Digestion

Question 1

Define Ingestion

Answer 1

the taking in of substances into the body through the mouth

Question 2

Define digestion (mechanical)

Answer 2

the breakdown of food into smaller pieces without chemical change to the food molecules

Question 3

Define digestion (chemical)

Answer 3

the breakdown of large insoluble molecules into smaller soluble molecules

Question 4

Define absorption

Answer 4

the movement of small food molecules and ions through the wall of the intestines into the blood

Question 5

Define egestion

Answer 5

the passing out of food that has not been digested or absorbed through the anus

Question 6

Role of fat - storage

Answer 6

Long-term energy storage
Insulate the body
Stored around vital organs
Store certain fat soluble vitamins

Question 7

Difference between alimentary canal and the digestive system

Answer 7

Alimentary canal: begins at the mouth ends at the anus
Digestive system: alimentary canal+ teeth+ salivary glands+ liver+ gall bladder+ pancreas

Question 8

Importance of chemical digestion in the alimentary canal

Answer 8

large insoluble molecules are broken down into smaller soluble molecules that can be absorbed and used by cells

Question 9

Digestion of starch in the alimentary canal

Answer 9

Starch- salivary amylase
Starch- pancreatic amylase
Maltose- maltase
glucose

Question 10

Function of the pharynx

Answer 10

contracts by muscular action to swallow bolus or push bolus to the oesophagus

Question 11

Function of the mouth cavity

Answer 11

Mechanical and chemical digestion

Question 12

Function of the epiglottis

Answer 12

flap which closes over the windpipe

Question 13

Function of the oesophagus

Answer 13

force food down through peristalsis

Question 14

Function of the sphincter muscle

Answer 14

Prevents food from passing back

Question 15

Function of the liver

Answer 15

Sore excess glucose
Breaks down excess amino acids

Question 16

Function of the colon

Answer 16

Absorb water
Compact indigestible residue into semi-solid faeces

Question 17

Function of the gall bladder

Answer 17

Store bile

Question 18

Function of bile

Answer 18

Neutralize stomach acid
Turn large fat globules to small fat droplets which increases the surface area for lipase

Question 19

Function of the salivary glands

Answer 19

Secrete saliva with water and mucus to soften and lubricate food
Contain salivary amylase

Question 20

What is a bolus?

Answer 20

Masticated food rolled by tongue into the pharynx into the oesophagus

Question 21

Function of the stomach

Answer 21

MD and CD
Churn and mix food with gastric juice
Some absorption
HCl destroy bacteria found in food
Contains pepsin

Question 22

Function of the pancreas

Answer 22

Secrete bicarbonate ions into the duodenum to completely neutralise and acids not neutralised by the bile

Question 23

Function of the small intestine

Answer 23

Absorption by villi
Absorption of water
CD and MD
Starch to Maltose to glucose

Question 24

Adaption of the villi

Answer 24

Finger-like projection: extended surface area
Micro-villi: increase surface area
Dense network of capillaries: absorption of digested nutrients
Single central lacteal: absorption of fat-soluble vitamins
Single layer of epithelial cells: faster diffusion of nutrients, may mitochondria for active transport of nutrients