digestive system

Question 1

major parts of the digestive tract

Answer 1

oral cavity
- pharynx
-esophagus
- stomach
- small intestine
- large intestine
- anus

Question 2

histological layers of the digestive tract

Answer 2

• mucosa : inner most layer secrets mucus
• sub mucosa : connective tissue layer contains blood vessels
• muscularis : 2/3 muscle layers movement and secretion
• serosa : outmost layer, holds tract together

Question 3

mouth function

Answer 3

• chew food and turn into bolus
• mechanical and chemical digestion

Question 4

oesophagus function

Answer 4

• transport bolus to stomach

Question 5

stomach function

Answer 5

• mechanical digestion - food churned
• chemical digestion - protein digestion

Question 6

small intestine function

Answer 6

chemical digestion of carbs, proteins and lipids by pancreatic enzymes
absorption of small molecules

Question 7

large intestine function

Answer 7

last chance for body to reabsorb any nutrients, bacteria in the large intestines produces vitamins and then faeces is formed. As more water is absorbed from the chyme the faeces becomes harder and is pushed towards the rectum

Question 8

three accessory organs of the digestive tract

Answer 8

• liver,
  gallbladder and pancreas

Question 9

liver function

Answer 9

breaks down fat and produces bile

Question 10

gall bladder function

Answer 10

stores bile which is then delivered to the duodenum

Question 11

pancreas function

Answer 11

produces digestive enzymes and pancreatic juices

Question 12

difference between digestion and absorption

Answer 12

digestion is the breakdown of foo into building blocks
absorption is when the building blocks are absorbed into the blood stream and delivered to the cells

Question 13

carbohydrates

Answer 13

• monosaccharides
• produce atp
• backbone of dna and rna

Question 14

protein

Answer 14

amino acids, peptide bonds
- regulate body functions, hormones and enzymes

Question 15

lipids

Answer 15

triglyerides (glycerol and 3 fatty acids)
- used to produce atp
- require more energy to break down

Question 16

recommended amounts of lipids carbohydrates and proteins

Answer 16

lipids 20-35%
carbohydrates 45-65%
proteins 10-35%

Question 17

stages of digestion

Answer 17

ingestion - intake of food
digestion - breakdown of food into building blocks. mouth stomach small intestine
absorption - building blocks are absorbed into the blood stream and delivered to cells, liver
cellular respiration - cells breakdown the building blocks to release energy

Question 18

function of bile

Answer 18

break down fat allowing enzymes to better access the lipids

Question 19

mastication

Answer 19

to chew food begin mechanical breakdown by breaking down food into smaller pieces allowing digestive enzymes to come into contact with greater surface area of food particles

Question 20

role of the tongue once food is in the mouth

Answer 20

• tongue pushed the bolus against the hard palate and then directed it to the pharynx and then into the oesophagus

Question 21

types of teeth

Answer 21

incisors, canines, premolars, molars

Question 22

number of each tooth and the role it plays in digestion

Answer 22

incisors 8 cutting
canines 4 tearing
pre molars 8 grinding
molars 12 grinding

Question 23

how does saliva contribute to digestion

Answer 23

saliva is composed of serous and mucous which helps lubricate the food for easier chewing and swollowing

Question 24

why is the small intestine so long

Answer 24

Make sure all nutrients are absorbed from the broken down food are absorbed into the blood, once in the blood they go to the cells where they are used to produce energy or form substances within the cell

Question 25

three subdivisions of the small intestine

Answer 25

duodenum
jujunum
ileum

Question 26

peristalsis

Answer 26

Involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system.The muscles ahead of the food relax and the muscles immediately after the food contract so the food is pushed into one direction

Question 27

enzymes

Answer 27

protein catalyst that speeds up the rate of specific reactions

Question 28

6 classes of nutrients

Answer 28

carbohydrates
lipids
proteins
vitamins
minerals
water

Question 29

vitamins

Answer 29

organic molecules
essential for metabolism can’t be produced by the body
eg vit c vit d

Question 30

minerals

Answer 30

inorganic nutrients
function - membrane potential and action potentials
- add mechanical strength to bones and teeth
available from plant and animal foods
eg iron zinc

Question 31

Role of epiglottis in swallowing

Answer 31

Closes off the larynx and trachea stopping food from entering the trachea and respiratory system

Question 32

How does saliva contribute to digestion

Answer 32

Lubricates the food for easier chewing and swallowing, contains enzymes which help breakdown carbohydrates

Question 33

Small intestines contain circular folds, vili and micdvili

Answer 33

to increase the surface area, the greater the surface area the greater the capacity for absorption of nutrients