The Digestive System Flashcards
absorbtion
passing of useful components of food from the GI tract into the blood
autotroph
living organism that has the ability to make its own food
balanced diet
correct amount of each group from the food pyramid
chemical digestion
use of enzymes to breakdown food
diffusion
movement of molecules from an area of high molecule concentration to an area of low molecule concentration- passive process
digestion
breaking food down into smaller parts by physical and chemical digestion
egestion
removal of unabsorbed waste material from the GI tract
emulsification
clumping together of triglycerides
emzyme
biological catalyst made up of protein
excretion
removal of wate products of metabolism from a living organism
hetetroph
living organism that cannot make its own food
Ingestion
taking in of food
mechanical digestion
physical breakdown of food
metabolism
sum of all chemical reactions in a living organism
optimum ph
ph at which an enzyme works best
osmosis
movement of water molecules from an area of high concentration to an area of low water concentration across a selectivity permable membrane
peristalsis
muscular contraction of muscle walls of alimentary canal
physical digestion
mechnical breakdown of food
a portal system
a system that begins and ends in capillaries
symbiosis
two organism of different species living together involving benefit.
what is nutrition
how an animal gets its food
Name the stages of human nutrition
Ingestion
digestion
absorbtion
Egestion
What is Ingestion and where does it occour
Taking in food,occurs in mouth
what is digestion and where does it occour
breaking food into smaller parts by physical and chemical means, occours in oesphagus and stomach
what is absorption and where does it occour
passing of useful components of food from the GI tract into blood. occours illium - SI by diffusion.
Colon by osmosis
what is egestion and where does it occour
Removal of undigested food
from the human alimentary
canal
Large intestine- rectum and
anus
why is digestion important
it breaks down food so that its small enough to be absorbed into the blood and easier to transport to cells in the blood where it is required
name the two types of digestion
physical: mechanial breakdown of food
chemical: use of chemicals such as enzymes and acid to help breakdown food
The role the mouth plays in digestion
Take in of food and help break it down using teeth and amylase
describe the dental formula
( I 2/2 C 1/1 PM 2/2 M 3/3 )x2
Describe the physical digestion that occours in the mouth
teeth
describe the types of teeth
Incisors- flat for biting
Canines - sharping for tearing
Premolars + Molars - chewing
describe the role of the osephagus
moves food from mouth to stomach.
epiglottis closes over trachea.
food formed into a bolus (moist ball)
explain physical digestion in the osephagus
peristalsis - muscular contraction of the alimentery canal. moves content along
mucus- moistens food
what aids peristalsis
fibre
State the role of the stomach in digestion
muscular bag that holdes and digests food.
Kills pathogens in the stomach
HCl PH2
state the role of physical digestion in the stomach
Churning
state the role of chemical digestion in the stomach
HCl kills microrgamisms at ph 2, activates pepsin by providing an acidic environment
Pepsin enzyme that breaks down proteins into AA
stomach lipase turns lipids to fatty acids and glycerol
explain the role of the stomach lining
prevents stomach corrosion by HCL
prevents digestion of stomach muscle wall by pepsin (muscle is a protein that can be broken down mby pepsin)
Explain both the endocrine and excocrine role of the pancreas
endocrine (Isle of langerhans) Produces Insulin.
excocrine - pacreatic amylase
pancreatic lipase
what happens to products of panereas
Products of pancreas
transported to duodenum via
pancreatic duct.
List the functions of the liver
Produces Bile, which neturalises chyme, emulisifes tryglicerides
temperture regulation- prevents enzyme denaturation
deamination- breakdown of excess amino acids into urea
stores vitamin K (required for clotting blood)
Describe the hepatic portal system
hepatic artery (right side) carries oxygenated blood from heart to liver.
hepatic vein carries co2 rich blood from liver to heart
Hepatic portal vein: carries blood containing vitamins and glycogen from SI to liver ( carries end products of digestion from small intestines to liver)
state the function of the Gall bladder
stores bile
How is bile transported in the gall bladder
bile transports to small intestine via bile duct
State the role of the duodenum
final stages of digestion ocoour by perisalsis and enzymes in the duodenium
chemical digestion that occours in the duodenum and the PH
Bile
pancreatic lipase - lipids to fatty acids and glycerol Ph 7-8
Pancreatic amylase starch to maltose ph 7-8
state the function of the illeum
absorbion of food ocoours in ileum
Describe chemical digestion that occours in ileum
pancreatic amylase - starch to maltose
Pancreatic lipase- Fatty acids to glycerol
descrive the function of villi
responsible for absorbtion of food from SI to blood
how villi is adapted to their role
exist in large numbers (large SA)
cell wall one cell thick for faster absorbtion
having a rich blood supply
list the structures in a villi
thin surface layer
capillaries
lacteal - connected to lymphatic system which aids absorbtion of fats
mucle wall
describe the function of the large intestines
water absorbed and waste removed
symbiotic bacteria present here
bacteria produce vit K and also create competition with harmful MO
State the section of the large intestines and their roles
caecum + appemdic - vestigual organs, no use
colon - absorb water to regulate consipation, forms semi solid feces, absorbs vitamins
rectum - stores undigested food waste material
anus - point of egestion
state the role of fibre in the digestive system
fibre cant be absrbed into blood
increases peristalsis and increases rate of waste removal( normalise bowel movement )
reduces risk of constipation
fibre is a source of food for symbiotic bacteria
end products of digestion
carbohydrates - monosaccrides ( glucose)
proteins- amino acids
lipids - glycerol + fatty acids
What is the ph of substances that enter the duodenum
Ph 1
Outline the fate of food that enters the small intestines
It is absorbed into the ileum or lacteal or carries in the blood stream towards the liver via the hepatic portal vein
Outline the fate of food that enters the small intestines
It is absorbed into the ileum or lacteal or carries in the blood stream towards the liver via the hepatic portal vein
