Exchange surfaces-basics Flashcards
definition of tissue
part of an organ made up of the same type of cells, doing the same function (muscular tissue contracts)
definition of an organ
A part of a living thing that plays a particular role (heart pumps blood around the body)
definition of an organ system
a group of organs that work together to do a particular job (digestive system)
how do you work out the surface area of a rectangular prism?
2(lw+lh+wh)
how do you work out the surface area of a sphere?
4πr²
how do you work out the volume of a rectangular prism?
lwh
how do you work out the volume of a sphere?
(4/3)πr³
how do you work out the surface area of a cylinder?
2πr²+πdl
why do exchange surfaces have a large surface area?
Larger area for exchange to occur
why are exchange surfaces thin?
so there is a shorter diffusion pathway
why do exchange surfaces have a good blood supply?
to remove products - carry to other places in the organism
why are exchange surfaces moist?
so gases can dissolve and diffuse
why do exchange surfaces have movement? e.g. blood flowing past the surface
to maintain a steep concentration gradient
why do multicellular organisms need a specialised exchange surface?
- small surface area to volume ratio
- very metabolically active
- require lots of O2 for aerobic respiration
- diffusion would be too slow to keep up with demand
- the diffusion pathway would be too long
what is the function of cartilage?
provides support and stops the trachea and bronchi from collapsing when the pressure drops
what is the function of smooth muscle?
controls diameter. during exercise, it relaxes so it’s wider so more air can move on. contracts to constrict
what is the function of elastic fibres?
aids breathing out, they stretch when breathing in then recoil forcing the air out
what is the function of goblet cells?
secretes mucus, traps dust and microorganisms/stops them reaching the alveoli
what is the function of ciliated cells?
moves mucus upwards, away from alveoli and towards the throat where it is swallowed, preventing lung infection
where is cartilage found?
- trachea
- bronchi
- large bronchioles
where is smooth muscle found?
- trachea
- bronchi
- large bronchioles
- small bronchioles
where are elastic fibres found?
- trachea
- bronchi
- large bronchioles
- small bronchioles
- alveoli
where are goblet cells found?
- trachea
- bronchi
- large bronchioles
where are ciliated cells found?
- trachea
- bronchi
- large bronchioles
- small bronchioles
