Human Digestive System

Question 1

heterotrophic

Answer 1

organisms that are not capable of making their own food

Question 2

autotrophic

Answer 2

organisms capable of making their own food using energy

Question 3

herbivore

Answer 3

eats plants only

Question 4

carnivore

Answer 4

eats animals only

Question 5

omnivore

Answer 5

eats both animals and plants

Question 6

photosynthesis

Answer 6

plants use light energy to make food

Question 7

chemosynthesis

Answer 7

use of chemical energy to make food

Question 8

saprophytic (decomposers)

Answer 8

organisms that obtain their food from dead organisms

Question 9

parasitic

Answer 9

two organisms of different species live together where one benefits and causes harm to the other

Question 10

symbiotic

Answer 10

organisms that live in close contact with a second species and at least one organism benefits

Question 11

egestion

Answer 11

removal of unabsorbed waste

Question 12

excretion

Answer 12

removal of waste products of metabolism

Question 13

peristalysis

Answer 13

rhythmic muscular contraction and relaxation in the wall of the alimentary canal causing the movement of food

Question 14

deamination

Answer 14

breaking down excess amino acids to form urea in the liver

Question 15

balanced diet

Answer 15

contains the correct amounts of each food type for good health

Question 16

stages of nutrition

Answer 16

ingestion: taking in food
digestion: physical and chemical break down of food into smaller molecules
absorption: food diffuses into the bloodstream
egestion: removal of unabsorbed waste

Question 17

types of digestion

Answer 17

mechanical: physical break down
chemical: addition of digestive enzymes

Question 18

why is digestion necessary

Answer 18

to make food soluble

easier to absorb/transport

Question 19

mouth

Answer 19

chemical: salivary glands produce saliva, amylase breaks down starch
physical: teeth, tongue

Question 20

type and function of teeth

Answer 20

incisors: cutting
canines: gripping and tearing
molars: crushing and grinding
premolars: crushing and grinding

Question 21

oesophagus

Answer 21

mechanical: peristalsis to move food from mouth to stomach

Question 22

stomach

Answer 22

location: abdominal cavity
mechanical: food churned to chyme
chemical:
digestive function - digestive enzymes break down food
defence function - hydrochloric acid and lysozyme produced to kill bacteria

Question 23

gastric juice

Answer 23

site of production: stomach
functions:
mucous: lines and protects stomach wall
HCI: kills bacteria, converts pepsinogen to pepsin
pepsin: breaks down proteins

Question 24

pancreas

Answer 24

location: abdominal cavity, below the stomach
functions:
digestive function: produces lipase,amylase
defence function: produces insulin

Question 25

digestive function can be called

Answer 25

exocrine function

Question 26

defence function can be called

Answer 26

endocrine function

Question 27

liver

Answer 27

location: above the stomach, upper abdomen
functions:
-makes bile
-helps detoxify the body
- deamination
-converts glucose to glycogen for storage
-stores vit and minerals

Question 28

bile

Answer 28

composition: water, bile salts, bile pigments
functions:
-emulsify fats
-neutralise chyme from stomach to provide optimum pH for enzymes

Question 29

gall bladder

Answer 29

location: liver
functions:
-stores bile
-releases bile into the duodenum through the bile duct

Question 30

small intestine

Answer 30

parts: duodenum, jejenum, ileum
functions: digestion and absorption

Question 31

duodenum function

Answer 31

chemical digestion using lipase and amylase

Question 32

ileum functions

Answer 32

absorb nutrients into bloodstream by diffusion

Question 33

ileum adaptations for absorption

Answer 33

1. long tube - allows time for reabsorption
2. villi - infoldings which increase the surface area available for reabsorption
3. walls are one cell thick - allows substances to diffuse easily into bloodstream

Question 34

how fat is absorbed from the small intestine

Answer 34

1. fatty acids and glycerol are absorbed into the lacteal
2. re form into fats
3. diffuse into bloodstream through blood vessels
4. peristalsis occurs at muscular wall

Question 35

hepatic portal vein

Answer 35

only vein not connected directly with the heart
connects ileum with liver
transports amino acids, glucose to the liver
amino acid broken down to urea
urea leaves the liver through hepatic vein

Question 36

large intestine/colon parts

Answer 36

caecum
appendix
rectum

Question 37

functions of large intestine

Answer 37

1. reabsorbs water
2. symbiosis:
   - bacteria feed on waste to produce vit B & K
   - break down cellulose, return nutrients to small intestine

Question 38

benefits of fibre

Answer 38

prevents constipation by stimulating peristalsis in colon

Question 39

constipation

Answer 39

too much water reabsorbed when undigested food moves too slowly

Question 40

amylase

Answer 40

produced in: salivary glands/pancreas
secreted to & active in: mouth/duodenum
pH: 7-9
role: digest starch -> maltose

Question 41

pepsin

Answer 41

produced in: stomach
secreted to & active in: stomach
pH: 2
role: digest protein -> peptides

Question 42

lipase

Answer 42

produced in: pancreas
secreted to & active in: duodenum
pH: 7-9
role: digest fats -> fatty acids and glycerol

Question 43

seven components of a healthy diet

Answer 43

carbs
proteins
fats
vitamins
minerals
water
fibre

Question 44

food requirements depend on

Answer 44

age
gender
health and activity levels