Part II Flashcards
Eupnea
Normal breathing
What is the normal arterial CO2?
40mmHg
How many breaths per minute is normal?
12-17 breaths per minute
Hyperpnea
Increased pulmonary ventilation matching metabolic demand
What is the arterial CO2 for hyperpnea?
40mmHg
Hyperventilation
Increased pulmonary ventilation, decreased metabolic demand
What is the arterial CO2 for hyperventilation?
Arterial CO2
Hypoventilation
Decrease pulmonary ventilation, normal metabolic demand
What is the arterial CO2 for hypoventilation?
Arterial CO2 > pulmonary ventilation
Apnea
Absence of breathing
Dyspnea
Difficulty breathing
Orthopnea
Difficulty breathing when recumbent
Who gets orthopnea?
People with congestI’ve heart failure, asthmatics, lungs failure patients
Tachypnea
Increased frequency of breathing
Is tachypnea good or bad?
Depends, could be because of exercise or hyperventilation
Do lungs have a natural tendency to collapse?
Yes
What prevents the lung from collapsing?
Surface tension forces (2/3) and elastic fibers (1/3)
What happens when the pleural space comes in to contact with the atmosphere?
The pleural pressure equals the atmospheric pressure and the lung collapses
What is a collapse lunget caused by?
Puncture wound
Erosion of visceral pleura
Blockage of major airway
Why would a blockage of a lunch get cause collapse?
The air distal to the block will be absorbed by the blood
What is pleural fluid?
Thin layer of mucous that provides lubrication
What kind of fluid is pleural fluid?
Transudate
What is the total amount of pleural fluid in the lung?
A few mL
How is excess pleural fluid removed?
Lymphatics in mediastinum, superior surface of diaphragm, lateral surfaces of parietal pleural
What helps make negative pleural pressure?
Pleural fluid
What is the purpose of surfactant?
Reduces surface tension forces by forming a monomolecular layer between aqueous fluid lining the alveoli and air, preventing water-air interference
What is surfactant produced by?
Type 2 alveolar epithelial cells
What is surfactant made of?
Phospholipids, proteins, dipalmitoyl lecithen, surfactant apoproteins, calcuim
Why is surfactant important?
Without surfactant, smaller alveoli have increased collapsing pressure and tends to empty into larger alveoli
What is the law of Laplace?
P= 2T/r
As alveolar size decreases, surfactant is concentrated which decreases surface tension forces, offsetting the decrease in radius
…
What is interdependance?
Size of one alveoli determined in part by surrounding alveoli
What lung capacities cannot be determined by basic spirometry?
RV, TLC, FRC
What is the equation to find FRC? What does it mean?
FRC= ([Hei]/[Hef])Vi
Hei= initial concentration of the helium Hef= final concentration of the helium Vi= initial volume of air in the jar
How do you determine RV?
RV= FRC-ERV
How do you determine TLC?
TLC= RV+VC
What parts of the lung capacity decrease with restrictive lung conditions?
VC, IRV, IC
How do you determine minute respiratory volume?
Respiratory rate x total volume
How do you determine forced expiratory volume?
Forced expiratory volume/vital capacity
What are the pulmonary flow rates?
Minute respiratory volume, forced expiratory volume, peak expiratory flow, max very tilatory volume
