Chapter 5: The Digestive System

Question 1

What is digestion?

Answer 1

The breakdown of large, insoluble food molecules into small water-soluble food molecules that can be absorbed into the watery blood plasma

Question 2

Mechanical digestion

Answer 2

Physically breaking down food into smaller pieces
This allows enzymes to act on a smaller surface area

Question 3

Chemical digestion

Answer 3

Breaking down foods into simpler nutrients through the use of enzymes and other substances

Question 4

What are the four main roles of the digestive system?

Answer 4

Ingestion
Digestion
Absorption
Egestion

Question 5

Ingestion definition

Answer 5

The taking in of food

Question 6

Digestion definition

Answer 6

The breaking down of complex organic molecules into smaller components by chemical and mechanical means

Question 7

Absorption definition

Answer 7

The taking up of digested molecules into the cells in the digestive tract

Question 8

Egestion definition

Answer 8

The removal of waste materials from the body

Question 9

Mouth and oesophagus

Answer 9

Chemical digestion - amylase digests carbohydrates
Mechanical digestion - chewing and swallowing

Question 10

Stomach

Answer 10

Chemical digestion - pepsin digestion of proteins
Mechanical digestion - peristaltic mixing and propulsion
Absorption - of lipid-soluble substances

Question 11

Small intestine

Answer 11

Chemical digestion - digestion of carbohydrates, lipids, fats, proteins and nucleic acids
Mechanical digestion - mixing and propulsion mostly by segmentation
Absorption - of peptides, amino acids, glucose, fructose, minerals and vitamins

Question 12

Large intestine

Answer 12

Mechanical digestion - segmental mixing, mass movement for propulsion
Absorption - of water, ions, minerals, vitamins and small organic molecules produced by bacteria

Question 13

Lower oesophageal sphincter

Answer 13

Regulates the food passing into the stomach and prevents the contents of the stomach from re-entering the oesophagus

Question 14

Pyloric sphincter

Answer 14

Governs the passage of food out of the stomach into the small intestine

Question 15

Regions of the small intestine

Answer 15

Duodenum
Jejunum
Ileum

Question 16

Bile

Answer 16

Made in the liver, stored in the gallbladder
Assists with digestion by breaking down fatty acids

Question 17

Mesentry

Answer 17

A fold of membrane that connects the intestine to the abdominal wall
It also stores fats and allows nerves, lymphatics and blood vessels to supply to the intestines