Ch. 13 - Respiratory Physiology Flashcards
What is the formula for total lung volume?
TLV = Inspiratory Reserve Volume + Tidal Volume + Expiratory Volume + Residual Volume
What is the formula for Vital Capacity?
VC = TLV - RV
What is air inspired with maximal inspiratory effort (after inspiring at TV)?
Inspiratory Reserve Volume (IRV)
What is air inspired or expired with a normal breath called?
Tidal Volume
Is Residual Volume increased or decreased in older individuals and those with COPD and asthma? And why?
Decreased because of air trapping
What are the muscles of inspiration?
- Diaphragm
- Accessory Muscles
- Scalenes
- Sternocleidomastoid
- Trapezium
- External intercostals
What are the muscles of expiration?
- Internal intercostals
- Abdominal
What is a good gauge for breathing effectiveness?
Alveolar Ventilation
What is the normal Tidal Volume and Dead Space volume?
- TV = 500 mL
- Dead Space = 150 mL
- 350 mL used for alveolar ventilation
What is the histology of the conducting zone airways?
- Pseudostratified ciliated columnar
- Goblet and Mucous cells secrete mucous
What type of cells produce surfactant?
Type II epithelial cells
What 4 things does gas exchange in the lungs depend on?
- Partial pressure gradient
- Gas solubility
- Thickness of membrane
- Alveolar surface area
What factors cause a left shift in the Hemoglobin dissociation curve (favoring O2 uptake)?
- Increase pH
- Decrease 2,3-DPG
- Decrease temperature
- CO
- Low PO2
What causes a right shift in the hemoglobin dissociation curve (favoring O2 release)?
- Low pH
- High PCO2
- High 2,3-DPG
- High temperature
- High PO2
How is carbon dioxide mostly carried in the blood?
Bicarbonate in the serum
What enzyme found within the RBC is responsible for producing the bicarbonate for the Chloride shift?
Carbonic anhydrase
What are the causes of hypoxemia?
- Low FiO2
- Hypoventilation
- V/Q mismatch
- Shunt
- Diffusion limitation
What is the compensation mechanism for hypercarbia (increase of CO2 in blood)?
Hyperventilation
How can you terminate a hyperventilation attack?
- Increase PCO2
- Breathe in and out in a bag
Which respiratory chemoreceptors are affected by increase in PCO2, H+ and low O2 levels?
Periperheral, Carotid and Aortic bodies
What do the central medullary respiratory chemoreceptors respond to?
- High H+ in CSF, brain interstitial fluid
How can you tell the difference between the carotid and aortic bodies from carotid sinus and aortic baroreceptors?
- Body = chemoreceptors
- Sinus = baroreceptors
What are the primary respiratory processes and the primary metabolic processes?
- 1˚ respiratory - respiratory acidosis/alkalosis -> metabolic compensation
- 1˚ metabolic - metabolic acidosis/alkalosis -> respiratory compensation
What is the reflex to prevent overinflation?
Hering-Breuer Reflex
What is the compensation for respiratory acidosis?
Metabolic
- Buffers act like bases
- Kidneys increase H+ secretion, reabsorption of HCO3- and synthesis of HCO3-
What is the compensation for respiratory alkalosis?
Metabolic
- Buffers act like acids
- Kidneys decrease H+ secretion, reabsorption of HCO3- and synthesis of HCO3-
What is the compensation for metabolic acidosis?
Repiratory
- Buffers act like bases
- Lungs undergo hyperventilation
- Kidneys increase their secretion of H+, reabsorption and synthesis of HCO3-
What is the compensation for metabolic alkalosis?
Respiratory
- Buffers act like acids
- Lungs undergo hypoventilation
- Kidneys decrease H+ secretion, reabsorption & synthesis of HCO3-
