DIGESTIVE SYSTEM Flashcards
What is digestion?
the process by which the body breaks down food into smaller molecules
Where does digestion take place?
In the alimentary canal - a long tube that runs from the mouth to the anus.
What is the alimentary canal made up of?
made up of the mouth, esophagus, stomach, small & large intestine, rectum & anus.
Where does digestion begin and end?
Digestion begins in the mouth
and ends in the small intestine
What extra organs are also apart of the digestive system
- these organs secrete digestive juices to help break down food.
- salivary glands, liver, gall bladder and pancreas
Mechanical/ Physical digestion
- Chewing by teeth to breakdown food into smaller pieces.
- Churning by the tongue and the stomach muscles to help break down food
What is chemical digestion?
- the use of enzymes to break down food:
- Carbohydrates to simple sugars
- Fats to fatty acids and glycerol
- Proteins to amino acids
Describe what happens when food enters the mouth
- When food enters the mouth (ingested) it is chewed and mixed with saliva
- saliva made by salivary glands moistens the food and makes it easy to swallow
- salivary amalyze (an enzyme) that is found in saliva begins to change starch (carbohydrates) into maltose.
What happens during the process of swallowing?
Tongue rolls food into a BOLUS which is easy to swallow, and pushed to the back of the mouth into the esophagus
What is in place to prevent a person from chocking?
food is prevented from going the wrong path by a flap of tissue in the throat called the epiglottis.
The epiglottis covers the opening of the wind pipe.
What is the function of the esophagous?
- a tube that connects the mouth to the stomach.
- Its function is to contract and relax to move the bolus from the mouth into the stomach
Define peristalsis?
a series of wave-like muscle contractions that move food along the digestive tract.
Which gastric juices does the stomach contain?
1. hydrochloric acid- a very strong acid that kills germs and allows the enzymes to work
2. Pepsin- digests protein by breaking it down into polypeptides.
3. Renin - found in the babies and helps break down mik proteins.
What does the muscular wall of the stomach do?
The musclar walls grind and mix food with gastric juice producing a semi fluid mass of undigested food ** chyme .**
End Product of Bile salts
Emulsifies fats, split up liquid fats into fat droplets that can be easily digested.
End Product of Lipase
fat into fatty acids and glycerol
End Product of Trypsin
polypeptides into amino acid
End Product of Amylase
Starch or carbohydrates into maltose
End Product of Maltase
Maltose into glucose
End Product of Sucrase
Sucrose into glucose and frutose
End Product of Lactase
Lactose into glucose and galactose
Define Absorption?
- is the movement of nutrients through the wall of the small intestine into the bloodstream
What is the villi (singular villus)
they are tiny finger-like projections of tissue in the small intestine that increases the surface area for absorption.
This means that more nutrienrts are being absorbedand released into the blood to be used by cells
What is assimilation?
is the movment of digested food molecules into cells in the body where they are used
Where is fat absorbed
In the lacteal of the villi
What passes through the villus into the capillaries and is carried away in the blood stream to the hepatic portal vein which takes it to the liver
Glucose, amino acids, vitamins and minerals.
What happens when undigested food enters the large intestine
when undigested food enters the large intestine it becomes waste (fibre, dead cells,bacteria and water).
in the large intestine all nutrients are removed through the process of absorption
Where are feces stored?
In the rectum, and will pass ot the body through the anus
Define egestion
the process of passing undigested food or faeces through the anus
What does the salivary gland secrete
the salivary glands are found in the mouth which produce saliva to lubricate the mouth and moisten food and aid in swallowing.
- saliva contains an enzyme called salivary amalyse which breaks down starch into maltose.
What does the pancreas secrete?
it produces pancreatic juice which contains enzymes that it placed into the small intestine and helps break down food after it leaves the stomach
Where is bile stored?
Bile is stored in an organ called the gall bladder
What is the largest internal organ
The liver ( dark red or brown in color )
What are the functions of the liver?
- produces bile (green-yellow lquid)- that breaks down fat
- Produces blood protein that helps with clotting.
- produces urea ( toxic substance made when ptotein is broken down)
- Breaks down harmful substances like alcohol
- stores excess glucose as glycogen
- stores Vitamins A,B,D and mineral iron
