Human Digestion Flashcards
Digestive system
- we have complete digestive system
- the tube our food is diested through is the G1 tract
- it is 7-9 m long
- it helps injest, digest, ejest and aboarb food
First part of digestion
- chemical and physcial digestion starts in mouth
- food is broken down with teeth
- caines and insiors tear down and cut food
- molors grind and crush food
- saliva breaks down food chemically
- the more u chew= more surface area= more reactions=more acid
saliva
- the enzyme amylase breaks down complex carbohydrates into disaccraides
- this enzyme also has mucus (protective lubricant) which helps swallow
- enzyme= biological calasyst (speeds up chemical reactions)
bolus
moist ball of food that is ready to be diesgted
swallowing food
- ingestion
- the touge pushes the food to the back of the mouth
- food goes into pharynx and soft pallet raises so food does not enter nasal cavity
- the epiglottis covers the entrance to your trachea (glottis) , food pushes it
- determintes if it goes to espohus or treachea
Esophagus
- pinches and pushes food
- espogus moves food to stomach
- long musclar tibe
- phyaynx is in bwteen oral and nasel cavity
peristalsis push
- wave-like muscle contractions that move food down
- takes 8 seconds
the stomach
- the gastroesophageal sphincter (cirlce peice of muslce) helps eneter food into stomach
- the j shape mucle oragan is the stomach that can expand (2L)
- foods mixes with gastic jusices (chyme) and gets sent to the pyloric sphincter
- spithcner closes
diesgtion in stomach
- chemical and physcial digestion
- muslce in stomach churns and breaks down food
- diestive exymes (pepsin) break down proteins
small intenstine
- where most diesgtion occurs
- diesgts lipds, carbs and proteins
- has three sections:
dudoudem: pacreases adds most enzymes and NaHO3 to nexturize stomach acid
jujunum: where digestion continues and some nurtirents are absorbed
ileum: where most nurtients are abosrbed
Order of digestive system
- Injestion
- DIgestion
- Absorbtion
- Egestion
Digestive tract
anything that touchs food
- mouth
- stomach
- espogous
- small/large intestine
- anus and rectum
Assesory organs
- Liver
- Pancreas
- gallbadder
pepisiogen
inactivated pepsin so it does not break down stomach acid
only activates in stomach acid (turns into pepsin)
pepsin does not harm stomach as musuc covers it
Absorption in the Small Intestine
the ineer surface of intestine is foled inward with finger-like projections called vili
Vili has mircovili inside them
this maximuses surface area, more low concentration, more absorpation (500x)
vili carrie snurtienst to blood stream
Transport in small intestine
Passive transport: No energy required
Activte transport: energy needed
passive transport
simple diffusion
-goes right through the meber (osomosis) (smaller)
facilitated diffusion
- more bigger molecules
- goes through membrane with help of transport protein
active transport
- goes againist concentration graident
- uses transport molecules and ATP
- goes from low to high concentratiom
large intestine
- cecum/apednix attach the small and large intestine
- colon is the largest part of intestine (acdenting, transverse, decending)
last part is rectum that holds feces until exterted by anus
Role of large intenstine
- absorbs water, ions and vitamins
- has 500 species of bacteria
- help to make gas, vitamin production and diesgtion of food
egestion
- removal of extra waste in the body
- made up of cellulose and fiber, which make us full for longer
- large intestine nerves feel the movment of food in rectum
- tells us to eject food through extrection
