The Digestive System Flashcards
Ingestion
taking food in
Digestion
breaking food down
Absorption
Nutrients brought down into the blood and tissue
Egestion
getting rid of wastes
Alimentary canal + parts
The main pathway of the digestive system
- esophagus
- stomach
- small intestine
- large intestine
- rectum
- anus
Number of organs in the digestive system
10
Mesentery
Tissues supporting and positioning digestive organs
Function of the digestive system
Chemical and mechanical breakdown of food and the absorption of nutrients
Accessory organs
attached to the Ailementary can release enzymes, molecules and hormones that aid in digestion (liver, pancreas, gallbladder, etc.)
The mouth role in digestion
Begins digestion by physical breakdown of food (chewing)
and chemical breakdown (mixing with saliva)
Tongue
Moves food, lets you taste food
Palate
roof of oral cavity
Bolus
Partially digested food in the mouth
Mechanical breakdown
increases the surface area of food particles (chewing, crushing, stomach churning)
Chemical breakdown
Breaks food down into monomers using enzymes and water so they can be absorbed by the body
Salivary glands
Lets out saliva that carries the enzyme amylase
Amylase
An enzyme that breaks down starches into sugars
Pharynx
Back of the mouth
Epiglottis
Keeps food out of the airway
Esophagus
tube that carries food from your mouth to your stomach, using peristalsis to push the food along
peristalsis
the action of swallowing, where muscles around your esophagus that contracts and relaxes section by section to push food into the stomach
Stomach structure (see diagram in notes) - 8
- Fundus
- Longitudinal muscles
- Greater curvature
- Rugea
- Lesser curvature
- Pyloric sphincter
- Esophagus
- cardia sphincter
Stomach function
food storage and protein digestion, partially digests bolus into chyme
Secretory Cells
line the stomach wall producing gastric fluids, stimulated by the release of the hormone gastrin
Mucous cells
Secretory cell for protection
Parietal cells
Secretory cell of inactive pepsin
peptic cell
AKA pepsinogen: Secretory cell of active parental cell
Small intestine function
Chemical digestion (duodenum), absorption of nutrients into the bloodstream
Small intestine sections (see diagram in notes)
Duodenum
Jejunum
Ileum
Enzymes
Breaks down macromolecules with hydrolysis
Molecules
Aid in the digestion process
Hormones
stimulate digestive organs for nutrient absorption
Villi
Small bumps in the small intestine to increase surface area for absorption of nutrients
Absorption of carbohydrates
Glucose is actively transported into the intestinal wall to move into the bloodstream
Absorption of proteins
Amino acids are actively transported into the intestinal wall to move into the bloodstream
Absorption of lipids
Glycerol and fatty acids diffuse into the cells of the intestinal wall, where they get resynthesized into fats coated with proteins for eventual transfer into the bloodstream
Large intestine function
last chance for water and inorganic salt absorption, waste storage
Large intestine components (see diagram in notes)
- Cecum
- colon
- Rectum
- Anus
Cecum
start of the large intestine, appendix attached
Appendix
No known function other than bacteria storage and maybe synthesize vitamins B & K
Colon
Four sections: ascending, traverse, descending, and sigmoid
Rectum
Stores waste before it is expelled
Anus
Muscle sphincter that controls when waste exits
Pancreas function
Signaled by secretin, it releases bicarbonate ions into the small intestine to neutralize acidic chyme
trypsinogen
a pancreatic enzyme that converts to trypsin that breaks down proteins
Pancreatic Amylase
a pancreatic enzyme that breaks down starch
Pancreatic Lactase
a pancreatic enzyme that breaks down lactose
Pancreatic Lipase
an enzyme that breaks down fats
Liver Functions(3)
- The liver produces bile salts to emulsify fats
- Liver stores glycogen and vitamins
- The liver detoxifies substances in the body
Cholecystokinin (CCK)
A hormone produced in the small intestine that releases bile from the gallbladder
Gallbladder function
Stores bile salts used to digest fats
Bile
Fluid made by the liver
Bile salts
“detergent” that breaks fats into smaller pieces
Lipase
Breaks fat down into monomers
Gastrin
a hormone produced in the stomach lining that releases HCl into the stomach
Secretin
A hormone produced in the small intestine that releases sodium bicarbonate from the pancreas
Chemical digestion of macromolecules
See Chapter 6.2 booklet, last page
