22-3 Your Digestive System -What organs make up your digestive system?? -What is the path that food Travels in your body??
Digestion Process of breaking down food into small molecules that can be used for energy Not all food is used for energy.
Mechanical vs. Chemical Digestion Mechanical= food is broken down into smaller pieces – Done in the mouth and stomach
Chemical = large molecules are broken down into smaller molecules through changes by different chemicals – Molecules will be absorbed after this – Found in mouth, stomach, + small intestine Both of these are used to release energy for the body
Major organs for this process are: – Mouth – Esophagus – Stomach – Small Intestine – Large Intestine – Rectum – Anus
Your Mouth JOB- food is cut into smaller pieces mechanical and chemical digestion occurs here.
Esophagus JOB- connect mouth and stomach Basically is a long tube (25 cm) that connects the stomach to the mouth.
Peristalsis- – waves of contractions by smooth muscles, move the food through the esophagus.
Stomach JOB= Food is turned into a soup (chyme) Mechanical (turns food) Chemical digestion (enzymes and acid) occurs Changes shape- when empty- is a long tube (hotdog/sausage), when full- expands in size.
Has Stomach Acid – Is very acidic- pH = 9, is Hydrochloric acid- – would eat away your stomach, but the stomach has lining to not let happen Food stays here for about 4 hrs.
Small Intestine JOB = Food is absorbed here Is very long (4m to 7m) Pancreas, liver, and gallbladder release enzymes into the small intestine
Inside of the small intestine has many ridges and folds= villi – This allows the food to be absorbed by the blood
Large Intestine Job= to absorb water from the chyme, causing chyme to turn to a solid form Chyme may stay in the large intestine up to 3 days to get the job done
Rectum + Anus Rectum- – Waste is stored here temporarily tell expelled Anus- – Waste leaves the body here
Minor Organs Appendix Liver Pancreas Gall Bladder Teeth Salivary Glands Tongue
Teeth – Cut/Tear food into smaller piece Salivary Glands – Make and store saliva Tongue – Moves the food around and helps a person talk
Liver – Makes bile Gall Bladder – Stores Bile – Found hidden in the liver Pancreas – Releases juices into the small intestine to breakdown and help food be absorbed – Hidden behind your stomach Appendix – Stores bacteria – Located off the large intestine
What are Enzymes? What is the role of Enzymes in our body?? Can anyone name a few examples of enzymes in the body.
Enzymes These are molecules that speed up reactions in our body Can reduce amount of energy needed or provide a place for the reaction to occur
Enzymes also help build molecules (besides just breaking them down) – Used in blood clots – Found in Muscle and nervous systems
Humans couldn’t exist if they didn’t have enzymes.
Saliva- – has amylase- this starts the break down carbohydrates Stomach- – has pepsin- this starts the break down of proteins
Enzymes -Insulin- -Released by the pancreas, -Allows glucose to be absorbed in the blood
Bile – Released by gallbladder – helps breakdown fats
Food Absorption Peristalsis helps food continue to move throughout the digestive tract Food molecules will start to move into the bloodstream by diffusion, osmosis, and active transportation
Once in the bloodstream they will go throughout the body- giving it energy
Good Bacteria in the Body Bacteria are heavily found in the large intestine. They break down cellulose (carbohydrate found in plants) – releasing several vit. and minerals
Bacteria and humans have a mutualism relationship