6.2 - the digestive system Flashcards
alimentary canal
another name for the digestion system
how many organs make up the digestive system?
10
mesentery
a tissue that holds up and supports organs
peristalsis
muscles that move your food down your throat
villi
create a huge surface area for absorption
what is the function of the digestive system
mechanical and chemical breakdown of food and the absorption of nutrients
start of digestion
- mouth: physical breakdown of food
- tongue: moves food to the frenulum and roles food into a bolus
salivary glands (amylase)
- amylase is an enzyme that helps breakdown food into starch and sugars
the back of the mouth is called the
pharynx
a flap called the epiglottis ensures:
food does not go down the airway
esophagus
moves food to the stomach using peristalsis
the stomach is the site of _____ digestion
protein
starts at the ____ sphincter and ends at the _____ sphincter
- cardiac
2. pyloric
partially digested food is called:
chyme
secretory cells
- cells that line the stomach wall producing gastric fluids
- their release is stimulated by a hormone called gastrin
types of secretory walls
- mucous: for protection
- parietal cells: releases HCL
- peptic cells: pepsinogen (a protein digesting enzyme)
what is the difference between pepsinogen and pepsin
- pepsin is the inactive form of pepsinogen
- when the PH is above 3 it becomes active
What nerve carries info to the brainstream
vagus
cholecystokinin
tells you when your full
3 sections of the small intestine
- duodenum
- jejunum
- ileum
how does chemical digestion occur
Accessory organs (pancreas, liver, and gallbladder release enzymes, molecules, and hormones to aid in the chemical process)
- enzymes breakdown food
- molecules aid in the digestive process
- hormones stimulate digestive organs to release their enzymes
how is glucose transported
it is actively transported into the cells of the intestinal wall to move into the blood stream
how are amino acids transported
they are actively transported into the cells of the intestinal wall to move into the bloodstream
how are glycerol and fatty acids transported
they diffuse into the cells of the intestinal wall where they are resynthesizes into fats, coated with proteins and move into lymph vessels for eventual transport into the bloodstream
what is gastric bypass surgery
- making the stomach smaller
- rerouting the small intestine
- if you aren’t absorbing the nutrients you won’t put on weight
The large intestine (four components)
last chance for water absorption
- cecum: start of the large intestine attached to the appendix
- colon: 4 sections (ascending, transverse, descending, and sigmoid)
- rectum: stores waste before it is expelled from the body
- anus: muscular sphincter which controls the exit of waste
appendix function
may be used to synthesize vitamins B and K
what does cellulose (fibre) do in the large intestine?
provides bulk to the chyme
The pancreas
- works closely with the small intestine
- releases bicarbonate ions to the small intestine
- bicarbonate helps to neutralize the PH of the chyme
- releases the enzymes which help breakdown proteins, carbohydrates and lipids
- these enzymes are inactive until food is present
The liver
- produces bile salts
- storage of glycogen and vitamins
- detoxifies many substances in the body
Gallbladder
- stores bile and bile salts
- holds CCK (an enzyme)
Gastrin
- produced in the stomach lining
- releases HCL
Secretin
- produced in the small intestine
- causes the releases of sodium bicarbonate
