Digestive system

Question 1

Digestive system organs

Answer 1

• Mouth
• Pharynx
• Oesophagus
• Stomach
• Small and large intestine

Question 2

Accessory organs

Answer 2

• Salivary glands
• Pancreas
• Liver

Question 3

Optimal functioning of digestive enzymes depends on…

Answer 3

Temperature and pH of the environment

Question 4

Mouth

Answer 4

• Mastication
• Mixing food with saliva

Question 5

Functions of saliva

Answer 5

• Moistens the mouth to make swallowing easy
• Dissolves the food
• Salivary amylase which digests starch into disaccharides

Question 6

What is the digestive system responsible for?

Answer 6

• Ingestion
• Digestion
• Absorption
• Egestion

Question 7

Pharynx

Answer 7

Involuntary reflex of swallowing

Question 8

Oesophagus

Answer 8

Muscular tube that conducts food into the stomach by peristalsis

Question 9

Stomach

Answer 9

• Food storage
• 3 muscle layers (longitudinal, circular and oblique)
• Has 2 sphincters - cardiac and pyloric
• Secretes gastric juices

Question 10

Inner lining of stomach

Answer 10

Mucosa - Protects stomach from the acid and gastric juices

Question 11

Mechanical and chemical digestion in the stomach

Answer 11

Mechanical - Churning food into chyme
Chemical - Production of gastric juices
- HCl - Breaks down food, kills bacteria and converts pepsinogen into pepsin

Question 12

Cardiac sphincter

Answer 12

Door to the opening to the stomach located at the top which stops food going back up the oesophagus whilst relaxation allows food to enter

Question 13

Pyloric sphincter

Answer 13

Regulates movement of food and stomach acid to small intestine

Question 14

Small intestine

Answer 14

Digestion and absorption
- Muscular tube extending from pyloric sphincter to ileocecal
- 3 sections - duodenum, jejunum and ileum

Question 15

Duodenum

Answer 15

Receives enzymes secreted from the liver and pancreas

Question 16

Pancreas

Answer 16

Enzymes: trypsinogen, erepsin, pancreatic amylase and pancreatic lipase
Hormones: insulin, glucagon

Question 17

Digestion of proteins in the mouth

Answer 17

Proteins > Pepsin > Shorter chain peptides

Question 18

Digestion of proteins in small intestine

Answer 18

Trypsinogen > enterokinase > trypsin
Long chain polypeptides > trypsin > shorter chain peptides
Shorter chain peptides > erepsin (pancreas and small intestine) > individual amino acids

Question 19

Digestion of carbohydrates in the mouth

Answer 19

Carbohydrates > salivary amylase > disaccharides

Question 20

Digestion of carbohydrates in the small intestine

Answer 20

Carbohydrates > salivary amylase > disaccharides
Disaccharides > monosaccharides

Question 21

Digestion of lipids in small intestine

Answer 21

Fats > bile salts > small fat droplets
Small fat droplets > pancreatic lipase > glycerol + fatty acids

Question 22

Functions of liver

Answer 22

• Produces bile for fat digestion
• Detoxifies blood
• Metabolises carbohydrates, proteins and fats

Question 23

Liver and gall bladder problems

Answer 23

• Gall bladder stones
• Jaundice
• Liver cirrhosis

Question 24

Mechanical digestion in the small intestine

Answer 24

Segmentation - movement of food back and forth (different to peristalsis which propels food forwards)

Question 25

Chemical digestion in the small intestine

Answer 25

Secretions from small intestine, liver and small intestine's mucosa (erepsin)

Question 26

What does the small intestine do when digesting fatty meals?

Answer 26

Releases hormone that slows peristalsis which allows more time for fat digestion and absorption

Question 27

Absorption of minerals in the small intestine

Answer 27

Absorption of food occurs in small intestine - Villi increase the surface area, with microvilli on these further increasing surface area

Question 28

Large intestine absorption and egestion

Answer 28

- Chemical digestion is already complete - Large intestine houses bacteria to synthesise vitamins - Reabsorption of water, minerals and vitamins

Question 29

Liver

Answer 29

A large organ which makes bile that neutralises stomach acid

Question 30

Pancreas

Answer 30

A gland below the stomach which makes lots of chemicals called enzymes that help break down food.

Question 31

Pancreas function

Answer 31

- Produces digestive enzymes for macronutrients digestion - Secretes bicarbonate to neutralise stomach acid in the small intestine - Regulates blood sugar (insulin and glucagon)

Question 32

Stomach

Answer 32

A sack-like, muscular organ that is attached to the oesophagus. When food enters the stomach, it is churned with lots of acid

Question 33

Gall bladder

Answer 33

A small sac below the liver that stores and releases bile into the small intestine

Question 34

Gall bladder functions

Answer 34

- Stores and concentrates bile - Releases bile into the small intestine to aid in fata digestion

Question 35

Key takeaways: Digestion of carbohydrates

Answer 35

- Digest quickly for fast energy - Broken down into simple sugars

Question 36

Key takeaways: Digestion of fats

Answer 36

- Take the longest to digest (require bile and enter lymphatic system) - Broken down into fatty acids and glycerol

Question 37

Key takeaways: Digestion of protein

Answer 37

- Takes longer than carbs but not as long as fats - Broken down into amino acids

Question 38

Bile release from the gall bladder into the duodenum occurs under the stimulation of what?

Answer 38

CCK

Question 39

What is CCK and where is it released?

Answer 39

Small intestine Peptide hormone and neurotransmitter within the digestive processes to enable gall bladder contraction and promote satiety

Question 40

Large intestine functions

Answer 40

- Absorption of water and electrolytes - Absorption of vitamins liberated by bacterial action - Formation and storage of faeces

Question 41

Which enzyme is produces and released by the stomach?

Answer 41

Pepsin

Question 42

What is not secreted by the pancreas?

Answer 42

Pepsin