of small intestine where food is still being broken down

31Pancreasa small, yellowish organ that produces substances that stop the action of stomach acidmakes enzymes that break down carbohydratesfood does NOT pass through the pancreas

LiverLarge reddish organ that filters the nutrient-rich blood (it is the largest internal organhas 4 lobes); has many other jobs

Produces a greenish substance called bile.

Bile breaks up large particles of fat into smaller particles.FOOD DOES NOT PASS THROUGH THE LIVER!

Gall bladdersmall sac that stores bile produced by liver

FOOD DOES NOT PASS THROUGH THE GALL BADDER!

Large intestineALSO KNOWN AS COLON

absorbs water from undigested food

unabsorbed materials become more solid

Large intestineshorter but larger diameter tubeappendix is offshoot of large intestinehelps the body maintain fluid balance (homeostasis)

Rectumwhere muscles control the release of waste from the body.

ANusopening where solid waste leaves the body

mouthLarge intestineliverpancreasGall bladderstomachesophagusSmall intestinerectumDigestive System by BrainpopDigestive System by Brainpop

) Where does digestion begin?

) What connects your mouth to your stomach?

) What is the duodenum?

) What is one organ that food doesnt pass through, that is still important in digestion?

Body Weight by BrainpopMetabolism by BrainpopEating Disorders by BrainpopThe Process of Digestion Clip (13 minutes)

Related Clipshttp://www.kitses.com/animation/swfs/digestion.swf

Animations