The Respiratory Cycle Flashcards
What N. Is the diaphragm innervated by
The phrenic N.
Define what happens in inspiration
Ribs move up and out (contraction of intercostal muscles)
V increases
P of Alv. And intrapleural space decreases
Air moves in
Define what happens in expiration
Ribs move down and in (relaxation, passive)
V decreases
P of Alv. And Intrapleural space increases
Air moves out
The respiratory muscles are what type of muscles
Skeletal
What is the main con for having skeletal muscle for resp. Muscles
Length-Tension Curve
If myofilamaents are too close or too far away, can over stretch lungs and add to dead space
What is intrapleural pressure at rest
-5 cmH20
During inspiration, what does intrapleural pressure decrease to
-8 cmH20
What is the alveolar pressure at rest
Same as external atmosphere (0cmH20)
During inspiration, what does alveolar pressure drop to
-1cmH20
When does intrapleural pressure reach its lowest point
At the end of inspiration
Air flow in the lungs will decrease when and at what point
Will decrease as alv. Pressure returns to 0 at the end of inspiration
What is the typical Vt
500 ml
When will alv. Pressure reach it’s peak
About +1cmH20 at mid expiration
Inrapleural pressure remains negative because why
No new air (molecules) added to it
What is the equation for minute ventilation
V(dot) = Vt x f
