Human Nutrition

Question 1

Glands that aid digestion

Answer 1

• Liver
• Gall Bladder
• Pancreas
• Salivary glands

Question 2

Components of small intestine

Answer 2

Ileum
Duodenum

Question 3

Components of large intestine

Answer 3

Colon
Caecum
Appendix
Rectum
Anus

Question 4

Autotrophic

Answer 4

An organism that can make its own food(plants)
A type of nutrition

Question 5

Heterotrophic

Answer 5

An organism that cannot make its own food( all animals)
A type of nutrition

Question 6

Types of Heterotrophic nutrition

Answer 6

• Herbivores(animals that only eats plants)
• Carnivores(animals that eat other animals)
• Omnivores(animals that eat plants and animals)
• Parasites(feeds on live host causing them harm)
• Saprophytes(feeds on dead organic matter)

Question 7

What is the alimentary canal ?

Answer 7

Starts at the mouth ends at the anus

Question 8

What are the steps in human digestion ?

Answer 8

1. Ingestion: food enters mouth
2. Digestion: breakdown of food
3. Absorption: food is absorbed into the blood(by a process called diffusion)
4. Egestion: removal of unwanted food waste(not the same as excretion)

Question 9

What is digestion?

Answer 9

Digestion is the breakdown of food into smaller particles

Question 10

Why is digestion necessary ?

Answer 10

• To make food more souluble
• Allows food to be absorbed into the bloodstream

Question 11

Types of digestion ?

Answer 11

• Mechanical: physical breakdown of food
• Chemical: involves enzymes and stomach acid breaking down food

Question 12

Location of Mechanical and Chemical digestion

Answer 12

Mechanical: Mouth, oesophagus, stomach, duodenum
Chemical: Mouth, stomach, duodenum

Question 13

Mechanical and chemical digestion in mouth ?

Answer 13

• Mechanical: food broken down into smaller pieces by your teeth
• Chemical: The enzyme amylase(made in the salivary gland) breaks down food in the mouth.
• Startch>Amylase Ph7> Maltose

Question 14

Types of teeth

Answer 14

• Incisors: cut,slice and bite(chisel shape)
• Canines: tear and grip food(long and pointed)
• Premolars: crush and chew food(flat surface)
• Molars: crush and chew food (flat surface)

Question 15

Human dental formulae

Answer 15

2 (I 2/2 C1/1 P2/2 M3/3)= 32 teeth

Question 16

What is saliva

Answer 16

Saliva: softens and dissolves the food. Saliva consists of water and salts

Question 17

What is the oesophagus ?

Answer 17

Oesophagus: carries food from the mouth to the stomach during which it is digested mechanically

Question 18

What is peristalsis

Answer 18

• Peristalsis: Food is moved along the alimentary canal by the muscular action of peristalsis.
• Peristalsis helps breakdown food mechanical(physical)

Question 19

Role of fibre

Answer 19

• Fibre helps stimulate peristalsis
• Plant cell walls contain cellulose which provide us with fibre
• Fibre helps absorb water from large intestine

Question 20

Name two parts of the alimentary canal where peristalsis occurs that helps with mechanical digestion ?

Answer 20

Oesophagus and small intestine

Question 21

Stomach

Answer 21

• Muscular bags that stores food and digests food
• Churns food causing mechanical digestion
• Creates a mixture known as chyme
• Food enters and leaves the stomach through the sphincter muscle
• Stomach lining (mucosa) releases gastric juices

Question 22

What is in gastric juices?

Answer 22

• Mucous
• Pepsinogen
• Hdrochloic acid: kill harmful bacteria in the stomach

Question 23

How does the stomach prevent self- digestion ?

Answer 23

1. Mucous lines the stomach and is alkaline(basic) which reduces acidity (neutralises) near the stomach wall
2. Pepsin is released as inactive pepsinogen(so it doesn’t damage the stomach wall)

Question 24

Pepsinogen facts

Answer 24

• Pepsinogen is converted into active pepsinogen when reacting with an acid
• Proteins>Pepsin>Peptides
• Pepsin is a protease enzyme
• The end product of protein digestion is amino acids

Question 25

Glands associated with digestive system

Answer 25

- Salivary glands - Liver(linked to small intestine) - Pancreas (linked to small intestine)

Question 26

Location of the pancreas

Answer 26

Located behind the stomach in the upper abdomen

Question 27

Pancreas(gland)

Answer 27

- Secretes **sodium bicarbonate** into duodenum through pancreatic duct - **Sodium Bicarbonate neutralises the chyme** from the stomach in the duodenum(allows enzymes to digest food at the optimum pH) - Also releases **enzymes** amylase and lipase which are secreted into the duodenum to **help digestion** - Both these enzymes **work best at pH 7/8(optimum pH)**

Question 28

State two digestive functions of the pancreas ?

Answer 28

Releases enzymes and neutralises chyme

Question 29

Duodenum types of digestion

Answer 29

- Chemical digestion(enzymes) - Mechanical digestion(peristalsis)