Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
WEEK 16:
Distribution of inspired gases and gas transfer- SELF DIRECTED :(
| Question | Answer |
|---|---|
| factors influencing airway resistance (5) | airway smooth muscle tone, gravity/posture, lung compliance, age, and disease |
| smooth muscle is sensitive to what | neural and chemical stimulation |
| what happens when hyper-responsive smooth muscle contracts | airway narrows so airflow is obstructed |
| neural/chemical stimulation of smooth muscle refers to which nervous systems of ANS (2) | sympathetic (B2 adrenoceptor) and parasympathetic (M3) |
| treatment for asthma | salbutamol (stimulates bronchodilation) |
| describe gravity and posture at an upright position between the apex and base of the lung | higher blood volume and flow at the base and lower blood volume and flow at the apex |
| describe gravity and posture at a supine position between the apex and base of the lung | equal blood volume and flow in both the apex and base |
| compare airway resistance between an upright and supine position | higher in supine compared to upright due to gravity |
| lung compliance | stretchiness |
| example of lung diseases with decreased compliance (2) | pulmonary fibrosis and alveolar oedema |
| example of lung with increased compliance | normal ageing lung |
| compliance increases with what | age |
| loss in elastic recoil leads to what | prevents complete exhalation leading to a retention of CO2 |
| effective ventilation needs what (2) | lung distention and elastic recoil |
| describe emphysema in terms of compliance and elastic recoil | high compliance but low elastic recoil which prevents complete exhalation |
| describe pulmonary fibrosis in terms of compliance | low compliance so extra work is needed for ventilation |
| flow velocity in bronchi/ large bronchioles | high and turbulent |
| during an auscultation what should you hear in bronchi/ large bronchioles | breathe sound generation |
| during an auscultation what should you hear in small bronchioles | no sound generation |
| flow velocity in small bronchioles | laminar |
| how does flow in terminal airways occur | diffusion |
| small airways are known as what | silent zone |
| diffusion depends on what | gradients of partial pressures for O2 and CO2 |
| low diffusion resistance relies on (2) | respiratory membrane and gas permeability |
| explain the difference between how fast diffusion occurs in O2 and CO2 in gas | CO2 diffuses more slowly because it is a larger molecule (MW 44) than O2 (MW 32) |
| explain the difference between how fast diffusion occurs in O2 and CO2 in liquid | CO2 diffuses 21 times faster than O2 because CO2 is more soluble in water |
| gas transfer and respiration is controlled how (2) | neural regulation and chemical regulation |
| voluntary breathing is controlled by what | cerebral cortex |
| involuntary breathing is controlled by what | pons and medulla |
| where are central chemoreceptors found | medulla |
| what do CCRs do | detect changes in CO2 and pH |
| where are peripheral chemoreceptors (PCRs) | aortic arch and carotid arteries |
| what do PCRs do | detect changes in O2 |
| perfusion meaning | process where deoxygenated blood passes through lungs and becomes reoxygenated |
| ventilation perfusion rate (Va/Q ratio) | ratio of alveolar ventilation to blood flow |
| normal Va and Q | 5 |
| normal Va/Q | 1 |
| dead space ventilation perfusion ratio | normal ventilation (5) and impaired/no perfusion (0) so there is no capacity to carry O2 away or bring CO2 to alveoli so no gas exchange and alveoli equilibrates with atmosphere |
| shunt ventilation perfusion ratio | no ventilation (0) and normal perfusion (5) so no new O2 into system and alveoli equilibrates with venous blood |
| example of shunted blood | acute respiratory distress disorder due to inflammation/ injury |
| example of dead space | pulmonary embolus |
| apex Va/Q | low blood flow (3) and high ventilation (6) so 2 |
| base Va/Q | high blood flow (6) and low ventilation (3) = 0.5 |
| how do you used Va/Q to diagnose pulmonary embolism | V/Q scan using radioisotopes |
| how does a V/Q scan using radioisotopes work | injection (perfusion) and inhalation (ventilation) of radioisotope |
| ventilation perfusion matching depends on what | local autoregulation of blood flow |
| hypoxia in ventilation perfusion matching | low O2 constricts pulmonary arterioles to try direct the O2 to where it is needed |
| ventilation perfusion matching in foetus | high O2 which dilates pulmonary arterioles to optimise O2 delivery around the body |
| lung disease in ventilation perfusion matching | high CO2 dilates bronchioles so you can exhale more out and return levels back to normal |
| hypocapnia (low CO2) in ventilation perfusion matching | low CO2 constricts bronchioles to try increase it back to normal levels |
Created by:
kablooey
Popular Medical sets