Digestive System Flashcards
Digestive tract pathway
Mouth-pharynx-esophagus-stomach-small intestine- large intestine- anus.
Accessory organ
Liver, gallbladder , pancreas
Mechanical breakdown of food
Chewing with teeth
Chemical breakdown of food
Tongue mixes food with saliva
Saliva
Thick fluid that lubricates and moistens food. Secretes lysozyme and amylase
Bolus
Smaller pieces of food that is broken down by being Chewed and saliva
Lysozyme
Enzyme that kills bacteria
Amylase
Digestive enzyme that breaks down carbs into simple sugars
*carbs are digested in the mouth
Pharynx
Tube that leads into 2 passageways - digestive and respiratory
Epiglottis
Small muscular tissue flap
Back digestive tract
Epiglottis folds downwards, food enters to the digestive tract
Front respiratory tract
When the epiglottis fold upwards, air enters to the respiratory tract
Esophagus
Long muscular tube
Upper 2/3 is voluntary muscle
Lower 1/3 is involuntary muscle
Actively moves a Bolus through peristalsis
Peristalysis
A rhythmical wave contraction to move food contents
Mechanical breakdown in stomach
Stomach wall has deep folds called RUGAE. Folds disappear as the stomach expands. Peristalysis still occurs.
Churning
Rotating motion as the food is digested. Digested food mixes with gastric juices and becomes chyme.
Chemical breakdown in stomach
Pepsinogen (inactive enzyme) reacts with Hcl. Pepsin is formed
Pepsin
Active, digested enzyme that breaks down proteins into amino acid.
*proteins are digested in the stomach
How much of the stomach is acidic?
2/3. Hcl Aides in protein digestion with pepsinogen. Kills bacteria
Small intestine
When phyloric sphincter contracts and relaxes, chyme passes into the duodenum of small intestine.
Long small diameter. Peristalysis still occurs. 3 parts- duodenum, jejunum, ileum.
Lipids digested here
Liver
Body’s largest internal organ.
Irregular shape
Helps maintain glucose concentration in blood by converting excess into glycogen
Bile
Produced by liver. Green fluid that contains hydrophobic and hydrophilic salts. Breaks up fats into fat droplets
Gall bladder
Small sac located at the underside of the liver. Stores bile
Pancreas
Secretes pancreatic juice and enzymes to the small intestines
Lipase
Digestive enzyme that breaks down lipids
Lipids digestion
Gallbladder releases bile through common bile duct. Enters small intestine.
Pancreas releases lipase through the pancreatic duct and enters the small intestines.
Bile and lipase breaks down lipids in the small intestines
What is epithelial wall of small intestine covered with?
Villi- finger like projections that contain capillaries
How does small intestine absorb nutrients?
Glucose, amino acids and fatty acids diffuse through the villi and enter the capillaries. Blood carries the nutrients and distribute to the tissues in the body.
Large intestine parts
Parts- cecum, ascending colon, transverse colon, descending colon,sigmoid colon, rectum, anus.
Large intestine
Larger in diameter but shorter in length. Peristalysis still occurs. Abosorbs water. Removed I digested food out of the body through the anus.
What is the digestive system
The breakdown of food and allows nutrients to be absorbed by the tissues in the body
