Digestive system Flashcards
Digestive system function
to digest and absorb food and then excrete the waste products with the help of the liver, gallbladder, pancreas, small intestine, large intestine, and rectum.
Tract lined w epithelial tissue and absorbs nutrients and water, transporting them throughout the body.
Mouth
Where food enters
- Teeth chew food, physical change
Where ingestion begins
ORAL glands/ Salivia release amylase to break down carbs–> turn it into sugars
Tongue
Physical change - break food into smaller parts and move it into esophagus
Salivary glands
Chemical change - break food into smaller parts (make saliva)
saliva contains amylase
Pharynx(throat)
Swallow food - muscles push food into esophagus
esophagus
Part of tube, leads food into stomach through peristalsis - smooth muscle contractions
liver
Lots of functions, connects to circulatory system
- Produces bile to break down fats into fatty acids(stored in gallbladder)
- Processes and stores nutrients using lobules
- Breaks down food - eg carbs into sugar - and stores remaining nutrients
- Stores harmful substances in blood
Stomach
Acidic environment, main place where food breaks down through physical (peristalsis) and chemical digestion (HCl)
Sphincter muscles in stomach let food enter
Stomach also releases pepsin and to breakdown protein and amylase too to breakdown carbs
Gallbladder
Stores bile, eventually gives it to small intestine to break down food
Pancreas
Powerhouse enzyme maker (juice travel through pancreas via ducts into upper part of small intestine, etc)
Produces digestive juices and insulin (enzymes), also very important
Connect to diabetes
Creates and releases more enzymes/chemicals that help speed up breakdown of proteins lipids and carbohydrates
Produce hormones helping food digesting
Small intestine
Place where absorption happens - Where all broken down nutrients diffuse into the bloodstream to go to cells through microvilli thru capillaries and lacteals
Releases trypsin, bile and lipase to break down protein into amino acids and lipids into fatty acids and glycerol respectively
Large intestine
Absorb water and vitamins, changes waste into stool
rectum
Stores stool
Enzymes
proteins that help speed up metabolism, or the chemical reactions in our bodies. They build some substances and break others down. All living things have enzymes. Our bodies naturally produce enzymes.
amylase
found in mouth (saliva contains amylase) turns carb/starch into small sugars.
also found in small intestine, turn carbohydates into small sugars
pepsin
found in stomach, breaks down proteins into smaller peptides and amino acids.
trypsin
found in small intestine, breaks down proteins into amino acids
lipase
found in small intestine, breaks down lipids into fatty acids and glycerol respectively
what is digestive tract made of
lined w epithelial tissue that is made of goblet cells which secrete mucus to help protect and move food along
also has layers of msucle and nerves
absorptive cells
specialized cell of dig system and for absorption of nutrients across the apical plasma membrane
goblet cells
specialized
scattered among absorptive cells in epithelium of small intestine and colon–secretion of mucus which facilitates passage of material throughout bowel
taste cells
specialized for sensation of taste mediated by columnar epithelial sensory cells
hepatocytes
form and secrete bile, carbohydrate lipid and protein metabolism + detoxificaiton and immune cell activation to maintain liver homeotasis.
If an individual had stomach cancer, how their health be impacted?
The function of the stomach is to physically and chemically break down food. If the stomach cells are cancerous they are rapidly undergoing mitosis and not performing their function. IF the food is not effectively broken down by churning and corrosion by HCl, it will not have a high enough SA to volume ratio to be efficiently absorbed in the small intestine. Furthermore, enzymes like pepin would not be able to start breaking down proteins. Therefore a person with stomach cancer will not be able to effectively digest food which will potentially lead to blockages and ultimately lead to malnutrition.
