ventilation mechanisms in mammals Flashcards
(23 cards)
What is ventilation?
The method by which air is passed over the respiratory surface to ensure a high concentration gradient is maintained.
What is inspiration?
Breathing in.
Is inspiration active or passive?
Active.
How do the external and internal intercostal muscles work?
Antagonistically.
Which muscles contract during inspiration?
External intercostal muscles, diaphragm.
Which muscles relax during inspiration?
Internal intercostal muscles.
What does the diaphragm do during inspiration?
It contracts which causes it to flatten.
How does all this cause inspiration?
All these actions increase the volume of the thoracic cavity.
What happens to the pressure during inspiration?
The pressure inside the lungs decreases below atmospheric pressure and air enters down a pressure gradient.
What is expiration?
Breathing out.
Is expiration active or passive?
Passive.
Which muscles relax during expiration?
External intercostal muscles, diaphragm.
Which muscles may contract to pull the ribcage downwards and inwards?
The internal intercostal muscles.
What does the diaphragm do during expiration?
It relaxes and moves upwards to its dome shape.
What do these actions do?
They decrease the volume of the thoracic cavity.
What happens to the pressure in the lungs in expiration?
It increases above atmospheric pressure and air is forced out the lungs.
What can also help to force air out of the lungs?
Elastic recoil of the lung tissue.
What is pulmonary ventilation?
The total volume of air that is moved into the lungs in one minute.
What is needed to calculate the pulmonary ventilation?
Tidal volume and ventilation rate.
What is tidal volume?
The volume of air taken in at each breath.
What is ventilation rate?
The number of breaths per minute.
What is the equation to calculate pulmonary ventilation?
Pulmonary ventilation = tidal volume x ventilation rate.
What can increase the strength of the intercostal muscles?
Training.
