Breathing Flashcards
what happens to the diaphragm muscle when you exhale?
it relaxes, moves up and becomes dome shaped.
what happens to the diaphragm muscle when you inhale?
it contracts, moves down and flattens
what is ventilation?
the process of moving air in and out of the lungs.
how do you test for carbon dioxide, using limewater?
- breathe through a straw into limewater.
2. if it goes cloudy carbon dioxide is present
how do you test for carbon dioxide, using bicarbonate indicator?
- crush germinating peas and put them in a test tube - this causes the peas to release the CO2 in their cells.
- then set up the experiment - 2 test tubes with a tube connecting them, on with the peas and one with the bicarbonate indicator.
- if the bicarbonate indicator changes from red to yellow. CO2 is present.
how do you measure heat energy produced by respiration?
put germinating peas in a conical flask and secure a thermometer in there with cotton wool - make sure no air can escape. Then read the thermometer at regular intervals.
what is the percentage of carbon dioxide in inhaled air?
0.04%
what is the percentage of carbon dioxide in exhaled air?
4%
what is the percentage of oxygen in inhaled air?
21%
what is the percentage of oxygen in exhaled air?
16%
what is underneath the lungs?
a sheet of muscle called the diaphragm
what are the lungs protected by?
the ribcage
where are the lungs located?
inside the thorax (chest)
what does breathing do?
- gets air in and out of the lungs
- gets oxygen from the air into the blood
- gets carbon dioxide from the blood into the air
what is the percentage of water vapour in inhaled air?
variable
what is the percentage of water vapour in exhaled air?
always high
what is the percentage of nitrogen in inhaled air?
78%
what is the percentage of nitrogen in exhaled air?
78%
how do ciliated cells keep lungs clean?
they have tiny cells that wave and move the mucus upwards and out of the lungs.
how do goblet cells keep the lungs clean?
they make mucus which traps dust and bacteria
what takes place in the alveoli?
gas exchange
what things are in the structure of the thorax?
trachea ribs intercostal muscle bronchiole bronchus diaphragm pleural membrane alveoli lungs pleural cavity
what happens to the ribs when you inhale?
they move upwards and outwards.
why are alveoli folded?
it gives a large surface area
why are the walls of the alveoli only one cell thick?
there is a short distance so diffusion is fast
why is the lining of the alveolus moist?
gases can dissolve which speeds up diffusion?
what is each alveolus surrounded by and why?
blood capillaries to transport oxygen
how many alveoli are there in each lung?
millions - there is a large surface area for gas exchange
what happens to the intercostal muscles when you inhale?
they contract
what happens to the pressure in the lungs when you inhale?
it decreases
what happens to the intercostal muscles when you inhale?
they relax
what is emphysema?
the alveoli gets a thicker wall which means diffusion takes longer - it also reduces surface area.
what happens during gas exchange in the alveoli?
CO2 diffuses out and O2 diffuses in
what does COPD do?
narrows the airways and destroys lung tissue
what happens to the ribs when you exhale?
they move downwards and inwards
what does smoking do to the alveoli?
damages the walls
what happens to the pressure in the lungs when you exhale?
it increases
what happens to the volume of the thorax when you exhale?
it decreases
what happens to the volume of the thorax when you inhale?
it increases
how is smoking cough caused?
harmful chemicals damage the cilia which leads to a build up of mucus which causes smoking cough
