Control of Ventilation- Scharf Flashcards
What is apneustic breathing?
Cut in the pneumotoxic center (midway through the pons). Sharp inhale and long exhale.
What is pneumotaxic breathing?
Irregular impuse breathing with a few short breaths at a time. Cut at 1 in uppermost part of pons.
What is the nucleus tractus solitarius (NTS)
Respiratory rhythm generator in the medulla. Allows for voluntary input and integrates together with cardiorespiratory afferents and the brain. Passes its input to the ventrolateral medullary nucleus (VML) which coordinates autonomic efferents.
Effect of CO2 and opiates on ventilatory response
CO2 increases ventilations but opiates dampen the response. Higher slope from lower PO2.
What is P(.1)
Measures neural stimulation but cutting off the airway and measuring pressure drop in first 100ms
If the ventilation decreases, how does the neural stimulation change in an asthma patient and a COPD patient?
Asthma: P.1 goes up because there is a mechanical problem and the neural stimulation is trying to compensate.
COPD (or opiates): P.1 goes down because there is a neural defect.
A neural stimulant won’t help the asthmatic but will improve COPD.
What are central chemoreceptors?
Located near the pneumotaxic center in the CSF in the medulla. Responds to differences in CO2 through pH changes. Little hypoxic response.
What are the peripheral arterial system receptors?
Located in the carotid sinus and aortic arch, through vagus to the NTS from chemoreceptor cells. Control ventilation. Give maximum response with PO2 <50 (because of Hgb curve). Respond to hypoxia and pH. Carotid is most important between the two. Little hypercapnia response.
What is the effect of altitude on the respiratory center in the brain?
Hypoxia (lower PP), peripheral response increases ventilation and drop PCO2, leading to CSF alkalosis. Buffer systems in CSF normalize pH: ion pumps export bicarbonate and secondarily increase ventilation because CSF.
What is the effect of setting a patient on a ventilator with good oxygenation but low CO2?
CSF compensates by decreasing the pH and when ventilator removed goes into respiratory acidotic failure.
What is the Herring-Breuer reflex?
Inflation of the lungs inhibits further inspiratory muscle activity. Reason why take a deep breath before hodling it-easier to hold breath at TLC. Slowly adapt, fire for a while, then slow.
What is Head’s reflex?
Inflation of the lungs stimulates further inflation of the lungs. Mostly for babies after birth. Reflex is quickly acting and adapting to slow again.
What are irritant receptors?
For when food goes down the wrong tube, epithelial cells cause coughing.
What are J receptors?
Out in parenchyma, check for fluid in order to compensate by increasing ventilation.
What are Cheynes stokes breaths?
Rapid breathing and then apnea phases.
In CHF: poor prognosis
Altitude
Neurologic conditions
Theory 1(old): Due to flow delay between lungs and central chemoreceptors
Theory 2: related to increase in ventilatory controller gain
