Human Nutrition

Question 1

Name 4 accessory digestive organs

Answer 1

Tongue
Salivary glands
Liver
Gall bladder
Pancreas

Question 2

Function of mouth

Answer 2

Ingestion

Question 3

Function of tongue

Answer 3

Helps with chewing & tasting

Question 4

Function of salivary glands

Answer 4

Secrets saliva to break down the food

Question 5

Function of oesophagus

Answer 5

Takes food bolus from mouth to stomach by peristalsis

Question 6

Function of stomach

Answer 6

Breaks down food mechanically & chemically

- secrets hydrochloric acid (provides acid medium for enzyme action)

Question 7

Function of liver

Answer 7

Receives absorbed nutrients which it processes & stores
Makes bile
Breaks down toxic substances (alcohol, drugs & hormones)
Emulsifies fate

Question 8

Function of gall bladder

Answer 8

Stores bile

Question 9

Function of pancreas

Answer 9

Secrets pancreatic juices
Produces:
- insulin: decreases blood sugar levels
- glucagon: increases blood sugar levels

Question 10

Function of 3 parts of small intestine

Answer 10

Duodenum - receives bile & pancreatic juices

Jejenum - secretes intestinal juices

Ileum - area of most absorption & digestion

Question 11

Function of 3 parts of large intestine

Answer 11

Ileo-caecal valve - allows food remains into large intestine

Colon - re absorption of water

Rectum - storage of faeces

Question 12

Function of anus

Answer 12

Sphincter muscle controls egestion

Question 13

Name 5 processes of nutrition

Answer 13

Ingestion
Digestion
Absorption
Assimilation

Question 14

Ingestion ?

Answer 14

Food is taken into alimentary canal

Question 15

Digestion ?

Answer 15

Large insoluble molecules of food are broken down into small molecules

Question 16

Absorption?

Answer 16

The small molecules are absorbed into blood

Question 17

Egestion?

Answer 17

Indigestible food removed from body in the form of faeces

Question 18

Assimilation?

Answer 18

Absorbed nutrients are taken in the blood plasma to all body cells

Question 19

Name 3 ways of physical digestion

Answer 19

Chewing & tongue actions
Peristalsis
Churning in stomach

Question 20

Chewing?

Answer 20

Teeth have different shapes for different functions

Question 21

Tongue actions ?

Answer 21

Push food between teeth for chewing

Mixing food with saliva to form a bolus which it pushes into the pharynx for swallowing

Question 22

Peristalsis?

Answer 22

Alternating waves of contraction & relaxation of circular muscles in gut wall causing the bolus to be moved onwards

Question 23

Churning?

Answer 23

Food is further broken down by strong muscular contractions of the stomach wall until it forms a fluid called chyme

Question 24

What is chemical digestion?

Answer 24

The breaking down of large insoluble molecules into small soluble ones by a process called hydrolosis

Question 25

Hydrolosis?

Answer 25

Breaking down of food by hydrolases (enzymes) as a result of adding water

Question 26

Process by which fats are broken down into fat droplets

Answer 26

Emulsification

Question 27

Where does most absorption take place?

Answer 27

Small intestine

Question 28

Why is the surface area of small intestine so large ?

Answer 28

Very long
Walls with transverse folds
Transverse folds have numerous tiny finger-like projections (villi)
Villi are covered with cells with extremely tiny projections (microvilli)

Question 29

Name 3 adaptions of villus organs for absorption

Answer 29

Epithelium
- one cell thick
- rich supply of mitochondria
- secretes mucus
- microvilli
Rich supply of blood & lymph vessels to take up nutrients & transport them away
Has muscle tissue therefore can sway & ready all nutrients

Question 30

What blood vessel carries rich absorbed nutrients from villus to liver ?

Answer 30

Hepatic portal vein