DIGESTIVE SYSTEM Flashcards
what is left following the complex process of digestion?
waste products and fibre
how does the digestive enzyme called pancreatic lipase work?
It is water soluble and can only work at the surface of fat globules
digestion is greatly aided by emulsification.
What is emulsification and and what does it do?
it is the breaking up of fat globules into the much smaller emulsion droplets
What does salvia contain?
the digestive enzyme called salvary amylase
What does the digestive enzyme salvary amylase start the process of ?
a chemical breakdown of starchy carbohydrate into simpler sugars
True or false. There is no chemical breakdown of fat or protein in the mouth
TRUE
the pharynx is part of both the …. and the …..
name two
digestive and respiritory system
the pharynx’s muscular walls help to do what and where to ?
support the swallowing process and move food from the mouth to the oesophagus
because the pharynx serves as two different functions it contains a flap of tissue, what is the flap called ?
the epiglottis
the epiglottis acts as a swith to direct what to where
food to the oesophagus and inspired air to the larynx
what is the name given to the process of by which food is pushed into the oesophagus from the mouth to the stomach >
peristalsis
what is peristalsis and what does it do ?
it is rythmical waves of muscles contractions which help push food toward the stomach
no chemical breakdown takes place with peristalsis
TRUE or FALSE
TRUE
how long is an empty human stomach and what is the internal volume
only 15 - 30 cm long and internal volume of just 50 ml
what does the state of an empty stomach look like ?
it has deep muscular folds
how much can the stomach hold in litres of partly digested food
up to 4 litres
the smooth muscle fibres of the stomach are orientated into how many layers ?
3
food is broken down to a thick liquied called
chyme pronounced kyme
what is the role of pepsin in the stomach ?
it breaks the protein into smaller amino acid chains
What is the role of peptides and gastric lipase in the stomach
they will be released to break down short chain triglycerides into fatty acids and mono glycerides.
where can you also find tryglycerides
can be found in milk
acid secretion in the stomach is controled by what
nerve impulses
what hormone is acid secretion in the stomach controlled by
gastrin, which is produced by yet another gastric cell in response to nerve impulses
what is the digestive process also affected by and why
our emotional state
we can salivate when food is around
in individuals that produce too much acid or not enough mucus what can happen in the stomach
ulcers in the stomach wall
very little absorbtion occurs in the stomach, but name at least two things which can cross the lining of the stmach that can be quicly absorbed
alchol and asprin
how long does the churning and digestion take place in the stomach
up to five hours
what happens to chyme in the stomach in the digestive process ?
it is spurted in small amounts through a small opening called the sphincter
after the chyme is passed through the sphincter into the next part of the tract where does it go
the small intestine
how many parts is the small intestine divided into and name them
three
the duodenum
the jejunum and the
ilium
where is the major site for the digestion and absorbtion of nutrients
the small intestine
the name ‘small intestine’ is misleading, why
because it about 7 meteres i.e 25 foot long.
what is the role of the small intestine ?
break down the complex structure of nutrients into their useable components.
the liver plays a large part in digestion by doing what
secreting bile
what is the role of bile in digestion
bile emulsifies fat and provides correct environment for the breakdown and absorbtion of fats
what happens when the partly digested food enters the small intestine
it will be mixed with pancreatic enzymes that break down carbohydrates, protein and fat
it is the small intestines role to
transport nutrients into the bloodstream
what is on the surface area of the small intestine coveredwith
millions of villi and micro villi
the large surface are of the villi is covered with
What ? and what is its purpose
blood capilliaries
for the absorbtion of nutrients
At the center of the villi is the lacteal
What does the lacteal connect to
lymphatic system
the small intestine is also the major site for what ?
water absorbtion
the small amount of water that is NOT absorbed in the small intestine is passed to where ? or utilised for what ?
The large intestome and body or utilised for energy
what are three vital functions that water serves in the body
utilised for energy
efficient gut function
and
for the effective digestion and absorbtion of other nutrients.
what is insoluble fibre also known as
non-starch polysaccharide or N S P for short
does insoluble fibre (or N S P) disolve in water
NO
insoluble fibre (N S P) passes through the gut without being broken down, what does this ensure ?
helps other foods move through the digestive system more easily
insoluble fibre bulks up stools and helps to do what ?
and what is the benefit ?
makes waste move through the digestive tract more quicly
which in turn can help consitpation
Does soluble fibre disolve in water ?
