Respiratory System Flashcards
What occurs to the diaphragm in inspiration?
It contracts to expand the lungs
What occurs to the diaphragm in expiration?
It relaxes to decrease the volume of the lungs
What is the total volume of the lungs?
6 litres
What are the components of total lung volume?
- Inspiratory Reserve Volume (IRV)
- Tidal Volume (TV)
- Expiratory Reserve Volume (ERV)
- Residual Volume (RV)
What are the components of vital capacity?
-Everything but Residual Volume
What is tidal volume?
Amount of air inhaled or exhaled in one breath
What is Inspiratory Reserve Volume (IRV)?
Amount of air in excess of tidal inspiration that can be inhaled with maximum effort
What is expiratory reserve volume (ERV)?
Amount of air in excess of tidal expiration that can be exhaled with maximum effort
What is residual volume (RV) and what is its purpose?
Amount of air remaining in the lungs after maximum expiration; keeps alveoli inflated between breaths and mixes with fresh air on next inspiration
What is Vital Capacity (VC) and what is it used to assess??
Amount of air that can be exhaled with maximum effort after maximum inspiration; used to assess thoracic muscle strength and pulmonary function
What is Inspiratory Capacity (IC)?
Maximum amount of air that can be inhaled after a normal tidal expiration (TV + IRV)
What is functional residual capacity (FRC)?
Amount of air remaining in the lungs after a normal tidal expiration (RV + ERV)
What is the typical value for Tidal volume (TV) at rest?
500ml
What is the typical value for Inspiratory Reserve Volume (IRV) at rest?
3000ml
What is the typical value for Expiratory Reserve Volume (ERV) at rest?
1200ml
What is the typical value for Residual Volume (RV) at rest?
1200ml
What is the typical value for Vital Capacity (VC) at rest?
4700ml
What is the typical value for Inspiratory Capacity (IC) at rest?
3500ml
What is the typical value for Functional Residual Capacity (FRC) at rest?
2400ml
What is the typical value for total lung capacity at rest?
5900ml
What are the functions of the respiratory system?
- Provides Oxygen
- Removes CO2
- Regulates pH
- Forms speech
- Defends against microbes
- Traps and dissolves blood clots
What is the conducting zone of the respiratory system?
Trachea, Bronchi, Bronchioles, and Terminal Bronchioles
What is the respiratory zone of the respiratory system?
Respiratory bronchioles, Alveolar Ducts and Alveolar sacs
What is Boyle’s Law?
At a constant temperature, as volume increases, pressure decreases and vice versa
How does a contraction of the diaphragm by 1cm change pressure and thus volume?
Decreases pressure by 3mmHG, increasing volume by 500ml
Explain the exchange surface of your lungs?
- Surfactant
- Epithelium
- Basement Alveolar Membrane
- Interstitial Space
- Basement Capillary Membrane
- Endothelium
What is Dalton’s Law?
Each gas in a mixture exerts its own pressure.
What is the pressure of specific gas in a mixture called?
The partial pressure
What is the pressure of air?
760mmHG
What is henry’s law?
The quantity of a gas that will be dissolved in a liquid is proportional to the partial pressure of the gas and its solubility coefficient
Oxygen is relatively insoluble in water, so how is it carried in the blood?
-98% of it is transported by Haemoglobin found in erythrocytes
What is the Bohr Effect?
Haemoglobin affinity for oxygen is inversely related to the concentration of CO2/acidity. Less CO2 means higher partial pressure of oxygen, so higher affinity for oxygen, and vice versa
What part of the brain is respiration regulated by at rest?
Brainstem (Pons and Medulla Oblongata)
What are the different centres of the Pons in the brainstem that regulate respiration?
Pneumotaxic and Apneustic Centres
What are the two kinds of chemoreceptors involved in regulating respiration and where are they located?
Peripheral - in carotid bodies and aorta. Responds to changes in partial pressure of O2 and CO2
Central - located on medulla. Respond to changes in pH of spinal fluid
