Lecture 17 - Control of Respiration Flashcards
What follows immediately after phrenic n firing
Inspiration
What is the central respiratory center? Where is it located
Dorsal respiratory group and ventral respiratory group; medulla
Where is the botzinger and pre-botzinger complex?
Medulla in ventral respiratory group
What does the pre-botzinger control
Core respiratory rhythm
What does the pneumotaxic or pontine respiratory group control
Modifies inspiratory timing
These AP turn off inpsiration
Where is the pontine respiratory group
Pons
What controls the tidal volume
Dorsal respiratory group
What does the ventral respiratory group control
Inspiration, expiration, depth
It coordinates all these
What does the caudal portion of the VRG do
Premotor to upper airways (other expiratory muscles)
What does the rostral portion of the VRG control
Premotor to phrenic (other inspiratory muscles)
What modifies the DRG with sensory input
Vagus and glossopharyngeal nn
When is the VRG inactive
Quiet breathing
What does the ventral respiratory group excite
Expiratory muscles (intercostals and abdominals)
Increased firing of the pneumotaxic center does what
Signals for increased RR
What happens when you lesion the PRG
Failure to terminate inspiration
What change in firing levels in the DRG would you expect with:
Increased CO2
Decreased O2
Increased H+
All would result in increased firing
What do chemoreceptors do in relation to RR
When they are active they work to increase RR
Where are the central chemoreceptors located
Ventral surface of the medulla
They are sensitive to changes in H+ and CO2
Central chemoreceptors are sensitive to O2 at what level
Below 60 mm Hg
Where are peripheral chemoreceptors
Aortic arch and carotid body
What are peripheral chemoreceptors sensitive to
CO2 and H+
Are central or peripheral chemoreceptors faster to respond
Peripheral
What do peripheral chemoreceptors do to effect change
Increase RR and Vt
What type of specialized cells are found in peripheral chemoreceptors
Glomus cells detect PO2 and their Vm changes and they release that to an afferent fiber
What do the central chemoreceptors effect
Increased RR, response to hypercapnia
How do central chemoreceptors measure H+ and CO2
They sample CSF pH and CO2 of plasma
What do the mechanoreceptors in the airways do
They respond to stretch
How do mechanoreceptors communicate with the brain
Vagus
What do the mechanoreceptors firing cause
Inhibition of inspiration or prolonged expiration
What are mechanoreceptor activations sometimes called
Hering-Breuer expiratory reflex
What do the rapid adapting mechanoreceptors do
They are in the airway and react to irritants and produce coughing
What do the J receptors do
Produce coughing and tachypnea
What is the J receptor stimulus
Pulmonary edema
Where are J receptors located
Near capillaries
When does the cortex take over breathing
When talking or holding your breath
