Exchange and transport Flashcards
Why is diffusion fast in single celled organisms?
has to travel short distance
have high SA:V ratio
How does having a large surface area help root hair cells
-increases rate of absorption of water and mineral ions
How does being thin help the alveoli
There is a shorter diffusion pathway
How does having a good blood supply help the alveoli
- surrounded by dense capillary network
- which creates a steep concentration gradient
How does having a good blood supply help the gills
gills contain dense network of capillaries
also they are well ventilated due to water
-maintains steep concentration gradient
What is the structure of the gaseous exchange system
trachea splits into bronchi
bronchus leads to bronchioles
which leads to alveoli
What is the function of a goblet cell
- secretes mucus to trap microorganisams and dust particles
- stops them from reaching alveoli
What is the structure and function of cillia
structure
- made from microtuberoules 9+2
- have hair like structure
functions
-waft/beat the mucus up the air way towards the throat (helps prevent lung infections)
What is the structure and function of cartilage
-c shaped rings
function
- provide support
- stops trachea from collapsing
- rings provide flexablity
What is the function of smooth muscle
- allows diameter to be controlled (I think mark schemes like to say constrict)
- can make air tubes wider to decrease resistence to air flow
What is the function of elastic fibres
they streach and recoil when breathing in and out
prevent alveoli from bursting
where is cartilage found
trachea
small amounts on bronchi
Where is smooth muscle found
trachea, bronchi, broncheloles
but not in small broncheloles or the alveoli
Where are elastic fibres found
EVERYWHERE
Where are goblet cells
trachea, bronchi, large broncheoules
not found in smaller broncheoles, or the alveoli
Where are epithelium cells found
Cillaited
trachea, bronchi, large bronchi
squamous
alveoli
What happens during forced expiration
internal intercostal muscles contract, which pull ribcage down and in
What happens during inspiration
- intercoastal muscles and diagraphm contract
- causes ribcage to move upwards and outwards
- volume of throax increases so lung pressure decreases below atmospheric pressure
- so air comes into lungs
What happens during expiration
-intercostal muscles and diaphragm relax
-causes ribcage to move downwards and inwards
-volume of throax decreaes
-air pressure increses (above atmospheric pressure)
air is expelled from lungs
State the meaning of tidal volume
volume of air in each breath
usually 0.4 dm3
State the meaning of vital capacity
max volume of air that can be breathed in or out
State the meaning of breathing rate
how many breaths taken per minute (any unit of time really)
State the meaning of oxygen uptake
rate at which a person uses up oxygen
How do we use a spirometre
- breathe into a tube
- then a pen records the movement which is attached to the lid of the chamber
- this creates a spirometre trace
- can also use a data logger