Digestive System Flashcards
What are the parts of the Digestive System in order?
1) Mouth
2) Oesophagus
3) Stomach
4) Liver
5) Pancreas
6) Small Intestine
7) Large Intestine
8) Rectum
What happens in the mouth?
Digestion begins as teeth chew and mix food with saliva (contains amylase, breaks down carbs).
What happens in the oesophagus?
It links the mouth to the stomach.
What happens in the stomach?
Food mixes with protease.
Muscular tissue in stomach wall churns food.
Hydrochloric acid kills bacteria and alters pH for protease.
What happens in the liver?
Makes bile, which breaks fat into tiny droplets (emulsification).
Alkaline to give the right pH for the enzymes in the small intestine.
What happens in the pancreas?
Glandular tissues in the pancreas produce insulin and enzymes:
PROTease digests PROTein
CARBOHYDRAse digests CARBOHYDRAtes
LIPase digests LIPids
What happens in the small intestine?
Enzymes are used to digest protein, carbs and lipids.
Food is absorbed through the gut wall into blood stream.
What happens in the large intestine?
Here water is absorbed.
What happens in the rectum?
Undigested food is stored as faeces. Egestion takes place when faeces exits the anus.
What is digestion?
Digestion is all about breaking down food.
What are two types of breaking down food?
Breaking down the food MECHANICALLY, e.g. chewing with teeth.
Breaking down the food CHEMICALLY, with the help of proteins called enzymes.
What are enzymes?
Enzymes are biological catalysts - they speed up the rate of chemical reactions in the body.
What are the stages of digestion?
The stages of digestion are ingestion, digestion, absorption, assimilation, and egestion.
What is ingestion?
Ingestion is the process of taking food, drink, or another substance into the body by swallowing or absorbing it.
What is absorption?
Absorption is the movement of digested food molecules from the digestive system into the blood.
What is assimilation?
Assimilation is the movement of the digested food molecules into the cells of the body from where they are used.
What is egestion?
Egestion is the act of removing undigested food from the body.
What are the four types of teeth?
Canines, incisors, molars, and premolars.
What are canines used for and where are they located in the mouth?
Canines are positioned next to the incisors.
They are used for ripping apart meat.
What are incisors used for and where are they located in the mouth?
Incisors are the teeth at the front of the mouth.
They are used for cutting through food.
What are molars used for and where are they located in the mouth?
Molars reside at the very back of the mouth.
They have flat crowns and are used for chewing food.
What are premolars used for and where are they located in the mouth?
Premolars are positioned before the molars.
They are used primarily for chewing food.
What is peristalsis?
Peristalsis is the involuntary contraction and relaxation of muscles throughout the digestive tract. This pushes food. Dietary fibre increases the weight and size of faeces and softens it.
What happens to food molecules?
Food molecules are absorbed into the blood in the small intestine.
Where are villi found?
The small intestine is lined with villi, tiny finger-like projections.
How are villi good for absorbing food?
- They have a thin outer layer of cells
- They have a good blood supply
- They provide a large surface area for absorption
