Digestive System

Question 1

Where does the human digestion start ?

Answer 1

At the mouth

Question 2

Define mastication and what is the importance of it

Answer 2

It is the mechanical digestion in the mouth where the teeth bites, chews and grind the food into smaller parts before it is swallowed and we chew the food mechanically so there is more surface area for further digestion

Question 3

What does saliva contain which lubricates the food making it swallow more easily

Answer 3

Mucus

Question 4

Where does starch digestion begin

Answer 4

In the mouth

Question 5

What is oesophagus? Define peristalsis movement

Answer 5

Oesophagus is the long tube which connects the mouth and the stomach and it helps the food travel down from the mouth to the stomach through peristalsis movement which is the repeated contraction and relaxation of the oesophagus circular muscles which contracts behind the bolus and the longitular muscles relax pushing the bolus to the stomach

Question 6

What enzyme helps in breaking down starch?

Answer 6

Amylase.

Question 7

What does hydrochloric acid do?

Answer 7

Helps in killing the microorganisms and providing the correct pH for the enzyme pepsin to work

Question 8

What is emulsification

Answer 8

It is when bile neutralizes the acidic chine coming from the stomach and then it breaks down the fat into tiny oil droplets

Question 9

What is churning

Answer 9

mechanical digestion in the stomach

Question 10

What is the digestion process in the mouth

Answer 10

Teeth lips and tongue helps in getting the food into the mouth this is called ingestion.
The teeth helps in chewing grinding and breaking the food into small parts for more surface area for further digestion. This is also known as mastication.
The tongue rolls the food into bolus
Starch digestion begins in the mouth.
The mouth has 3 salivary glands and the saliva has an enzyme called amylase which converts starch to maltose.
Saliva also contains mucus which lubricates the food helping it to swallow

Question 11

What is the digestion process in the stomach

Answer 11

Chemical and mechanical digestion takes place in the stomach, the mechanical digestion in the stomach is called churning.
The wall of the stomach produces a digestion called gastric juice and it contains 2 important substances which is hydrochloric acid and pepsin.
-hydrochloric acid helps in killing microorganisms and provide correct pH for the enzyme pepsin to work.
Pepsin acts on proteins and converts it into polypeptides.
The optimum temperature is 37 C and the optimum pH is 1.5 - 2

Question 12

What happens in the duodenum

Answer 12

It is the first part of the small intestine
It receives the pancreatic juice which contains protease lipase and amylase. Proteins, fats and starches are broken down into smaller soluble molecules.
Juice contains sodium carbonate (NaHCO3) which neutralizes the acid from the stomach producing a pH of 7 or 8

Question 13

What happens in the liver

Answer 13

The liver produces a juice called bile which is stored in the gallbladder and is carried by the biledut to the duodenum.
Bile neutralizes the acidic chine coming from the stomach and then break its fat into tiny oil droplets.
This process is also known as emulsification

Question 14

What happens in the pancreas

Answer 14

Pancreas releases a juice called the pancreatic juice and it contains all enzymes.

• amylase
• proteas
• lipase

Question 15

What is the function of amylase

Answer 15

It breaks the starches and carbs into sugar/ maltose

Question 16

What is the function of the lipase

Answer 16

It acts on lipids which are fats and oils, into fatty acids and glycerole

Question 17

What is the function of the protease

Answer 17

It breaks the proteins and turns it into amino acids