Digestive System

Question 1

Function of liver and gall bladder

Answer 1

Liver - produces bile

Gall bladder - stores vile and releases it into the S.I

Question 2

Structure of Digestive system (18 Things)

Answer 2

oral cavity, salivary glands, pharynx, liver, oesophagus, liver, gall bladder, stomach, pyloric sphincter, duodendum, pancreas, transverse colon, ascending colon. descending colon, caecum, appendix, small intestine, rectum, anus

Question 3

Function of Mouth, salivary glands, pharynx, oesophagus,

Answer 3

Mouth: chemical digestion of starch by saliva. Mechanical digestion of food by teeth (Mastication)
Salivary glands: produce saliva

Pharynx: moves up and back, ready for swallowing

Esophagus: carries food from the mouth to the stomach

Question 4

Function of Colons

Answer 4

absorbs, water, minerals, vitamins

Question 5

function of stomach, pyloric sphincter, duodendum and pancreas

Answer 5

Stomach: M.D - churning action. C.D pepsin.

Pyloric sphincter - regulates flow of material from stomach to duodendum

Duodendum: first part of small intestine

Pancreas: produces pancreatic juices containing enzymes fro digesting proteins, lipids and nucleic acids

Question 6

Function of small intestine

Answer 6

secretes intestinal juice. Lined with villi for absorption of digested food

Question 7

function of caecum, appendix, rectum and anus

Answer 7

Caecum - first part of large intestine

Appendix - stores useful bacteria, plays a role in immunity

Rectum - final part of large intestine in which faeces are formed

Anus - opening surrounded by the anal sphincter muscle that can be voluntarily controlled

Question 8

mechanical digestion

Answer 8

the mechanical breakdown of food into small particles.
Examples: Chewing of food with teeth(mastication). Churning of food in the stomach. peristalsis - oesophagus, S.I and L.I

Question 9

chemical digestion

Answer 9

the breakdown of food to small molecules by chemicals

Examples: Breakdown of starch in mouth by salivary amylase. Breakdown of food in stomach by pepsin.

Question 10

Teeth

Answer 10

4 incisors
2 canines
4 premolars
6 molars

Question 11

mucosa

Answer 11

internal lining of the stomach

specialised for secretion of gastric juices

Question 12

Chyme

Answer 12

made up of HCL, mucus and pepsin.

Pepsin - enzyme that works in very acidic solutions

HCl - allows protease to work and kills bacteria that enters stomach

Mucus - protects stomach from acidic chyme & bacteria
Prevents nutrient transfer at this stage of the alimentary canal

Question 13

absorption

Answer 13

nutrients are absorbed through the internal wall of the small intestine into the blood

Occurs in S.I

absorbs: monosaccharides, amino acids, fatty acids, glycerol, vitamins, minerals and water

Question 14

Absorption occurs via:

Answer 14

• Simple diffusion
• active transport

A.A, simple sugars, fatty acids & glycerol, water and water-soluble vitamins

Question 15

Small intestine - order

Answer 15

Duodendum - mixing bowl; acid neutralization. secretes alkaline mucus which neutralises HCl, lubricates s.i, creates a suitable pH level for chemical digestion and protects the wall of the duodenum

Jejunum - bulk of chemical digestion and nutrient absorption occurs here

Ileum - vitamin b12 absorption

Question 16

Intestinal juice

Answer 16

Clear to pale yellow, watery secretion released from the glands and mucous-membrane lining of the small and large intestines

Question 17

enzyme table

Answer 17

salivary amylase - mouth - starch - maltose

Pepsin - stomach - protein - polypeptides

Bile salts - liver, s.i - fat - fat droplets

Amylase, protease, lipase - s.i - starch, protein and fat - a.a, glycerol, maltose

Question 18

Emulsification

Answer 18

Bile produced by the liver but stored in the gall bladder.

• bile salts emulsify fat breaking it into small droplets
• contains no digestive enzymes

Question 19

Villi

Answer 19

made up of epithelium - one cell thick outer layer

blood capillary - surrounding the lacteal - absorbs a.a and glucose

lacteal - absorbs fatty acids and glycerol

Question 20

whether absorption is simple or active transpo

Answer 20

A.A - active - blood capillaries

Simple sugars - active - blood capillaries

Fatty acids and glycerol - simple diffusion - lacteal

Water - simple diffusion - blood capillaries

Water soluble vitamins - simple - blood capillaries

Question 21

Nutrients

Answer 21

Carbs - polysaccharide - disaccharide - monosaccharide/simple sugars

protein - polysaccharide - disaccharide - a.a

Lipids - small fat droplets - fatty acids & glycerol

Question 22

Digestive enzymes

Answer 22

Protease - breakdown proteins into a.a

Lipase - breakdown fats into fatty acids & glycerol

Amylase - breakdown carbs into simple sugars

Question 23

amylase

Answer 23

salivary - breakdown starch

Pancreatic - continues to breakdown polysaccharides

Intestinal amylase - breaks down maltose

Question 24

Protease

Answer 24

gastric - breaks down proteins

Pancreatic - breaks down polypeptides

intestinal - break down dipeptides

Question 25

Lipid

Answer 25

Pancreatic - tiny lipid droplets

Intestinal - tiny lipid droplets

Question 26

structure of l.i

Answer 26

caecum - site where s.i and l.i meet

ascending colon - RHS of colon moving up

Transverse colon - moving horizontally

Descending colon - LHS of colon moving down

Question 27

Oesophagus*

Answer 27

the tube that carries food from the throat to the stomach

Question 28

Pyloric sphincter*

Answer 28

a ring smooth muscle between the stomach and duodenum

Question 29

Elimination

Answer 29

removal of undigested food

Question 30

Stomach*

Answer 30

Pepsin degrades proteins to polypeptides

Question 31

Protein

Answer 31

s.i: trypsin degrades polypeptides to peptides

Peptides: degrade peptide to amino acids