Sites of digestion mouth to duodenum

Question 1

Digestion in bucal cavity (mouth) 3

Answer 1

Food broken into small pieces by mastication
Moistened by saliva
Salivary amylase converts starch to maltose
Forms a bolus

Question 2

Mastication

Answer 2

CHEWING action of teeth

Question 3

Components of saliva

Answer 3

Water
Mineral salts
Mucus
Lysozyme

Question 4

Function of mineral ions in saliva

Answer 4

Maintain slightly alkaline confitions 6.5-7.5 for optimum functioning of salivary amylase

Question 5

Function of Mucus in saliva

Answer 5

Lubricates passage of bolus down oesophagus as it is swallowed

Question 6

Function of lysozyme in saliva

Answer 6

Kills bacteria (enzyme)

Question 7

Explain the function and process of peristalsis in the oesophagus

Answer 7

Propels food along the gut:
Behind bolus, circular muscles contract, longitudinal relax moving food

Question 8

Structure of stomach 5

Answer 8

Muscular sack
Rugae ridges
Cardiac sphincter
Pyloric sphincter
Goblet cells

Question 9

Function of rugae ridges in stomach

Answer 9

Aid in mechanical breakdown of food

Question 10

Function of sphincters

Answer 10

Cardiac relaxes at upper end to allow entrance of food into stomach
Pyloric relaxes at bottom end to allow exit of food into duodenum

Question 11

Function of goblet cells in stomach

Answer 11

Secrete mucus to protect stomach walls from enzymes and hydrochloric acid

Question 12

How many muscular layers does the stomach have, names and function

Answer 12

3:
Longitudinal
Circular
Oblique
Contract and relax to grind food

Question 13

Components of gastric juice found in stomach

Answer 13

HCl
Enzymes

Question 14

Function of HCl in gastric juice and what secretes it

Answer 14

Secreted by oxyntic cells
Kills MOST bacteria in food
provides optimum pH for enzymes
Activates pepsinogen

Question 15

Enzyme in gastric juice, inactive form, secreted by..

Answer 15

Pepsin: an endopeptidase
Released as inactive pepsinogen to avoid digesting the cells that secrete them
By chief cells

Question 16

Function of stomach 2

Answer 16

Mechanical digestion of food: grinding
Absorption of simple molecules e.g Alcohol and aspirin

Question 17

Function of the liver in digestion

Answer 17

Produces bile

Question 18

Where is bile stored+ next steps

Answer 18

Stored in gall bladder, enters duodenum via bile duct

Question 19

Function of bile

Answer 19

Emulsified lipids into smaller droplets to increase SA to increase Ro digestion
Neutralised stomach acid as it enters duodenum with the food

Question 20

What do glands in the submucosa of the duodenum secrete +function of secretions

Answer 20

Muscus for lubrication and protection
Alkaline juice which helps maintain optimum pH for functioning of enzymes

Question 21

What are the secretions of the pancreas and from where

Answer 21

Exocrine glands secrete pancreatic juice

Question 22

Components of pancreatic juice and functions

Answer 22

Endo and exopeptidases
Amlylase to hydrolyse remaining starch to maltose
Lipase to hydrolyse lipids to fatty acids and glycerol
Inactive trypsinogen

Question 23

How do secretions from the pancreas enter the duodenum

Answer 23

Via pancreatic duct

Question 24

From which organs does the duodenum recieve secretions

Answer 24

Liver and pancrease

Question 25

Explain the chemical digestion that occurs int he duodenum

Answer 25

Enzymes fixed in the membrane of the epithelial cells of the mucosa complete carbohydrate and protein digestion: Maltase: Maltose》glucose Dipeptidase: dipeptides》amino acids

Question 26

What secretes trypsinogen

Answer 26

pancrease

Question 27

What activates trypsinogen

Answer 27

Enterokinase

Question 28

What is the active form of trypsinogen

Answer 28

Tripsin

Question 29

What cells secrete rennin and pepsinogen in the stomach

Answer 29

cheif cells

Question 30

Components of bille

Answer 30

Bile salts, water, mucus