Ventilatory system Flashcards
What is the carina?
- bifurcation of primary bronchi
- produce cough reflex
What are the three branches of the bronchi and what do they supply?
- primary: supply lungs
- Secondary: supply lobes
- Tertiary: supply lobules
What are the inspiratory muscles?
- diaphragm
- ext. intercostal muscles
- sternomastoids
- serratus anterior
- scalene
What are the expiratory muscle?
- abdominal and internal costals produce forceful expiration.
- generally passive at rest.
What are the branchings of the bronchioles?
- terminal and respiratory
- with smooth muscle but no cartilage
At what point in the respiratory tract do we begin to gain control of the amount of air we can take in?
The area of where we start to gain control of how much air is being passed for respiration.
Define total lung capacity.
-maximum volume of gas the lungs can hold
What helps to form the total lung capacity?
-non overlapping compartments form lung volumes
Tidal volume is what and what volume?
500mL
volume inspired and expired with breathing
Inspiratory reserve volume?
- 3000mL
- amount of air that can be inspired in addition to tidal volume
- requires forced inspiration to do so
Expiratory reserve volume?
- 1100mL
- amount of air expired at end of tidal volume by forced expiration
Residual volume?
1200mL
-amount of air remaining in the pulmonary system after forced expiration
Vital capacity?
4600mL
- sum of all air inspired/expired
- max inspiration to max expiration
Total lung capacity
sum of all volumes.
- includes vital capacity + residual volume
Inspiratory capacity?
sum of volume above resting capacity
-therefore is tidal volume + inspiratory reserve volume
Functional residual capacity
-expiratory reserve volume + residual volume
the sum of volume below resting capacity
Describe minute volume and the equation to describe it.
- volume of gases moved in or out of lungs per minute
- V= breath per minute * tidal volume
What is alveolar ventilation and the equation to describe it?
- volume of gases that enter spaces participating in gas exchange per minute
- (bpm)*(TV-DS)
What is anatomic dead space?
-the space where air remains in the trachea, bronchi, bronchioles
What is physiological dead space?
-anatomic dead space+ventilated alveoli with poor perfusion
What is pleural pressure?
-fluid between parietal and visceral pleura
What is alveolar pressure?
-pressure inside the alveoli
The transpulmonary pressure?
-difference between the alveolar pressure and the pleural pressure
Total tidal volume is 0.5L so what is the amount of respirated and perfused alveoli in normal individual with dead space of .15L?
-0.35L
The amount of CO2 in the arterial blood will be equal to what?
arterial CO2 level equals the amount of CO2 in the lungs
How can we verify that dead space is the eqaution that is used?
- dead space air does not participate in exchange and has negligible CO2
- blood gases equilibrate during gas exchange in capillaries, therefore blood CO2 equals the CO2 in region of the lungs
What happens to the pressure in the alveoli during inspiration/ expiration?
- inspiration: decrease of pressure
- expiration: increase of pressure
What is the compliance of the lungs?
-the extent to which lungs will expand for each unit incrase in transpulmonary pressure
Compliance is a measure of what?
-the expansibility of the lungs and the trachea
What is a major component that allows the lungs to function normally in air, and not at all in water?
Saline helps to reduce the amount of surface tension that opposes the movement of the lungs
What component is similar to saline in the lungs that reduce surface tension and improve the ventilatory efficiency?
-surfactant
Surfactant contains what three components secreted by what cells?
- dipalmitoylphosphatidylcholine
- surfactact apoproteins
- Ca ions
- produced by type II alveolar cells.
What is the equation for surface tension on the pressure?
pressure= 2* surface tension/ alveolar radius
By how much does surfactant reduce the surface tension in the lungs?
-reduces by 4.5 times.
What cells, muscles and cartilage are in the trachea?
- pseudostratified ciliated columnar with goblet cells
- cartilaginous rings
- trachealis muscle