nutrition and digestion. animals ingest different types of food in a variety of ways – carnivores...

NUTRITION AND DIGESTION


• ANIMALS INGEST DIFFERENT TYPES OF FOOD IN A VARIETY OF WAYS– CARNIVORES– HERBIVORES– OMNIVORES– SUSPENSION FEEDERS– SUBSTRATE FEEDERS– FLUID FEEDERS– BULK FEEDERS

http://www.greatneck.k12.ny.us/GNPS/SHS/dept/science/krauz/bio_h/41_02WhaleEatSeal_VT.swf


• OVERVIEW: FOOD PROCESSING OCCURS IN FOUR STAGES


• OVERVIEW: FOOD PROCESSING OCCURS IN FOUR STAGES– INGESTION THE ACT OF EATING– DIGESTION THE BREAKING DOWN OF FOOD INTO

MOLECULES SMALL ENOUGH FOR THE BODY TO ABSORB• MECHANICAL DIGESTION VS CHEMICAL DIGESTION

– ABSORPTION THE CELLS LINING THE DIGESTIVE TRACK TAKE UP (ABSORB) SMALL NUTRIENT MOLECULES

– ELIMINATION UNDIGESTED MATERIAL PASSES OUT THE DIGESTIVE TRACT


• DIGESTION OCCURS IN SPECIALIZED COMPARTMENTS– GASTROVASCULAR CAVITY

A DIGESTIVE COMPARTMENT WITH A SINGLE OPENING • EX. HYDRAS


• DIGESTION OCCURS IN SPECIALIZED COMPARTMENTS– ALIMENTARY CANAL A TUBE BETWEEN TWO

OPENINGS (A MOUTH AND AN ANUS)• PHARYNX• ESOPHAGUS• CROP• STOMACHS AND GIZZARDS• INTESTINE• ANUS


• THE HUMAN DIGESTIVE SYSTEM CONSISTS OF AN ALIMENTARY CANAL AND ACCESSORY GLANDS


• MAIN PARTS– MOUTH– ORAL CAVITY– TONGUE– PHARYNX– ESOPHAGUS– STOMACH– SMALL INTESTINE– LARGE INTESTINE– RECTUM– ANUS


• DIGESTIVE GLANDS (ACCESSORY GLANDS)– SALIVARY GLANDS– PANCREAS– LIVER– GALLBLADDER


• DIGESTION BEGINS IN THE ORAL CAVITY– MECHANICAL DIGESTION TEETH– CHEMICAL DIGESTION SALIVA– TONGUE “BOLUS”• A BALL OF FOOD AND SALIVA MIXED TOGETHER


• THE FOOD AND BREATHING PASSAGE BOTH OPEN INTO THE PHARYNX– TRACHEA “WINDPIPE”• IN ORDER NOT TO CHOKE, THE TRACHEA MUST BE

COVERED TO PREVENT FOOD FROM BLOCKING IT• THANK GOD FOR THE EPIGLOTTIS

– SMALL FLAP THAT COVERS THE TRACHEA DURING SWALLOWING


• THE ESOPHAGUS SQUEEZES FOOD ALONG TO THE STOMACH– ESOPHAGUS

• A MUSCULAR TUBE THAT CONVEYS FOOD BOLUSES FROM THE PHARYNX TO THE STOMACH

• 2 LAYERS OF MUSCLE– CIRCULAR– LONGITUDINAL

• ACTION OF THESE MUSCLES IS INVOLUNTARY AND CAUSES PERISTALSIS– RHYTHMIC WAVES OF CONTRACTION OF SMOOTH MUSCLE IN THE WALLS OF

THE DIGESTIVE TRACT– THIS IS WHY YOU CAN SWALLOWING LAYING DOWN, OR EVEN DOING A

HANDSTAND!!!!!


• THE STOMACH STORES FOOD AND BREAKS IT DOWN WITH ACID AND ENZYMES


• THE STOMACH STORES FOOD AND BREAKS IT DOWN WITH ACID AND ENZYMES– GASTRIC GLANDS SECRETE MUCUS, HCl (PARIETAL CELLS),

AND PEPSINOGEN (CHIEF CELLS)• INACTIVE FORM OF THE ENZYME…WHY HAVE SUCH A THING??

– GASTRIN A HOROME RELEASED THAT STIMULATES SECRETION OF GASTRIC JUICE

– ACID CHYME A MIXTURE OF THE GASTRIC JUICE AND FOOD

– CARDIAC VS PYLORIC SPHINCTER• ESSENTIAL IN PREVENTING ACID FROM ESCAPING THE STOMACH

AND BURNING THE SMALL INTESTINES!!!


• SPEAKING OF BURNING– BACTERIAL INFECTIONS CAN CAUSE ULCERS!!

• GASTRICULCER OPENSORES IN THELINING OF THESTOMACH

– ESOPHAGEALULCERS A.K.A.HEARTBURN!!!


