Exam revision Flashcards
What are the three most common pulmonary function tests?
- Total ventilation - the total amount of gas in/out in a minute - forced vital capacity (VFC) - gas forcibly expelled after a deep breath - Forced expiratory volume (FEV) - amount expelled during specific time intervals of the FVC
How are lungs innervated?
- parasympathetic motor fibres- cause air tubes to constrict - sympathetic motor fibres- causes air tubes to dilate - visceral sensory fibres - responsible for the cough reflex, etc
What are respiratory volumes?
Tidal volume (TV) - volume of air incoming and outgoing in 1 quiet breath. Inspiratory reserve volume (IRV) - volume of air incoming in 1 forced inhalation. Expiratory reserve volume (ERV) - volume of air that can be forcibly expired after normal exhalation Residual volume (RV) - volume of air that remains in the lungs after exhalation to keep alveoli open and prevent lung collapse.
What are respiratory capacities?
Inspiratory capacity (IC) - total amount of air that can be inspired (TV+IRV) Functional residual capacity (FRC) - amount of air remaining in the lungs after normal tidal volume expiration (RV+ERV) Vital capacity (VC) - total volume of exchangable air (TV+IRV+ERV) Total lung capacity (TLC) - (TV+IRV+ERV+RV)
What is the Bohr effect?
A shift to the right on the O2 saturation scale. A weakening of the haemoglobin-oxygen bond Happens when temperature increases or blood pH decreases
What is the Haldane effect?
Oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin which increases the removal of carbon dioxide. Conversely, oxygenated blood has a reduced affinity for carbon dioxide
What is the Reticular Activating System?
- RAS - an area in the brain stem - sends stimuli to the cerebral cortex to keep you alert - has a role in the sleep stages
How does the hypothalamus relate to sleep?
- Inhibits RAS - Induces and regulates sleep - releases acetylcholine, a ‘wake up’ chemical
