P1+P2 - 2g gas exchange Flashcards
how does the act of Inhalation work?
- air pressure drops and air goes in, the pressure inside the body goes below the atmospheric pressure and air will go in the lungs to equalise it.
what happens when you are breathing out?
it decreases the space in the body (lungs, ribs, muscles) so air goes out
how does the pressure drop in the body?
external intercostal muscles pull the rib cage up and out, at the same time the diaphragm contracts and goes down
- the volume increases in the thorax and therefore the pressure decreases
what happens in exhalation?
the opposite happens in inhalation the internal intercostal muscles aren’t used, in exhalation because gravity is normally enough for normal breathes
- the volume decreases and the pressure increases
- diaphragm goes up
what is ventilation?
breathing in and out
what are the alveolus?
where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out
what are the adaptations of alveolus?
good blood supply
high surface area
very thin and compacted
tube gets folded to increase surface area
how thick are the alveoli?
one cell thick to allow for diffusion
why do the alveoli have good blood flow?
maintains a concentration gradient, it takes away the oxygen so it can keep going
what is the pleural membrane?
is a thin membrane around the lungs that contains the pleural liquid in it
what does the pleural liquid do?
protects the lungs from damage and acts as a lubricant
what are the effects of smoking?
- contains many chemicals
- tar builds up inside the alveoli
- takes away surface area
- causes emphysema
- lungs
what is emphysema?
loss of alveoli
- takes away surface area and destroys alveoli
what is epiglottis?
is the flap that stops the food from going down the trachea
what is the role of diffusion in gas exchange?
it is the process by which gas exchange occurs, it can happen through the cell membrane
what is the bronchi or bronchus?
the tube thing that connects the lungs to the trachea
what is the trachea?
where oxygen travels to the lungs
how do you spell dia…?
diaphragm
how is the leaf structure adapted to carry out photosynthesis and gas exchange?
the palisade and spongy mesophyll layers are arranged in a specific way
what is carbon dioxide used in and when is it released?
released in respiration and used in photosynthesis
what is oxygen used in and when is it released?
released in photosynthesis and used in respiration
when is water vapour released?
respiration and transpiration
pathways of CO2 in plants?
atmosphere - air spaces around spongy mesophyll - leaf mesophyll cells - chloroplasts
what are adaptions to to whole leaf for gas exchange?
- thin so short diffusion distance
- large surface area to volume
- stomata maintaining steep concentration gradient
- air spaces
- moist air inside leaf
when do the stomata close?
when the guard cells are flaccid (lack water)
when do the stomata open?
when the guard cells are turgid (too much water, swell)
what is the aerobic respiration equation?
glucose + oxygen -> carbon dioxide + water
co2 moves out of the leaf
o2 moves in by diffusion
what do plants do at night?
only respire
what is the practical to investigate the effect of light on net gas exchange from a leaf using hydro-carbonate Indicator?
tube A- no leaf, control, with 20 cm3 of indicator, stays yellow, nothing happens
tube B - leaf in sun, // turns purple from CO2
tube C - leaf wrapped in foil, //, yellow, release of CO2
tube D - leaf wrapped in gauze, //, stays orange, levels remain the same