• THE SMALL INTESTINE IS THE MAJOR ORGAN OF CHEMICAL DIGESTION AND NUTRIENT ABSORPTION– THE SMALL INTESTINE WORKS IN CONJUCTION WITH

ACCESSORY GLANDS• PANCREAS

– PRODUCES DIGESTIVE ENZYMES AND AN ALKALINE SOLUTION TO NEUTRALIZE ACID CHYME

• LIVER (GALLBLADDER = BILE STORAGE)– PRODUCES BILE

» NOT AN ENZYME, BUT A DENSE LIQUID THAT EMULSIFIES (BREAKS INTO SMALLER PIECES) FATS AND MAKES THEM MORE SUSCEPTIBLE TO ENZYME ACTION


• THE SMALL INTESTINE IS THE MAJOR ORGAN OF CHEMICAL DIGESTION AND NUTRIENT ABSORPTION– BILE ACTION


• THE SMALL INTESTINE IS THE MAJOR ORGAN OF CHEMICAL DIGESTION AND NUTRIENT ABSORPTION– THE SMALL INTESTINE IS BROKEN UP INTO THREE

SEGMENTS• DUODENOM• JUJENUM• ILEUM


• THE SMALL INTESTINE IS THE MAJOR ORGAN OF CHEMICAL DIGESTION AND NUTRIENT ABSORPTION– MOST OF THE

INTERESTING STUFF HAPPENS IN THE DUODENOM (FIRST 25 CM)

– ACID CHYMEFROM STOMACHMIXES WITH BILEAND PANCREATICENZYMES


• THE SMALL INTESTINE IS THE MAJOR ORGAN OF CHEMICAL DIGESTION AND NUTRIENT ABSORPTION– THE INTESTINE IS LINED WITH VILLI


• THE SMALL INTESTINE IS THE MAJOR ORGAN OF CHEMICAL DIGESTION AND NUTRIENT ABSORPTION– THE INTESTINE IS LINED WITH VILLI

• SMALL FINGER-LIKE PROJECTIONS, LINE THE WALL OF THE SMALL INTESTINE

• INCREASE SURFACE AREA FOR MORE ____________• MICROVILLI

– LINE THE VILLI FOR EVEN MORE SURFACE AREA!!!

• LACTEALS– SPECIALIZED PROJECTIONS IN THE VILLI SPECIFICALLY DESIGNED FOR

LIPID (TRIGLYCERIDE/CHOLESTOL) ABSORPTION


• THE LARGE INTESTINE RECLAIMS WATER– LARGE INTESTINE = COLON• MAIN FUNCTION IS TO ABSORB WATER FROM THE

ALIMENTARY CANAL• APPENDIX

– SMALL, FINGER-LIKE EXTENSION; CONTAINS A MSS OF WHITE BLOOD CELLS AND HAS A MINIMAL ROLE IN IMMUNITY

• FECES– INDIGESTIBLE MATERIAL

• RECTUM– TERMINAL PORTION OF COLON WHERE FECES IS STORED


• ADAPTATIONS OF VERTEBRATE DIGESTIVE SYSTEMS REFLECT DIET


• ADAPTATIONS OF VERTEBRATE DIGESTIVE SYSTEMS REFLECT DIET– HERBIVOROUS ANIMALS HAVE LONGER DIGESTIVE

TRACTS– RUMINANT

MAMMALS HAVE A MORE ELABORATE SYSTEM FOR CELLULAR DIGESTION


• OVERVIEW: A HEALTFUL DIET SATISFIES THREE NEEDS– FUEL TO POWER ALL BODY ACTIVITES– ORGANIC RAW MATERIALS NEEDED TO MAKE THE

ANIMAL’S OWN MOLECULES– ESSENTIAL NUTRIENTS, OR SUBSTANCES THE

ANIMAL CANNOT MAKE FOR ITSELF FROM ANY RAW MATERIAL BUT MUST OBTAIN IN PREFABRICATED FORM FROM FOOD


• CHEMICAL ENERGY POWERS THE BODY– KILOCALORIES• THE ENERGY CONTENT OF FOOD MEASUREMENT

– BASAL METABOLIC RATE (BMR)• THE NUMBER OF KILOCALORIES A RESTING ANIMAL

REQUIRES TO FUEL THE ESSENTIAL PROCESSES FOR A GIVEN TIME


• A HEALTFUL DIET INCLUDES 13 VITAMINSA.K.A.COENZYMES


• ESSENTIAL MINERALS ARE REQUIRED FOR MANY BODY FUNCTIONS

• WHAT AREMINERALS?


• SO WE’VE BROKEN DOWN THE FOOD INTO SMALL ENOUGH MOLECULES TO BE ABSORBED INTO CELLS…BUT WHAT ELSE DO WE NEED TO ACCESS THE ENERGY STORED IN THOSE FOOD MOLECULES??

• RESPIRATION COMES NEXT!!!!

nutrition and digestion. animals ingest different types of food in a variety of ways – carnivores...

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