Human Nutrition

Question 1

Describe the functions of the following organs:
Mouth
Oesophagus
Stomach
Small intestine

Answer 1

Mouth - Where physical digestion and the breakdown of starch occurs
Oesophagus - where food is transported to the stomach
Stomach - where food mixed with enzymes and mucus
Small intestine - Where absorption and assimilation take place

Question 2

Give the 4 processes in which the digestive system deals with food

Answer 2

Ingestion - Taking of food into the alimentary canal
Digestion - Breaking down of food
Absorption - Absorption of nutrients into the blood
Egestion - Removal of undisgested food

Question 3

Define physical digestion

Answer 3

The breakdown of food into smaller pieces without chemical change. This increases the surface area of the food for enzyme action

Question 4

Give the 4 types of teeth and their functions

Answer 4

Incisors - Tearing of food
Molars - Grinding of food
Premolars - Similar to molars
Canines - similar to incisors

Question 5

Define chemical digestion

Answer 5

The breakdown of large insoluble food molecules into smaller food molecules

Question 6

Why is it important for chemical digestion to break down food molecules?

Answer 6

To increase their surface area, allowing for enzymes to be able to chemically digest them

Question 7

Describe the functions of these enzymes
Amylase
Proteases
Lipase

Answer 7

Amylase - Breaks down carbs
Proteases - Breaks down protiens
Lipase - Breaks down fats

Question 8

Where are amylase, protease and lipase found in the digestive system?

Answer 8

Amylase - The mouth and illeum
Proteases - The stomach
Lipase - The illeum

Question 9

Describe the digestion of starch

Answer 9

Amylase breaks down starch into maltose
Amylase breaks down maltose into glucose in the small intestine

Question 10

Describe the digestion of proteases

Answer 10

Pepsin breaks down protein in the stomach
Trypsin breaks down protein in the small intestine

Question 11

What is bile?

Answer 11

An alkaline mixture that neutralizes the acidic food entering the deodenum from the stomach

Question 12

What is the significance of villi and microvilli?

Answer 12

They increases the surface area, allowing food to be easier to absorb

Question 13

Describe the structure of a villus

Answer 13

Has an epithelium
Has goblet cells which secretes mucus
Has blood capillaries which absorb amino acids, glucose, vitamins, mineral ions and water
Has a lacteal which absorbs fatty acids and glycerol
Hepatic portal vein to transport blood to the liver