human nutrition/digestive system

Question 1

define autotrophs

Answer 1

organisms that make their own food e.g plants + photosynthesis

Question 2

define heterotrophs

Answer 2

organisms that cannot make their own food e.g humans

Question 3

name the three types of heterotrophs

Answer 3

herbivores, omnivores, carnivores

Question 4

define digestion

Answer 4

the physical and chemical breakdown of food into simpler forms which are soluble in the bloodstreams

Question 5

what is mastication

Answer 5

chewing

Question 6

what are two benefits to physical digestion

Answer 6

increases surface area, makes food particles smaller and easier to swallow

Question 7

what is the alimentary canal

Answer 7

a long hollow muscular tube which runs through the body from the mouth to the anus

Question 8

name 7 parts of the digestive system

Answer 8

mouth, pharynx, oesophagus, liver, stomach, pancreas, gall bladder, bile duct, duodenum, ileum, colon, caecum, appendix, rectum, anus

Question 9

name the 5 stages of human nutrition

Answer 9

ingestion, digestion, absorption, egestion

Question 10

name the two ways digestion takes place in the mouth

Answer 10

physical breakdown by teeth, chemical breakdown by enzymes

Question 11

name two types of proteases

Answer 11

pepsin (stomach), trypsin(pancreas)

Question 12

name the 4 types of teeth

Answer 12

inscisors, canines, premolars, molars

Question 13

write down the dental formula

Answer 13

2( i2/2 c 1/1 p 2/2 m 3/3 )

Question 14

what is saliva made of

Answer 14

water, mucus, salivary amylase

Question 15

what does amylase do

Answer 15

breaks down starch into maltose… pH 7.5 needed

Question 16

what is the oesophagus lined with

Answer 16

circular muscles

Question 17

define peristalsis

Answer 17

rythmic relaxation and contravtion of circular muscles… pushes food along the oesophagus

Question 18

where does food enter the stomach from

Answer 18

through the cardiac sphincter muscle from the oesophagus

Question 19

what is secreted by the wall of the stomach

Answer 19

hydrochloric acid (pH1/2), mucus, enzymes

Question 20

how is the stomach protected from gastric juices

Answer 20

mucus lines the stomach, cells lining the stomach are packed tightly together + can be replaced very rapidly

Question 21

what is the name given to the churned food in the stomach

Answer 21

chyme

Question 22

what does chyme pass through to reach the duodenum

Answer 22

pyloric sphincter muscle

Question 23

what is the first part of the small intestine, the duodenum or the ileum

Answer 23

dudenum

Question 24

list the three sections of the small intestine

Answer 24

duodenum, jejunum, ileum

Question 25

name three adaptions of villi

Answer 25

numerous, large surface area, one cell thick

Question 26

name one place from which the duodenum recieves juices/

Answer 26

wall of the duodenum, liver, pancreas

Question 27

what does pancreatic juice consist of

Answer 27

water, sodium bicarbonate, enzymes

Question 28

name 3 pancreatic enzymes

Answer 28

pancreatic amylase, pancreatic lipase, pancreatic protease

Question 29

where do particles travel to after being absorbed into the blood

Answer 29

to the liver through the heptatic portal vein

Question 30

what is the journey of fatty acids and glycerol after absorption through the lacteal

Answer 30

travel into lymph system, return to the bloodstream in the left subclavian vein and finally are transported to the liver

Question 31

what does the heptaic artery do

Answer 31

carries oxygenated blood to the liver

Question 32

what does the hepatic vein do

Answer 32

carries deoxygenated, nutrient rich blood away from the liver

Question 33

what does the heptaic portal vein do

Answer 33

carries blood rich in nutrients from the small intestine to the liver

Question 34

what does bile consist of

Answer 34

water, bile salts, pigments

Question 35

whats the purpose of bile

Answer 35

emulsifies fats and neutralises chyme

Question 36

where is bile stored

Answer 36

gall bladder

Question 37

name 3 functions of the liver

Answer 37

prodction of bile, breakdown of dead red blood cells, detoxification of blood, storage of glycogen

Question 38

name the 4 parts of the large intestine

Answer 38

caecum, appendix, colon, rectum

Question 39

name 3 functions of the large intestine

Answer 39

absorption of water and mineral salts, waste becomes solid

Question 40

what example of symbiosis can be found in the colon

Answer 40

bacteria produce vitamin B and K, and get a place to live in return

Question 41

what is the importance of fibre in the diet

Answer 41

provides bulk (stimulates peristalsis), absorbs water prevents constipation, makes you feel full, prevents overeating

Question 42

what is a balanced diet

Answer 42

contains correct proportions of carbs, fats, protein, minerals, vitamins,water, fibre