4/17 Lecture E1 Flashcards
Approximate volume of the anatomic dead space
150 mL
What is the anatomic dead space?
Conducting zone of airway where there is no gas exchange.
What can alter (somewhat) the anatomic dead space?
Sympathetic and parasympathetic stimulation: sympathetic dilation increases dead space but allows greater flow
What is the total physiologic dead space?
= sum of anatomic dead space + pathological (from disease) alveolar dead space
What are the units of alveolar ventilation rate?
mL/min
What is the AVR equation?
AVR = Air that ventilates alveoli x respiratory rate
What is a spirometer?
a device that recaptures expired breath and records such variables as rate and depth of breathing, speed of expiration, and rate of oxygen consumption
What is Tidal Volume?
The volume of air inhaled and exhaled in one cycle of breathing (about 16 oz)
What is inspiratory volume?
The air in excess of tidal volume that can be inhaled with maximum effort (approx. 3000 mL)
What is Expiratory reserve volume:
Air in excess of tidal volume that can be exhaled with max effort (approx. 1200 mL)
What is residual volume?
The amount you cannot void, even after max exhalation (approx 1300 mL)
What is a benefit of residual volume?
Allows some gas exchange with blood before next breath of fresh air arrives.
What is the vital capacity equation?
VC = ERV + TV + IRV (4700 mL)
What is inspiratory capacity?
maximum amount of air that can be inhaled after a normal tidal expiration. IC = TV + IRV (3500 mL)
What is functional residual capacity?
the amount of air remaining in lungs after a normal tidal expiration. FRC = RV + ERV (2500 mL)
What is total lung capacity?
maximum amount of air the lungs can contain.
TLC = RV + VC (6000 mL)
What does spirometry help to diagnose?
restrictive and obstructive lung disorders
What are restrictive disorders?
Those that reduce pulmonary compliance or produce pulmonary fibrosis, such as black lung disease or tuberculosis.
Clinically, what are restrictive disorders seen as?
A decrease in VC
What causes Black lung disease?
particles cannot be removed, but macrophages continually attempt to engulf them, leading to chronic inflammation and fibrosis
What are obstructive disorders?
Those that interfere with airflow by narrowing or blocking the airway.
What do obstructive disorders cause?
difficulty inhaling or exhaling a given amount of air. Asthma, chronic bronchitis, emphysema (actually combines elements of restrictive and obstructive disorders)
What is bronchial Asthma caused by?
bronchospasms and bronchoconstriction
What are symptoms of bronchial asthma?
wheezing, coughing, tightness, shortness of breath, hard to inhale and exhale
RX for bronchial asthma?
bronchodilators (beta2- adrenergic agonists)
how is bronchial asthma diagnosed?
Low FEV1; microscopic Curschmann’s spirals in sputum (mucus plugs from ducts)
What is Forced Expiratory Volume?
percentage of the vital capacity that can be exhaled in a given time interval
What is a healthy adult FEV1 reading?
75% - 85% in 1 second
What is peak flow?
max speed of expiration, measured by blowing into a handheld spirometer
What is Eupnea?
Relaxed, quiet breathing
What is Eupnea characterized by?
Tidal volume of 500 mL and the respiratory rate of 12-15 bpm
What is Apnea?
temporary cessation of breathing
What is dyspnea?
labored, gasping breathing; shortness of breath
What is hyperpnea?
increased rate and depth of breathing in response to exercise, pain, or other conditions
What is hyperventilation?
increased pulmonary ventilation in excess of metabolic demand
What is hypoventilation?
reduced pulmonary ventilation leading to an increase in blood CO2 (= increased carbonic acid, decreased pH)
What is Kussmaul respiration?
deep, rapid breathing often induced by acidosis (rare and severe)
What is orthopnea?
dyspnea that occurs when person is lying down
What is respiratory arrest?
permanent cessation of breathing
What is tachypnea?
accelerated respiration
what is the composition of air?
78.6% nitrogen
20.9% oxygen
0.04% carbon dioxide
minor gases argon, neon, helium, methane , and ozone
0-4% water vapor, depending on temperature and humidity (avg 0.5%)
