Mechanisms Of Breathing Flashcards
How do antagonistic pairs work
As one muscles contracts the other relaxes
What are the ribs connected by? How do these work?
2 layers of intercostal muscles
They work antagonistically
What type of process is breathing in? What does this mean
Active process
This means it uses energy
What type of process is breathing out
Passive
What happens during the process of breathing in
External intercostal muscles contract, internal intercostal muscles relax.
Ribs are pulled upwards and outwards, the diaphragm muscle contracts (flattens). This increases the volume of the thorax.
There is then less pressure in the lungs compared to the atmospheric pressure, so air is forced in to the lungs.
What happens during the process of breathing out
External intercostal muscles relax, internal intercostal muscles contract.
Ribs are pulled downwards and inwards, the diaphragm muscle relaxes. This decreases the volume of the thorax.
There is then more pressure in the lungs compared to the atmospheric pressure, so air is forced out of the lungs.
What happens to the intercostal muscles when breathing in
External intercostal muscles contract, internal intercostal muscles relax
What happens to the intercostal muscles when breathing out
External intercostal muscles relax, internal intercostal muscles contract
What happens to the ribs and diaphragm when breathing in
Ribs are pulled upwards and outwards, the diaphragm muscle contracts (flattens). This increases the volume of the thorax
What happens to the ribs and diaphragm when breathing out
Ribs are pulled downwards and inwards, the diaphragm muscle relaxes. This decreases the volume of the thorax
Define pulmonary ventilation
The total volume of air that is moved into the lungs during one minute
Define tidal volume
The volume of air normally taken in at each breath, when the body is at rest
Define ventilation (breathing) rate
The number of breaths taken in one minute
What is the normal ventilation rate for a healthy adult
12-20 breaths per minute
What is the equation for pulmonary ventilation
Pulmonary ventilation = tidal volume x ventilation rate
