Honors Biology Unit 3 - digestion

esophagus

esophagus

• tube with an entrance located at the back of the mouth, goes to stomach

• bolus travels down it to stomach through peristalsis

stomach

• where the food you eat first goes in the process of digestion (not in the digestive system, that is the mouth)

• highly acidic (very low pH)

• pepsin (breaks down proteins)

• mucus layer

small intestine

• where food (chyme) goes after stomach in digestive process

• enzymes from pancreas and gallbladder and liver are released into here to digest food

• amylase: starches

• trypsin: proteins

• lipase:fats

• folded lining covered in villi and microvilli

• absorption starts here with the microvilli absorbing carbs and proteins into cappilaries and fats and fatty acids being absorvbed into the lymph of the microvilli

nucleases

breaks down nucleic acids

lipases

breaks down fat

bile

breaks down salts and allows it to be broken down by water

alimentary canal

the whole digestive system

accessory organs

• Pancreas: produces enzymes (lipase, amylase & trypsin) and buffers (sodium bicarbonate) used by the small intestine. 

• Liver: produces bile.

• Gallbladder: stores bile and releases it into the small intestine

salivary glands

• produce saliva

• produce salivary amylase during ingestion and digestion

• facilitate swallowing, taste, chewing, speech, etc.

• part of chemical digestion

teeth

help with digestion

mechanical digestion

appendix

• stores good bacteria

rectum

• receives stool from the colon

• sends signals to the brain abt stool

glycosidases

breaks down glycosidic bonds

proteases

breaks down protein

ingestion

the process of taking food in

starts in the mouth

digestion

• starts in the mouth

• chemical: salivary amylase is released from the salivary glands in the mouth to break the chemical bonds of starches into sugars

• mechanical: chewing food into a bolus

• bolus moves down the throat and esophagus and enters the stomach where it is broken apart by acidic gastric juice

  • pepsin: proteins

  • mucus protects stomach

  • creates chyme

• goes to small intestine and mixes with chemicals from the liver (bile) and pancreas (lipase, amylase, trypsin)

• pancreas releases sodium bicarbonate (base) into small intestine which nuetralizes chyme (acidic)

absorption

• microvilli of the small intestine absorb the nutrients

  • carbohydrates and proteins by capillaries

  • fats and fatty acids into lymph

• the large intestine then removes water from the chyme

• bacteria produce some absorbable vitamins

elimination

final step in the digestive system

colon, rectum, anus

self-explanatory

pancreas

produces enzymes (lipase, amylase & trypsin) and buffers (sodium bicarbonate) used by the small intestine

liver

produces bile

gallbladder

stores bile and releases it into the small intestine

colon (large intestine)

he large intestine removes water from the chyme

peristalsis

The wave-like contraction and relaxation of smooth muscle tissue that moves “food” through the esophagus, stomach, small intestine and large intestine