Control of Vent Flashcards
The Dorsal Respiratory Group (DRG) receives impulses from
Glossopharyngeal(9), Vagus(10)
Where is the Dorsal Respiratory Group(DRG) located?
Each side of the medulla.
Where does the DRG send impulses?
- inspiratory muscles
- phrenic nerve diaphragm
- some impulse to the spinal nerves
The Ventral Respiratory Group (VRG) is located where?
Medulla, anterior to DRG
Which respiratory group is active during inspiration and expiration?
VRG
What areas do the VRG stimulate?
Accessory muscles of inspiration & expiration
What does the ramp signal do?
It stimulates the inspiratory muscles. It increases steadily for 2 sec.
What happens to the ramp signal that causes expiration?
It abruptly stops for 2-3 seconds
Where is the pneumotaxic center located?
In the Upper Pons.
Where does the pneumotaxic center transmit impulses to?
The respiratory System
Define obstructive sleep apnea.
Nothing to do with ventilatory drive. Mechanical obstruction of the airway.
Define central sleep apnea (ondines curse).
No attempt to breath. Not in response to elevated CO2.
** don’t cheat on water nymphs**
What center controls the ramp signal switch?
The pneumotaxic center
What does a weak impulse from the pneumotaxic center do?
Increased depth in breathing and a decreased rate.
What does a strong impulse from the pneumothorax center do?
Decreased in depth and an increase in rate
Where is the apneustic center located?
Lower pons
How does the apneustic center cause greatly prolonged inspiration (10-20 sec)
It signals to the DRG to prevent ramp shutoff.
What center is the apneustic center normally over-ridden by?
The pneumotaxic center
Cerebrovascular disease /trauma can cause what ventilatory drive abnormalities
Occlusion, hemorrhage. Can damage respiration center
____ will cause swelling inside the skull, will pinch arteries (blood wall) against the skull
Cerebral Edema
Name the three type of drugs that depress the respiratory centers.
Anesthesia, Narcotics, Barbiturates
Cessation of breathing for >10 sec for +30 times a night.
Sleep apnea
Where are the chemosensitive areas of the medulla?
Near the DRG and the VRG
What is primary stimulus of ventilation chemoreceptors in the CSF?
[H+]
What does the stimulation of chemoreceptors cause?
Stimulation of the inspiratory center
How long does it take for chronically high [H+] to be buffered in the CSF?
24-48 hours
Name 4 ways the body will respond to high altitude (low PIO2)
1) low PaO2 ( will stimulate peripheral chemoreceptors to increase VA)
2) increased flow(V) causes PaCO2 to drop
3) CO2 in CSF (diffuses into blood and CSF becomes alkalotic
4) excess bicarb
Name 2 places that the peripheral chemoreceptors are located.
- Carotid bodies( at the bifurcation of the carotid arteries)
- Aortic bodies (in the aortic arch)
Define (SIDS)
Most common in low birthweight infants (up to 4 months).
Have longer periods of apnea than other infants.
Exact mechanism in question (unknown)
Sudden cold that causes cessation of breathing and redistributing of circulation to vital organs.
Diving reflex
The _________ _________ is activated by stretch receptors in the airways. The stretch receptors are stimulated when the lungs are ________ -_______. Sends signals to the ______ &______ . Terminate ramp signal causes you to stop _______ and exhale.
Hering-Breur Reflex
Over-inflated
Vagus and DRG
Inhalation
Which nerve innervates the carotid bodies.
9 glossopharyngeal
Which nerve innervates the aortic bodies.
10 vagus
Name 4 effects of low PaO2?
- low PaO2 makes bodies more sensitive to increase in [H+]
- greatest stimulation PaO2 30-60mmHg
- PaO2 sensitivity is a problem with anemia.
- because sensitive to increase in [H+] in blood, can respond to metabolic acidosis
The three theories for why exercise increases ventilation.
1) increased CO2, decreased O2
2) brain stimulates muscle contraction @ sane time sends impulses to medulla to Alveolar flow
3) movement of muscles stimulates peripheral proprioceptors
