Unit 5 Flashcards
Ventilation
Gas exchange between the atmosphere and the lungs.
Expiration
Air moves out of the lungs (exhalation). Somatic motor neurons stop firing to trigger it. Passive for quiet breathing and active during exercise or heavy breathing.
Lungs
The main organ of the respiratory system.
Thorax
Chest.
Pleural Fluid
Between the pleural sac layers which acts as a lubricant.
Larynx
Voice box.
Bronchioles
Branches off of the bronchi.
Compliance
The ability for the lung to stretch. The lower it is, the harder it is to expand the lungs (ie. inhalation).
Surfactant
Reduces surface tension to prevent collapsing of the alveoli.
Bronchoconstriction
Caused by histamine and parasympathetic neurons.
Spirometer
An instrument that measures movement of air during breathing.
Expiratory Reserve Volume (ERV)
The amount of air that can be exhaled after a normal expiration.
Vital Capacity (VC)
The maximum amount of air that can be voluntarily moved into or out of the respiratory system.
Inspiratory Capacity
The sum of the tidal volume and the inspiratory reverse volume.
Ventilation Rate
The amount of air inhaled or exhaled over a given amount of time.
Alveolar Ventilation
The amount of air that reaches the alveoli each minute. Is a more accurate indicator of efficiency of ventilation.
Perfusion
The flow of blood to the alveolar capillaries.
Hypoxia
Lack of oxygen. Results in tissue death.
Dissociation Curve
A graph that highlights the relationship between the partial pressure of oxygen and hemoglobin saturation.
Carbonic Anhydrase
Catalyzes the reaction of carbon dioxide into bicarbonate.
Central Chemoreceptors
Located in the medulla oblongata (most important chemical controller of ventilation). Activated when CO2 crosses the blood brain barrier into the cerebrospinal fluid (CSF) resulting in changes in pH. Senses changes in pH in the CSF not the arterial blood.
Aortic Body
Peripheral chemoreceptors found near the aorta.
Partial Pressure
The partial pressure of an atmospheric gas is equal to the atmospheric pressure times the percent gas in the atmosphere.
Inspiration
Air moves into the lungs (inhalation). Somatic motor neurons trigger it.