Physiology Flashcards
At constant temp, as the volume of a gas increases, the pressure exerted _____ (Boyle’s Law)
Decreases
What is the function of external intercostal muscle in inspiration?
Lifts ribs up, pushes out sternum
What are the 2 main accessory muscles of respiration?
Scalenus
Sternocleidomastoid
What is meant by dynamic airway compression?
The rising intrapleural pressure during expiration compresses the alveoli and airway
V/Q ratio is better at the top of the lungs. True/False?
True
The amount of gas that will dissolve in a given volume is proportional to the ________ of the gas at equilibrium within the liquid (Henry’s Law)
Partial pressure
What is the Bohr Effect?
Increased release of O2 from Hb at tissues (sigmoid shifts to right)
What shape is the dissociation curve for myoglobin and oxygen?
Hyperbolic
Most CO2 is transported in the blood as what?
Bicarbonate
What is the Haldane Effect?
Removing O2 from Hb increases Hb’s affinity for CO2 and CO2-generated H+
i.e. O2 will be released at tissues; this will increase affinity of Hb for CO2; thus CO2 will be taken up from tissues!
When are ventral respiratory group neurones fired? What do they excite?
In active expiration (hyperventilation) after increased firing of dorsal respiratory group neurones
Excite secondary muscles of respiration
Chemoreceptors which sense tension of O2, CO2 and [H+] in the blood
Peripheral chemoreceptors
Where are peripheral chemoreceptors located?
Carotid + aortic bodies
Chemoreceptors which sense the [H+] of the CSF
Central chemoreceptors
Where are central chemoreceptors located?
Near the medulla
