L5 - Respiration II - Ventilation & Perfusion Flashcards
What is ventilation?
The volume of air moved out of the lungs per unit of time.
ventilation= volume / time
What is Alveolar ventilation?
The Volume of fresh air reaching the alveoli / respiratory zone
alveolar ventilation = total ventilation - anatomical deadspace.
What is anatomical deadspace?
Volume of air located in the respiratory tract that are conduct air to the alveoli and respiratory bronchioles but do not take part in the process of gas exchange itself.
What does ventilation rate have an impact on?
Alveolar and arterial gas compostion
What happens during hyperventilation?
The same amounts of CO2 are made at rest, it just comes out at a greater volume leading to respiratory alkalosis.
Partial pressure of oxygen in the alveoli during hyperventilation is similar to atmospheric pressure.
Where is ventialtion greater in the lungs?
At the base
The Apex has a …
Larger starting volume and lower compliance
The Base has a …
A smaller starting volume and higher compliance
Pulmonary cirulaton is a …
Low pressure / Low resistance system.
Not long to travel, from the heart to the lung rather than from the heart to the rest of the body.
When is pulmunary resitance at its lowest?
When the lungs are at functional residual capacity
What is resistance linked to?
Transmural pressure and lung volume.
What does lung perfusion depend on?
Posture and gravity
What are some factors that alter perfusion?
Dilators and Constrictors
Dilators
Bradykinin
Theophyline
Acetylcholine
B- adrenergic agonists
Constrictors
Serotonin
Angiotensin II
a- adrenergic agonists
