Dr. Poole's Test Flashcards
What is the principle function of the lung?
- gas exchange (principle function)
- acid base regulation
- filter toxins
By what process do O2 and CO2 move between the air and blood within the lung?
diffusion (from higher to lower pressure)
Ficks law
Vgas= A/T x D (Pa- Pblood)
increased surface area
decreased thickness
CO2 is more diffusible
Change in pressure is more in favor of oxygen
What are the two zones of the lung and in which one does the most gas reside?
- conduction zone (airways that do not help with gas exchange) (150 ml)
- respiratory zone (alveoli) (2-5 L)
Respiratory zone takes up most of the volume of the lung (2-5 L)
How may airway bifurcations are found in the human lung?
23 bifurcations
First 16 in conducting zone
last 7 in the respiratory zone
Draw a graph depicting the relationship between airway generation and total airway cross sectional area
pg 5 lecture 1 and 2
What are the 3 cell types found in the alveoli an what are their functions?
- Type 1 (egg shaped) (90% of alveolar wall)
- Type 2 ( secretes surfactant lowering surface tension)
(these contribute to the high compliance and distensibility of the lung) - macrophages (engulf tiny particles too small to be filtered out upstream)
type 1 alveolar cells
egg shaped and make up 90% of the alveolar wall
type 2 alveolar cells
- secrete surfactant lowering the surface tension
- contributes to the high compliance and distensibility of the lung
macrophages
engulf tiny particles too small to be filtered out upstream
What are the two main forms of connective tissue found in the lungs?
collagen and elastin
ventilation at rest
7,500 ml/min or 7.5 L/min
tidal volume
500 ml or .5 L
respiratory frequency
15 breaths/min
alveolar gas volume
3,000 ml 3L
dead space volume
150 ml or .15 L
pulmonary capillary blood volume
70 ml
pulmonary blood flow
5000 ml/min
alveolar ventilation
5250 ml/min
functional residual capacity
volume of gas in the lung at expiratory level
total lung capacity
volume of gas in the lungs at the end of max inspiration
how much you can breathe in
residual volume
volume of gas in the lungs at the end of maximal expiration
left over air/gas
vital capacity
maximal volume that can be expired after maximal inspiration
(greatest volume of air that can be exhaled)
Explain why it is more efficient to breathe more deeply (increase tidal volume) than increase breathing frequency.
deeper breathing is more efficient
rapid shallow breathing wastes too much air in the dead space
Where in the lung does most of the inspired air go and why?
ventilation is much higher at the base of the lung due to gravity
- it is reduced when the subject lies down and reduced the vertical height of the lung
what is the only respiratory muscle active at rest?
diaphragm