Ventillation And Control Flashcards
What muscles are used in inspiration and through which nerves?
External intercostal (intercostal nerves) Diaphragm (phrenic nerve)
Where is the respiratory Center located in the brain?
The pons and medulla
Action potentials in the DRG travel to which muscles?
Inspiration muscles (External intercostal and diaphragm)
What might alter the autonomic rhythm of the respiratory centres?
Emotion
Voluntary over-ride (via higher centres in the brain)
Mechano-sensory input from the thorax (stretch reflex)
Chemical composition of the blood detected by chemoreceptors
Where does the action potentials which reach the expiratory muscles come from?
The ventral respiratory group (of neurones)
VRG
Where are the central and peripheral chemoreceptors found?
Medulla - central
Carotid and aortic bodies - peripheral
What does the central chemoreceptors respond to?
Respond directly to H+ (which directly reflects c02)
What does the peripheral chemoreceptors respond to?
Plasma H+ and PC02
What is the primary ventilator drive?
Central chemoreceptors
Hypercapnea will primarily be detected by which chemoreceptors?
Raised C02 (hypercapnea) will result in an increase in H+ therefore will be detected firstly by the central chemoreceptors
Central chemoreceptors do not respond to direct changes in what?
Plasma H+ (only respond to changes in H+ in CSF around the brain)
What chemoreceptors respond to an increase in arterial Pc02?
Primarily the central chemoreceptors.
C02 will cross the blood brain barrier and form bicarbonate and H+
The central chemoreceptors will respond indirectly to the H+ and bring about ventilation
What chemoreceptors will respond to a decrease in arterial Pa02?
Peripheral chemoreceptors
Changes in plasma PH will alter ventilation via what chemoreceptors?
Peripheral chemoreceptors
If plasma PH falls what will happen to ventilation?
Rise in PH = rise in H+
Therefore ventilation will be stimulated
