The digestive system Flashcards
what is a tissue
a group of cells with a similiar structure and function
what is an organ
a group of tissues working together for a specific function
explain why the stomach is an organ
it consists of a group of tissues working together for a specific function
contains muscle tissue and glandular tissue (which release enzymes)
describe organs and their grouping
organs are grouped into organ systems which work together to form organisms
the digestive system is an example of what?
an organ system
what main nutrients does food contain?
carbohydrates(e.g starch), protein and lipids(fats)
where do molecules of carbohydrates protein and lipids go?
they are too large molecules to be absorbed by the bloodstream. So they have to be digested
what happens to the large molecules of carbs proteins and lipids during digestion?
the large food molecules are broken down into small molecules by enzymes . The small molecules then are absorbed into the bloodstream
what breaks down the large food molecules into small molecules?
enzymes
describe fully the order and functions of each organ in the digestive system
MOUTH- first food is chewed, enzymes in the saliva begin to digest the starch into smaller sugar molecules
OESOPHAGUS- food passes down the oesophagus and into the stomach
STOMACH- enzymes begin the digestion of proteins,
The stomach contains hydrochloric acid which helps the enzymes to digest proteins,
the food spends hours in the stomach
The churning action of the stomach muscles turns food into a fluid increasing the surface area for enzymes to digest.the fluid now passes into the small intestine
SMALL INTESTINE- when the fluid passes into the small intestine, chemicals are released into the small intestine from the liver and pancreas
PANCREAS- the pancreas releases enzymes which continue the digestion of starch and protein. They also start the digestion of lipids(fats)
LIVER-releases bile that speeds up the digestion of lipids and neutralises the acid released from the stomach(hydrochloric acid)
This fluid makes its way down the small intestine
WALLS OF SMALL INTESTINE- releases enzymes to continue the digestion of protein and lipids.
SMALL INTESTINE- small food molecules produced by digestion are absorbed into the bloodstream either by diffusion or active transport.
LARGE INTESTINE- the fluid makes it’s way through the large intestine, where water is absorbed into the bloodstream.
ANUS-finally the faeces is released from the body
what helps enzymes digest proteins in the stomach?
hydrochloric acid
where are chemicals in the small intestine released from?
the liver and the pancreas
what does the liver release?
what does this help with?
bile, speeds up the digestion of lipids, neutralises the acid released from stomach
explain the process molecules go though in the digestive system
large food molecules are digested into smaller molecules and then the products of digestion are absorbed into the bloodstream
what are the products of digestion used for?
they are used by the body to build new carbs,lipids and proteins
some fo the glucose produced is used in respiration