Yes
does insoluble fibre (or non starch polysaccharide (N S P) disolve in water
no
where does soluble fibre disolve ?
the water of the digestive system
soluble fibre disolves in the water of the digestive system, what can this help with ?
it appears to help reduce the amount of cholestorol in the blood
although not fully known the exact mechanisms by which colesterol is lowered in the body it it thought
EXPLAIN
soluble fibres can be partly digested by the bacteria in the gut and some of the products of this absorbes here! only a very small amout will be excreted by the faeces
what is soluble fibre also known as ?
cellulose
the final stage of digestion happens where ?
and with what ?
the large intestine with the partial breakdown of cellulose (soluble fibre).
What is the role of the large intestine ?
reabsorbe the remaining water from undigested food
the undigested food and fibre in the large intestine ends up as what ?
faeces
what is the journey of the faeces from the large intestine ?
it passes to the colon and is then expelled from the body via the anul canal (rectum).
where is the liver located ?
to the right of the stomach just inferior to the diaphragmand superior to the small intestine.
how much does the liver weigh ?
and is the
what
largest organ in the body ?
about 3 pounds and is the second largest organ in the body
the liver has many different functions in the body but in digestion the main function is
EXPLAIN
production of bile acid and its secretion into the small intestine
what is the description of a gallbladder and where is the gallbladder located ?
small pear shaped organ located just posterior to the liver.
what is the role of the gallbladder ?
to store and recycle excess bile from the small intestine so that it can be reused for the digeston of subsequent meals
what is the pancreas ?
where is it located ?
and how long is it ?
it is a large gland, located just inferior and posterior to the stomach.
It is about six inches long
what is the role of the pancreas ?
it secretes digestive enzymes, including lipase (to break down of fat into fatty acids), amylase (to break down carbohydrates into glucose/sugar) and trypsin (to breakdown protein into amino acids) into the small intestine to complete the chemical digestion of foods.
what can fibre in the blood help with
cholesterol lowering effect
soluble fibre can help to ?
make stools more softer and easier to pass
some types of fibre can be fermented by gut bacteria helping what
to produce substances that appear to be good for gut health
soluble fibre (also known as fermentable fibre) is found in what ? give some examples for grains, fruits and beans/pulses and root vegetables
grains such as oats, barley and rye.
fruits such as bananas and apples
beans and pulses such as baked beans and chickpeas
root vegetables such as carrots and potatoes
insoluble fibre (also known as partly fermentable fibre) is found in what ?
and give some examples
g
cereal foods such as high fibre cereals. wholemeal bread and pasta brown rice and other whole grains. vegetables, potatoes with skins on and nuts and seeds
how can dietary fibre help support weight management ?
it can delay gastric emptying and lower the glycaemic index of high-modarate glycaemic index foods.
by lowering the glyceaemic index of high-moderate glycaemic index foods how will this make you feel and what wil it do ?
it may make your feel fuller for longer and present a slow steady release of glucose into the blood stream
how long does it take food to move through the entire digestive tract, depending on what
24 - 72 hours depending on what foods eaten and how much
how long can meat and fish take to move through the entire digestive tract ? and why does it take this amount of time ?
as long as two days to fully digest due to the complex protein and fat molecules
how long does it take for fruit and vegetable to fully move through the digestive tract ? and why this amunt of time ?
in less than a day as they contain fibre
how long does it take for processed food to move through the entire digestive tract
can be digested in a matter of hours
the rate at which food can be fully digested can vary according to the following factors
name three
gender
metabolism
and any digestive issues that could slow down or speed up the process
Initially food will travel relatively quickly through the digestive system. state how long and the process
within 6 to 8 hours food will have moved through:
the stomach
small intestine
large intestine
once in the large intestine how long can the partially digested food sit there ?
for up to 72 hours
while the undigested food sits in the large intestine it is broken down even more, explain what happens then
water is reabsorbed for the eliminaton of undigested food/waste products
how much of the body is water?
60 - 70%
water is by far the most important nutrient in the body, give an examples of its importance in relation to blood
as the base system for the blood it provides transportation system of the body.
what does water help to move to where it is needed
and what does it take away ?
nutrients, oxegen, vitamins and minerals
takes away waste products to the excretary organs
water plays a vital role in temperature regulation
it distributes heat allowing the body to ? check this one out in manual, heat to exercising muscles and to cooler places like the skins surface
water is the environment in which
EXPLAIN
every single chemical reaction that occurs in the body takes place
