Download THE HUMAN BODY

DIGESTION
• DIGESTION – BREAKING FOODS
DOWN INTO NUTRIENTS
– THEY ARE THEN CARRIED TO ALL
CELLS IN THE BODY BY BLOOD
– THERE THEY ARE USED TO PROVIDE
ENERGY AND THE RAW MATERIALS FOR
GROWTH AND REPAIR
THE MOUTH
• SALIVARY GLANDS – SALIVA –
MOISTENS FOOD IN THE MOUTH
• PTYALIN – BREAKS SOME STARCHES
INTO SUGAR
– PTYALIN IS AN ENZYME
– ENZYMES – CONTROL CHEMICAL
REACTIONS IN THE BODY
BOTH CHEMICAL AND MECHANICAL
DIGESTION TAKE PLACE IN THE
MOUTH
MECHANICAL DIGESTION
ACT OF PHYSICALLY BREAKING DOWN
FOOD
INCISORS
• FRONT TEETH
• CUT OFF FOOD
CANINES
• EYETEETH
• TEAR AND SHRED
MOLARS
• FLAT HEADED
• GRIND AND CRUSH INTO SMALL
PIECES
TASTE BUDS
• ON THE SIDES OF THE PROJECTIONS
OF THE TONGUE
• REACT TO CHEMICALS IN FOOD
– BITTER, SOUR, SWEET AND SALT
FLAVOR
MIX OF TASTE, TEXTURE, COLOR AND
ODOR
SWALLOW
• SMOOTH MUSCLES FORCE FOOD
DOWNWARD
• EPIGLOTTIS – SMALL FLAP
– CLOSES OVER WINDPIPE TO KEEP FOOD
OUT
– AFTER SWALLOWING, MOVES BACK TO
LET AIR IN
EPIGLOTTIS
ESOPHAGUS
TRANSPORTS FOOD FROM MOUTH TO
STOMACH
• LINED WITH MUCUS – HELPS FOOD
TRAVEL EASILY
• TAKES ABOUT 12 SECONDS FROM
MOUTH TO STOMACH
• PERISTALSIS – WAVES OF MUSCULAR
CONTRACTION THAT FORCE FOOD
THROUGH THE DIGESTIVE SYSTEM
STOMACH
J- SHAPED ORGAN
• GASTRIC JUICE IS RELEASED BY
CELLS IN THE STOMACH
– PEPSIN – ENZYME
– HYDROCHLORIC ACID – STRONG
ENOUGH TO BURN A HOLE IN A RUG
– MUCUS – COATS AND PROTECTS THE
STOMACH WALL
• MECHANICAL AND CHEMICAL
DIGESTION
– CONTRACTIONS IN STOMACH CHURN
FOOD AND MIX WITH GASTRIC JUICE
– HYDROCHLORIC ACID AND PEPSIN
BREAK DOWN SOME OF THE COMPLEX
PROTEINS INTO SIMPLER PROTEINS
SMALL INTESTINE
AFTER 3 – 6 HOURS IN THE STOMACH,
A SOFT, WATERY SUBSTANCE IS
PASSED INTO THE SMALL INTESTINE
• 2.5 CENTIMETERS IN DIAMETER
• MORE THAN 6 METERS LONG
• THE WATERY SUBSTANCE MOVES
THROUGH BY PERISTALSIS
• MOST DIGESTION TAKES PLACE
HERE
– CELLS LINING THE WALL RELEASE
INTESTINAL JUICE
• THIS CONTAINS SEVERAL TYPES OF
DIGESTIVE ENZYMES
• MOST CHEMICAL DIGESTION TAKES
PLACE IN THE FIRST 0.3 METERS
• JUICES FROM TWO OTHER ORGANS
HELP
– FOOD NEVER REALLY PASSES THROUGH
THESE ORGANS BUT THEY ARE
CONSIDERED DIGESTIVE HELPERS
LIVER
THE LARGEST AND HEAVIEST
INTERNAL ORGAN
• LIVER PRODUCES BILE THAT IS
STORED IN THE GALLBLADDER
• A DUCT ALLOWS THE GALLBLADDER
TO RELEASE BILE INTO THE SMALL
INTESTINE
• BILE BREAKS UP FAT PARTICLES
INTO SMALLER ONES
HUMAN LIVER
PANCREAS
LOCATED BETWEEN STOMACH AND
SMALL INTESTINE
• PRODUCES PANCREATIC JUICE
– PANCREATIC JUICE IS A MIXTURE OF
SEVERAL ENZYMES
– BREAKS DOWN STARCHES, PROTEINS,
AND FATS
• THE PANCREAS ALSO PRODUCES
INSULIN
– INSULIN CONTROLS THE BODY’S
SUGAR LEVELS
• AFTER 3 – 5 HOURS, MOST OF THE
FOOD IN THE SMALL INTESTINE IS
DIGESTED
• VILLI – LINE THE SMALL INTESTINE
• THE VILLI ABSORB FOOD
• MANY BLOOD VESSELS ARE
LOCATED IN THE VILLI TO
TRANSPORT THE FOOD
THROUGHOUT THE BODY
• WHAT REMAINS ARE UNDIGESTED
SUBSTANCES
– WATER, CELLULOSE, AND PARTS OF
FRUITS AND VEGETABLES
APPENDIX
• AT THE END OF THE SMALL
INTESTINE
• IT HAS NO KNOWN FUNCTION
LARGE INTESTINE
• SHAPED LIKE A HORSESHOE
• FITS OVER THE COILS OF THE SMALL
INTESTINE
• 6.5 CENTIMETERS IN DIAMETER
• 1.5 METERS LONG
• AFTER 18 – 24 HOURS IN THE LARGE
INTESTINE, MOST OF THE WATER IS
ABSORBED
• HELPFUL BACTERIA MAKE SURE
CERTAIN VITAMINS ARE ABSORBED
SOLID WASTE
• MINERALS NOT ABSORBED
• DEAD BACTERIA, SOME FAT AND
PROTEIN, UNDIGESTED ROUGHAGE,
DRIED-OUT PARTS OF DIGESTIVE
JUICES, MUCUS, AND DISCARDED
INTESTINAL CELLS
RECTUM
SHORT TUBE AT THE END OF THE
LARGE INTESTINE
ANUS
OPENING AT THE END OF THE RECTUM
WHERE SOLID WASTE IS ELIMINATED
GOOD HEALTH
• SUPPLY YOUR BODY WITH THE
MATERIALS IT NEEDS
• CONTROL YOUR WEIGHT
• GET PROPER EXERCISE AND REST
EXERCISE
• REGULAR EXERCISE STRENGTHENS
THE HEART
• FIRMER MUSCLES
• BETTER POSTURE
• GREATER STRENGTH
• INCREASED ENDURANCE
• IMPROVED SENSE OF BALANCE
WEIGHT CONTROL
• WHEN YOU EAT MORE THAN
NEEDED – EXCESS STORED AS FAT
• TO GET RID OF FAT – USE MORE
ENERGY THAN FOOD PROVIDES
OVERWEIGHT
• ALL ORGANS MUST WORK HARDER
• WEIGHT LOSS –
–
–
–
–
SEE A DOCTOR
BE SURE DIET IS BALANCED
REDUCE CALORIES
EXERCISE MORE