Digestive System Flashcards
What is our buccal cavity
Our mouth (oral cavity)
What do we use to make our food small enough to swallow
Our jaws
Where are the salivary glands loacted
Under the tongue and in the cheeks
What is the point of saliva
Helps moisten food and make it easier to swallow
The food slides past the epiglottis and enters what
The oesophagus or gullet
What is the process of food being squeezed by the muscles in the oesophagus
Peristalsis
What is the stomach
A muscular sack that churns our food around and starts to chemically alter the protein in our diet
After leaving the stomach, where does food (chyme) go next
The small intestine
What is the first part of the small intestine called
Duodenum
What happens in the duodenum
There is further chemical alteration that takes place aided by fluids provided by the liver and pancreas
What makes bile
The liver
What stores bile
The gallbladder
How does bile leave the gallbladder to get to the gut
Down the bile duct
What does the pancreatic duct carry
A fluid containing digestive enzymes and alkaline salts
Where do the altered nutrients leaving the duodenum go to
The ileum
What is the ileum covered in
Villi
What are villi
Finger-like projections containing blood vessels, like a thick carpet
What picks up nutrients after the ileum
The blood
Where does the substances that are unable to break down kept
The gut
Where do the substances that cannot break down chemically move to
The large intestine or colon (where much of the water is taken back into the blood)
What lives in the colon
Trillions of mostly beneficial bacteria
What does the bacteria in the colon feed off
Undigested food
What does the bacteria in the colon provide us with
Vital vitamins such as folic acid and vitamin K
Where does the dried out remains of our food and dead bacter that forms faeces get stored
The rectum
What is the rectum
A muscular tube that eventually expels the waste from the anus
What are the specialised proteins that chemically change nutrients into smaller, soluble units
Enzymes
Where does the most important form of mechanical digestion take place
The stomach
Muscles in the wall of the stomach churn our food around, what does this do
Makes it smaller
What does pulverised food provide our digestive enzymes with
Much easier access to nutrients
What are the three large chemical nutrients that are too big to pass through the wall of our gut into the blood and then be carried by it
Proteins, carbohydrates and fats
What carries out the action that turns large molecules into smaller ones for them to be digested
Enzymes
How do enzymes work
Breaking chemical bonds
An enzyme found in saliva (salivary amylase) breaks down starch into what
Maltose
An enzyme found in the stomach (pepsin) works in acidic conditions and breaks down proteins into what
Poypeptidess
Acidity in the stomach mean that chyme has a low pH and and this will prevent what
Any further chemical digestion due to other enzymes being denatured
Where does chyme enter when it becomes neutralised
The duodenum
What makes the gut contents slightly alkaline
Alkaline salts
What supplies the gut with alkaline salts
Bile from the liver and the pancreatic juice from the pancreas
The pancreas and the walls of the duodenum also supply further digestive enzymes that bring about the necessary changes to what
Carbohydrates, proteins, fats as well as to the DNA that makes up the genes and chromosomes found in the cells of the food we eat
What is a problem for successful chemical digestion
The presence of water in the gut
Why is water in the gut a problem
Fats and water don’t mix
When does the gallbladder release bile
When fats are eaten
What do villi of the ileum wall increase so that as many nutrients as possible are absorbed
Surface area
What does each villus contain
Blood capillaries and a lacteal - which is connected to the lymph system
sugars, amino acids, minerals and water soluble vitamins (B and C) enter the blood by what
Diffusion
Fatty acids and glycerol recombine as fats once absorbed by what
The villus, and they pass into the lacteal together with fat-soluble vitamins
When the products of digestion enter the blood they are not taken off around via the heart, how does it travel instead
Along the hepatic portal vein (that carries them to the liver)
How many functions does the liver carry out
Over 500
What is one of he functions of the liver
Act as a storage/distribution centre
The liver stores excess glucose as a carbohydrate called
Glycogen
The liver distributes the nutrients to where
Cells (when they’re required)
The role of the liver in sorting, utilising and distributing necessary metabolic chemicals is known as what
Assimilation
