The Human Digestive System

Question 1

Which sequence correctly shows the path of food through the gut?

Accepted Answer

Mouth → oesophagus → stomach → small intestine → large intestine — Food passes from the mouth down the oesophagus to the stomach, then into the small intestine and finally the large intestine.

Question 2

What is peristalsis?

Accepted Answer

Waves of muscle contraction that push food along the gut — Peristalsis is rhythmic contraction of the circular muscles in the gut wall, moving food forward along the alimentary canal.

Question 3

Which organ produces bile?

Accepted Answer

The liver — Bile is made by the liver; it is then stored in the gall bladder before being released into the duodenum.

Question 4

The gall bladder mainly:

Accepted Answer

Stores bile — The gall bladder stores bile made by the liver and releases it into the small intestine when needed.

Question 5

The stomach adds which substances to food?

Accepted Answer

Protease and hydrochloric acid — Gastric glands in the stomach wall release protease (which digests protein) and hydrochloric acid, which provides the acidic pH the enzyme needs.

Question 6

Which structure produces amylase, protease and lipase?

Accepted Answer

The pancreas — The pancreas secretes pancreatic juice containing amylase, protease and lipase into the duodenum.

Question 7

In which part of the gut is most water absorbed?

Accepted Answer

The large intestine — The colon of the large intestine absorbs water from the undigested material, forming semi-solid faeces.

Question 8

The term 'egestion' means:

Accepted Answer

Removing undigested waste through the anus — Egestion is the removal of undigested food (faeces) from the body through the anus; ingestion is taking food in.

Question 9

Which part of the small intestine receives bile and pancreatic juice?

Accepted Answer

The duodenum — The duodenum is the first part of the small intestine; bile from the gall bladder and juice from the pancreas empty into it.

Question 10

What is the main role of the salivary glands?

Accepted Answer

To produce saliva containing amylase — Salivary glands release saliva into the mouth; it contains amylase, which begins the digestion of starch.

Salivary glands	Produce saliva (contains amylase).
Liver	Produces bile.
Gall bladder	Stores bile before it enters the duodenum.
Pancreas	Produces pancreatic juice (amylase, protease, lipase).

The alimentary canal

What each part does

Associated glands