Lungs 1 Flashcards
Which lung is bigger?
right - left is smaller d/t heart
What are the 2 linings of the lungs?
visceral pleura outside lungs
parietal pleura inside thorax
visceral means _____
organ
The area between the pleura of the lungs is called
potential space - has mucous to reduce friction
Differentiate between inspiration and expiration and movement of the lungs/diaphragm
Inspiration - diaphragm contracts and pulls down with lungs
Expiration - diaphragm relaxes and goes up with lungs
The diaphragm is anchored in the _____ spine
lumbar
What are the openings of the diaphragm?
caval aperture - vena cava
esophageal aperture - esophagus
aortic aperture - aorta
What is the central tendon? Why is it different?
tendon in the middle of the diaphragm that connects muscle to muscle instead of normal muscle to bone; what the heart sits on
What nerves innervate the diaphragm?
Phrenic nerves - 1 for each leaflet of diaphragm
What are the accessory muscles used for ventilation?
Scalene muscles that anchor into top of skull and base of neck, providing a platform to prevent ribcage from being pulled up/down with diaphragm
- also have intercostal and abdominal muscles
When performing regional anesthesia to brachial plexus, what nerve is present in the area that anesthetics can leak into?
phrenic nerve
How many phrenic nerves do you need to stay alive
1!
How many generations of airways are there in the respiratory system?
24
The trachea is generation ___
0
What parts of the airway are located in the conducting zone?
trachea, bronchi, bronchioles, and terminal bronchioles
What parts of the airway are located in the respiratory zone?
respiratory bronchioles, alveoli (ducts and sacs)
How are respiratory bronchioles different from terminal bronchioles?
respiratory bronchioles have a few alveoli that allow for some gas exchange to occur
What is the normal diameter of the trachea?
2 cm
Which part of the airways have cartilage?
conducting zone
alveoli have soft tissue only
Cyanosis occurs when deoxyhemoglobin > _____
5 gm/dL
What is the functional unit of the lung?
alveoli
1 mmHg of pressure = _____ cmH2O
1.36
Why are the units for pressure different in the lungs vs CV system?
switch units bc thoracic pressures are lower → greater resolution bc water is less dense than mercury
- cmH2O for pressures inside chest
- mmHg for CV and gas pressures
Define content in terms of the pulmonary system
blood gases (O2 content of blood 20 mL O2 in 1 dL of arterial blood)
Differentiate between a, A, v, V pulmonary abbreviations
- Alveolar (A)
- Arterial (a)
- Venous (v)
- Ventilation (V)
Define capacity in terms of the pulmonary system
combined individual volumes
What is the inverse of compliance?
Elastance
Is it easier to measure air coming out or going in a patient?
Coming out
Total lung capacity is ____ and includes?
6 L
inspiratory capacity (3 L) and functional residual capacity (3 L)
Inspiratory capacity consists of?
Inspiratory reserve volume (IRV) - 2.5 L
Tidal volume (VT) 0.5 L
Functional residual capacity consists of?
Expiratory reserve volume (ERV) - 1.5 L
Residual volume (RV) - 1.5 L
What is the maximal expiration?
IC + ERV = 4.5 L
(1.5 L left - RV)
What is the resting volume of the lungs?
3 L
What is the maximal inspiration?
FRC + IC = TLC or 6 L
What is vital capacity?
4.5 L
VC = ERV + VT + IRV
What is the “working volume” of the lungs?
vital capacity
How long is a normal respiratory cycle?
5 sec - inspiration (2 sec) + expiration (2 sec) + hold for 1 sec
What is the normal RR?
12 bpm
What is the pleural pressure at the end of inspiration and expiration?
-5 cmH2O in between breaths/end of expiration
-7.5 cmH2O at the end of inspiration
When is alveolar pressure (PA) the lowest? Highest?
- lowest at 1 sec into inspiration, -1 cmH2O
- highest at 1 sec into expiration, 1 cmH2O
What allows for expiration when the diaphragm relaxes?
Elastic recoil
What is the air flow rate?
avg 500 mL/ 2 seconds
inspired air flow rate is negative, expired air flow rate is positive
starts slow and peaks at 1 sec (half way) at 0.5 L/s
What is transpulmonary (transmural) pressure (PTP)?
difference in pressures on two sides of the wall (pleural vs alveolar pressures); pressure used to bring air into lungs
What are the 4 West Perfusion Zones?
- Upper lung: always off
- Middle lung: in-between
- Lower lung: always on
- Really lower lung: less always on (weight of lung - compression)
PA, Pa, and Pv for each zone?
- PA>Pa>Pv
- Pa > PA > Pv
- Pa>Pv>PA
Which perfusion zone is only present in unhealthy people or pt on PPV?
zone 1
The conducting zones of airway consist of
trachea, bronchi, bronchioles, terminal bronchioles
The transitional zone of airway consists of
respiratory bronchioles
The respiratory zone of airway consists of
respiratory bronchioles*, alveolar ducts, alveolar sacs
Which generation are the bronchi?
1-3
respiratory bronchioles begin at what generation
17-19
alveolar ducts begin at what generation
20-22
alveolar sacs begin at what generation?
23
Which region of the airways has the highest cross sectional area?
alveolar sacs, 10^4 cm2
hypoxemia refers to
low amount of O2 in the arterial blood
hypoxia
