Respiration Flashcards
What is the process underlying respiration in humans?
- Both ventilation (breathing) and transport of blood gases in the blood stream are accomplished by convection (bulk flow) and depend on a difference in total pressure
- Gas exchange at the lungs and at the level of tissues/cells is accomplished by diffusion and depends on the difference in the partial pressure of a given gas
What are the four basic steps of respiration?
- Ventilation or gas exchange between the atmosphere and air sacs (alveoli) in the lungs
- Exchange of O2 and CO2 between air in the alveoli and the blood in the pulmonary capillaries
- Transport of O2 and CO2 by the blood between the lungs and the tissues
- Exchange of O2 and CO2 between the blood in the systemic capillaries and the tissues
What is the CO2 production of a normal individual at rest?
200ml/min
What is the O2 consumption of a normal individual at rest?
250ml.min
What is the respiratory quotient (RQ)?
the ratio of CO2 produced to O2 consumed = 0.8 = 8 molecules of CO2 produced for every 10 molecules of O2 consumed
What is gas exchange at the lungs and at the level of tissues/cells accomplished by? What does it depend on?
diffusion
- depends on difference in the partial pressure of a given gas
what are ventilation and transport of blood gases in the blood stream accomplished by? What do they depend on?
convection
- depend on a difference in total pressure
What are the major structures in the upper airways?
- nose, mouth, pharynx (throat), larynx(vocal cords)
Excluding the structures of the upper airway, what are the other respiratory airway structures?
- Trachea, right bronchus, carina, left bronchus, and the diaphragm
What is the upper airway?
a multipurpose passage for air, solid and liquid food and a common structure for breathing, digestion and phonation
What is the function of the Uvula?
closes the naso-pharynx during swallowing and inhibits nasal regurgitation
What is the function of the epiglottis?
movement of hyoid bone during swallowing brings it down stopping food from entering the trachea and directs food into the esophagus
What are the vocal cords/vocal folds and what are their function?
folds of mucous membrane that lie across the laryngeal opening and allow for phonation and prevent aspiration of food
How many muscles control the position of the 4 structures of the airway in order to keep it closed during swallowing and open during breathing? (upper airway dilators)
20 muscles
What are the 4 structures whose positions are regulated by the 20 upper airwayd dilators?
- soft palate
- tongue
- hyoid apparatus
- pharyngeal wall
What happens during obstructive sleep apnea with regards to the airway dilators?
decreased genioglossus muscle activity leads to obstruction of the airway by the tongue
What are the functions of the upper airway mucosal lining?
to heat and humidify the inspired air
How does the mucosal lining of the upper airway effect inspiration?
heat and moisture from the mucosal lining heats and humidifies the inspired air to 37 degrees, saturated water vapor
How does the mucosal lining of the upper airway recover from the heat and moisture lost during inspiration?
air releases heat and moisture during exhalation, partially warming and humidifying the mucosa. the remaining is from the systemic blood supplying the airways
What happens to the regulation of heat and moisture in a patient with a tracheostomy?
the trach tube usually has heating and humidifying functions, otherwise air would be cold and dry
How many lobes do the left and right lung have?
left = 2 lobes right = 3 lobes
What are the structures involved in the tracheobronchial tree?
- trachea, carina, left primary bronchus, right primary bronchus
What is a characteristic of the tracheobronchial tree in terms of branching?
every parent structure has two or more daughter structures (usually 2 but sometimes more)
What structures are part of the conducting zone?
trachea, bronchi, bronchioles and terminal bronchioles