Transcript What makes a solid, solid?

What happens
when you swallow?
L/O ;- To be able to
label the digestive
system and explain the
function of each part
True or False
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Protein is important for growth
Iodine is used to test for protein
Carbohydrates are used for energy
Meat is a good source of protein
You should not eat any fat at all in your
diet
• Benedict solution goes orange when
there is sugar present
• Fibre is needed for insulation
What is digestion?
What organs do you think are
involved in digestion?
Lots of organs play a role in digestion, including:
Mouth
Stomach
Intestines
Anus
+ liver and pancreas (although food does not
pass through these)
(*appendix helps digest cellulose in some
animals, but has no real use in humans)
Mouth
Teeth break food up
and saliva starts to
digest food
Stomach
Hydrochloric acid
kills bacteria and
stomach juices
digest proteins
Liver
Produces Bile to help
digest fats
Small Intestine
Food is digested and
absorbed into the blood
Pancreas
Produces
enzymes
Large Intestine
Water is absorbed and
faeces compacted
Cows
• Why is it that cows have 4 stomachs?
• Cows, goats, sheep and several other animals
belong to a class of animals called ruminants.
Ruminants have four stomachs and digesting their
food in these stomachs, rather than in their
intestines.
• Ruminants eat food, regurgitate it as cud and eat
it again. The stomachs are filled with bacteria
that aid in digestion
• This is all because its difficult to break the grass
down and absorb the nutrients (cellulose cell
walls). It takes a long time to ‘process’ this food,
which is why they have four stomachs!
Rabbits
• Why do rabbits eat their ‘poo’?!
• This is a similar situation for the rabbits as it was
with the cows - its difficult to get all the nutrients
from the grass, as the cell wall (cellulose) is difficult
to break down
• For this reasons rabbits re-ingest their excrement,
helping get all the nutrients within
• In other words, the eat their poo to get a second
shot at absorbing all the nutrients they passed out
first time