7.1 Exchange Surfaces / Human Ventilation Flashcards
what’s the process of inspiration
diaphragm contracts flattens and lowers
external intercostal muscle contract moving the ribs up and out
volume of thorax increases so pressure of thorax decreases
pressure in thorax is now lower than atmospheric pressure so air is drawn in through the wind pipe to the alveoli
is inspiration passive or energy using
it’s an energy using process
is expiration a passive or active process
passive but forced expiration is active
what’s the process of expiration
diaphragm relaxes and domes back up
external intercostal muscles relax so ribs move down and in under gravity
volume of thorax decreases so pressure increase
pressure in thorax is higher than atmospheric pressure so air moves out through the windpipe
what is the process of forced expiration
the internal intercostal muscles contract pulling the ribs down hard and fast
abdominal muscles contract and forces the diaphragm up to increase pressure in the lungs rapidly
why does the trachea contain cartilage and what shape is it
c - shaped and it prevents to trachea getting bent or squished
which parts of the mammalian gas exchange system contains cartilage
trachea
bronchus
large bronchioles
what type of epithelium cells does each part of the mammalian gas exchange system have
trachea - ciliated
bronchus - ciliated
bronchioles - squamous
alveoli- squamous
what does the smooth muscle in the bronchioles do
controls how much air enters the bronchioles as they can contract and relax
which parts of the mammalian gas exchange system contains goblet cells
trachea and bronchus
what does ciliated epithelium do
move mucus produced by goblet cells up to the throat to be swallowed to prevent lung infections
what do goblet cells do
produce mucus to trap the bacteria and dust that’s inhaled
what do the elastic fibres in the alveoli do
they allow the alveoli to stretch as they take in air and they push air back out as they return to their normal size
how are alveoli adapted for gas exchange
- loads of them and they are very small so large surface area
- squamous epithelium cell very thin so short diffusion distance
- elastic fibres allow them to expand to take in more air
- surrounded by a network of capillaries so good blood supply to maintain concentration gradient
what are good features of a specialised exchange surface
- increased surface area
- thin layers
- good blood supply
- ventilation to maintain diffusion gradient
