Digestive system Flashcards
What is absorption
Oxygen and nutrients from food must be absorbed into the bloodstream to be delivered to cells
Waste materials, such as carbon dioxide, must be removed from cells into the bloodstream.
What should be absorbed and removed from the bloodstream
Absorbed- oxygen & nutrients from food
Removed - carbon dioxide
What do capillaries in the tissue provide
They provide every cell access to blood
Surfaces involved in the absorption of materials all have:
- large surface area
- thin walls
- extensive blood supple
What are the mouth and nose connected to
The trachea
What does the trachea divide into once reached lungs
Two bronchi , both going into each lungs
What do each bronchus split into
They both split into smaller and more tubes called bronchioles
What do the bronchioles end with
They end in tiny air sacs called aveoli
Where does gas exchange occur
It occurs within the aveoli at the end of the bronchioles
Waht is gas exchange
It’s when Oxygen diffuses from the alveoli into the blood. Carbon dioxide
diffuses from the blood into the alveoli
Where does gas exchange exactly happen
The gas exchange happens between the alveoli and their surrounding capillary blood vessels
How is the alveoli efficient when it comes to absorption
- thin lining , gas can quickly diffuse through it
- large surface area, which speeds up diffusion as gases have more area needing to diffuse
-good blood supply, allowing large volumes of gas to be exchanged
What is digestion
Digestion is the breakdown of large insoluble molecules in our food into smaller soluble molecules, which can then be absorbed into the blood
(A special type of protein called an enzyme catalyses this breakdown.)
What part do enzymes play in digestion
Enzymes in the mouth, stomach and small intestines catalyse the breakdown of food from large substrates into small products
What order does enzymes work
Substrate - enzyme - product
