The Respiratory System Flashcards
2 functional parts of respiratory system
- Conducting zone - filter and conduct air; nose to terminal bronchioles
- Respiratory zone - gas exchange bw air and blood; bronchioles, alveolar ducts, sacs
2 structural parts of the respiratory system
Upper and Lower respiratory systems
Type I vs type II alveolar cells
Type I alveolar cells - main sites for gas exchange
Type II - secrete alveolar fluid and surfactant to prevent alveoli from collapsing by lowering surface tension
Alveolar walls + capillary walls =
Respiratory membrane
– –, not to be confused with Pulmonary Ventilation, is gas exchange bw lungs and blood
External respiration
– – is gas exchange bw blood, interstitial fluids and cells
Internal respiration
When you INHale, you – size of lungs => alveolar pressure falls below atmospheric pressure
Increase size of lungs
During –, diaphragm m is contracting / getting smaller
Inhalation
The process of – decreases the size of the thoracic cavity
Exhalation
What reduces the surface tension of alveolar fluid (produces inward force on alveoli) during inhalation
Surfactant
– law of partial pressures
Dalton’s law of partial pressures
Molecular weight and solubility affects external and internal respiration rate such that – net diffusion > – net diffusion
CO2 > O2
70% of the co2 in our body exists in blood plasma as – –
Bicarbonate ions
Partial pressure of co2 is – in tissue capillaries
Partial pressure of co2 is – in pulmonary capillaries
Pco2 is high in tissue capillaries
Pco2 is low in pulmonary capillaries
Co2 enters blood stream => converted into carbonic acid => dissociates into bicarbonate and H+ ions
Thus, increase in Pco2 = – in blood pH
More co2 = more H+ = lower blood pH
The medulla oblongata of the CNS responds to changes in H+ and Pco2 in –
Cerebrospinal fluid
PNS responds to changes in Pco2 and H+ in the –
Blood
High systemic blood pco2 due to inadequate exhalation of CO2 => drop in blood pH => – –
Respiratory acidosis
Hyperventilation => low systemic blood Pco2 => respiratory –
Respiratory alkalosis bc low pco2 = reduced carbonic acid = reduced H+ ions = increase in pH
