Miscellaneous
Nutrient that stimulates the muscles of the digestive tract
Fibre
found in the mouth
breakdown of food to increase surface area
Mechanical/physical digestion
sphincter muscles
Fuction of tongue
mix saliva and food / roll food into bolus/ push bolus down to oesophagus
Function of HCL in stomach
provides acidic pH for pepsin;
kills bacteria;
found in the stomachs of young mammals
Rennin
Egestion removes __________ .
undigested food / toxins/ dead cells
Tube that transports bile into the duodenum
Bile duct
sticky deposit on teeth causes gum disease
plaque
List three types of mechanical digestion in the alimentary canal
chewing in mouth, emulsification of fats by bile, churning in stomach
What is the optimum pH for pepsin?
2-3
Making nutrients as part of a cell
Assimilation
Structure that prevents food from entering the trachea
epiglottis
Components of saliva
Water, mucus/mucin, amylase
Two substances helps neutralise stomach acid in the duodenum
Where in the alimentray canal can Proteases be found?
stomach, duodenum and ileum
Describe peristalsis
wavelike muscle contractions which move food along the digestve tract (longitudinal and circular muscles)
Name two accesssory organs of the digestive system
Liver and pancreas
Three ways to stop tooth decay
Visit dentist twice a year;
Use fluoride toothpaste;
Brush teeth twice a day
Explain what happens when a cholera bacterium enters the alimentary canal
bacterium attaches to the walls of the intestines;reproduces; secrete toxins; Cl- from cells drawn into the lumen; water potential decreases in lumen, water moves into lumen by osmosis; cauing watery stool.
Describe how strach in bread is broken down throughout the alimentary canal until it is being absorbed.
in mouth- amylase bdwn starch to maltose;
in duodenum - same thing;
in ileum- maltase bdwn maltose to glucose
Desribe what happens after nutrients are absorbed into the villus to the capillaries?
Nutrient-rich blood is transported to the liver through the hepatic portal vein to be sorted before transported to other cells, stored or broken down.
Adaptation of villi (3)
1 cell thick - faster diffusion;
microvilli - increase surface area;
blood capillaries wrapped around villi - soluble nutrients aborbed;
lacteal to absorb digested fats
Describe the steps of tooth decay
sugary food trapped in cracks;
bacteria respires on sugar;
produces acid;
acid dissolves the enamel, dentine and lastly pulp cavity;
dissolves to the rootcausing an abscess