Digestive System

Front 1

Digestion

Back 1

The mechanical and chemical breakdown of food into smaller components that are more easily absorbed into the blood stream

Front 2

3 Main Purposes of Digestive System

Back 2

1. Digestion
2. Absorption
3. Elimination

Front 3

Alimentary Canal

Back 3

The organs forming a continuous tube from mouth to anus collectively

Front 4

Accessory Organs and Their Purpose

Back 4

1. Salivary Glands
2. Liver
3. Gallbladder
4. Pancreas
5. Appendix

Purpose: To secrete their respective products into the digestive tract

Front 5

Salivary Glands

Back 5

Secrete saliva containing the enzyme amylase to aid chemical digestion in the oral cavity (mouth)

Front 6

Amylase

Back 6

An enzyme contained within saliva which breaks down starch (carbohydrates) from polysaccharides to disaccharides

Front 7

Pancreas

Back 7

A digestive organ which secretes pancreatic juice containing digestive enzymes that assist the absorption of nutrients and digestion in the small intestine

Front 8

Liver

Back 8

Produces bile which is stored in the gallbladder and then transported to the duodenum via the common bile duct

Front 9

Emulsification

Back 9

The break down of large fat droplets into smaller fat droplets. This increases the surface area on which lipase enzymes can act

Front 10

Bile

Back 10

Aids digestion by emulsifying fats in the intestine

Front 11

Villi

Back 11

Minute finger-like projections which increase the surface area of the small intestine and are themselves covered with thousands of microvilli to further increase rate of absorption from this organ

Front 12

Oesophagus

Back 12

A soft, muscular tube which secretes mucus and transports food from the mouth to the stomach

Front 13

Peristalsis

Back 13

Muscular contractions of the walls of the oesophagus which move food along the digestive tract

Front 14

Stomach

Back 14

An expandable section of the gut which performs both mechanical and chemical digestion. It is where the break down of protein begins

Front 15

Pepsin

Back 15

An enzyme which is secreted initially as pepsinogen (inactive form) from the walls of the stomach and serves to digest protein molecules. Changes shape from inactive to active form due to the pH of the stomach

Front 16

Small Intestine

Back 16

Consists of:
1. Duodenum
2. Jejunum
3. Ileum
It is where the bulk of absorption occurs due to its large surface area and relies on secretions from the gall bladder, liver and pancreas to continue digestion

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Metabolism

Back 17

All chemical processes that occur within living organisms to sustain life

Front 18

Diffusion

Back 18

Movement of molecules from areas of high concentration to low concentration

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Absorption

Back 19

The passage of substances through cell membranes

Front 20

Diagram

Back 20

Front 21

Large Intestine

Back 21

Absorbs the remaining water from indigestible food matter and stores faecal material until excretion

Front 22

Carbohydrates

Back 22

Polysaccharides that largely consist of carbon, hydrogen and oxygen
- Building blocks: simple sugars (a.k.a monosaccharides and disaccharides)
- Example: starch

Front 23

Lipids

Back 23

Large polymer chains which are very energy dense as they have strong bonds which release a larger volume of energy when broken
- Building blocks: glycerol and fatty acids

Front 24

Protein

Back 24

Made up of large amino acid chains (polypeptides) which are held together by peptide bonds. When these larger amino acid chains are broken into smaller chains they become peptides
- Building blocks: amino acids
- Example: meat

Front 25

Denaturation of Proteins

Back 25

Proteins denature due to any factor that affects the polypeptide structure
E.g. temperature and pH