Human Nutrition Flashcards
What are symbiotic bacteria?
Bacteria that are mutually beneficial
The bacteria get food in the intestine and in turn produce some B group vitamins.
The function of symbotic bacteria are?
Produce some B group vitamins and break down cellulose
Where in the human alimentary canal is the most water absorbed?
The large intestine
What is meant by the term digestion?
Digestion is the breaking down of food so that it can be absorbed into the bloodstream
Why is digestion necessary?
So that food can pass from the intestine into the bloodstream and be transported around the body to where its needed
Distinguis between mechanical and chemival digestion by writing a sentence about each.
mechanical = physical breakdown of food into smaller pieces - teeth
chemical = enzymes break down food into smaller molecules
State one digestive function of the pancreas
Produce amylase, which completes the digestion of starch into maltose
Name a substance transported to the liver by the blood in the hepatic portal vein
Co2 or named food
Name the blood vessel that brings oxygenaged blood to the liver
Hepatic artery
Where in the human body is the liver located in relation to the stomach?
Above stomach
To the right of the stomach
Behind the stomach
Where is bile stored after it has been made in the liver?
gall bladder
Give one role taht the bile salts play in the digestive process
Emulsify fats
Give further functions of the liver, other than manufacture of bile
1) storage of vitamins
2) cholesterol production
3) plasma protein production
A person who has suffered from constipation may be advised to increase the amount of wholegrain cereal in her/his diet. Why?
Fibre absorbs water
Faster digestive transit
Name a structure in the human digestive system, other than teeth, which is involved in mechanical digestion.
BILE, which is produced by the liver, emulsifies fat.
Describe two functions of bile in relation to digestion.
Emulsifies fats
Contains sodium hydrogen carbonate, which neutralises stomach acid
Answer the following in relation to lipase:
1) Where it is secreted?
2) Where does it act?
3) What is the approximate pH at its site of action?
1) secreted by pancreas
2) Duodenum
3) 7 to 8
Name the part of the digestive sytem in which the following are absorbed into blood.
1) products of digestion
2) water
1) the villi in small intestine
2) large intestine
Name a carbohydrate-digesting enzyme in the human alimentary canal.
Amylase
Where in the alimentary canal does the enzyme Amylase act?
The small intestine, duodenum
State the enzyme’s product (Amylase)
Maltose
State two ways in which VILLUS is adapted for the absorption of soluble fats.
- very thin walls, so that digested foods can pass through very easily
- very good blood supply
Name a process by which soluble foods are absorbed into blood from the small intestine.
DIFFUSION- the movement of substances from an area of high concentration (intestine) to an area of low concentration (blood)
What type of food is mainly absorbed into lacteal?
Fats- fatty acids and glycerol are absorbed into the lacteal
What is peristalsis?
Wavelike muscular contractions of the intestine
State one reason why a low pH is important in the stomach.
- kills germs
- optional ph for enzymes
Why is fibre important?
For peristalsis
Bulk for movement
Name an enzyme involved in the digestion of fat.
Lipase
What are products of fat digestion?
Fatty acids or glycerol
What is the role of bile in fat digestion?
Emulsification
State a role of benefical bacteria in the alimentary canal.
Production of vitamins/ aids digestion
Name two glands that pass their secretions into the small intestine.
Pancreas
Liver
