Digestive System

Question 1

What are the parts of the Digestive System in order?

Answer 1

1) Mouth
2) Oesophagus
3) Stomach
4) Liver
5) Pancreas
6) Small Intestine
7) Large Intestine
8) Rectum

Question 2

What happens in the mouth?

Answer 2

Digestion begins as teeth chew and mix food with saliva (contains amylase, breaks down carbs).

Question 3

What happens in the oesophagus?

Answer 3

It links the mouth to the stomach.

Question 4

What happens in the stomach?

Answer 4

Food mixes with protease.
Muscular tissue in stomach wall churns food.
Hydrochloric acid kills bacteria and alters pH for protease.

Question 5

What happens in the liver?

Answer 5

Makes bile, which breaks fat into tiny droplets (emulsification).
Alkaline to give the right pH for the enzymes in the small intestine.

Question 6

What happens in the pancreas?

Answer 6

Glandular tissues in the pancreas produce insulin and enzymes:

PROTease digests PROTein
CARBOHYDRAse digests CARBOHYDRAtes
LIPase digests LIPids

Question 7

What happens in the small intestine?

Answer 7

Enzymes are used to digest protein, carbs and lipids.
Food is absorbed through the gut wall into blood stream.

Question 8

What happens in the large intestine?

Answer 8

Here water is absorbed.

Question 9

What happens in the rectum?

Answer 9

Undigested food is stored as faeces. Egestion takes place when faeces exits the anus.

Question 10

What is digestion?

Answer 10

Digestion is all about breaking down food.

Question 11

What are two types of breaking down food?

Answer 11

Breaking down the food MECHANICALLY, e.g. chewing with teeth.

Breaking down the food CHEMICALLY, with the help of proteins called enzymes.

Question 12

What are enzymes?

Answer 12

Enzymes are biological catalysts - they speed up the rate of chemical reactions in the body.

Question 13

What are the stages of digestion?

Answer 13

The stages of digestion are ingestion, digestion, absorption, assimilation, and egestion.

Question 14

What is ingestion?

Answer 14

Ingestion is the process of taking food, drink, or another substance into the body by swallowing or absorbing it.

Question 15

What is absorption?

Answer 15

Absorption is the movement of digested food molecules from the digestive system into the blood.

Question 16

What is assimilation?

Answer 16

Assimilation is the movement of the digested food molecules into the cells of the body from where they are used.

Question 17

What is egestion?

Answer 17

Egestion is the act of removing undigested food from the body.

Question 18

What are the four types of teeth?

Answer 18

Canines, incisors, molars, and premolars.

Question 19

What are canines used for and where are they located in the mouth?

Answer 19

Canines are positioned next to the incisors.
They are used for ripping apart meat.

Question 20

What are incisors used for and where are they located in the mouth?

Answer 20

Incisors are the teeth at the front of the mouth.
They are used for cutting through food.

Question 21

What are molars used for and where are they located in the mouth?

Answer 21

Molars reside at the very back of the mouth.
They have flat crowns and are used for chewing food.

Question 22

What are premolars used for and where are they located in the mouth?

Answer 22

Premolars are positioned before the molars.
They are used primarily for chewing food.

Question 23

What is peristalsis?

Answer 23

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.

Question 24

What happens to food molecules?

Answer 24

Food molecules are absorbed into the blood in the small intestine.

Question 25

Where are villi found?

Answer 25

The small intestine is lined with villi, tiny finger-like projections.

Question 26

How are villi good for absorbing food?

Answer 26

• They have a thin outer layer of cells
• They have a good blood supply
• They provide a large surface area for absorption