Respiratory Changes Pt. 1 Flashcards
What catalyzes the reaction of water and carbon dioxide to form carbonic acid?
Carbonic anhydrase in red blood cells
What does carbonic acid dissociate into?
Hydrogen ions and bicarbonate ions
What replaces bicarbonate ions as they leave the red blood cells?
Chloride ions
What does carbon dioxide react with when bound to hemoglobin and other plasma proteins?
Amine radicals
What gas competes with oxygen for binding sites on hemoglobin?
Carbon monoxide (CO)
Which has an increased affinity for hemoglobin: CO or O2?
CO (250X)
How much CO partial pressure is required to saturate 97% of hemoglobin and decrease oxygen carrying capacity by 50%?
Small PP (PCO = .4 mmHg)
What amounts of carbon monoxide are considered lethal?
.1% CO or PCO = .6 mmHg
How is CO poisoning treated?
With 95% O2 and 5% CO2
Why is CO poisoning also treated with CO2 in addition to the expected O2?
Increased ventilation function
How does the usual CO poisoning treatment work?
Rapid displacement of CO
What is the physiologic role of CO when produced by the body in SMALL quantities?
Signaling molecule in nervous system
Vasodilator
Small quantities of CO produced by the body have an important role is what body systems?
Immune, respiratory, GI, kidney, and liver
The goals of neural regulation of ventilation are to keep arterial levels of what gasses constant?
Oxygen and carbon dioxide
The nervous system adjusts the level of ventilation to match what?
Perfusion of the lungs (pulmonary blood flow)
What makes up the level of ventilation that is regulated by the nervous system?
Respiratory rate and tidal volume
By matching ventilation with pulmonary blood flow (CO), what else is automatically matched to ventilation?
Overall metabolic demand
Where is the dorsal respiratory group located?
Nucleus tractus solitarius in medulla
The dorsal respiratory group is associated with the termination of which cranial nerves?
IX and X
From where does the dorsal respiratory group receive input?
Peripheral chemoreceptors
Baroreceptors
Receptors in the lungs
The dorsal respiratory group self excites what group of muscles?
Muscles of inspiration
What area of neural control of ventilation sets the basic drive of ventilation?
Dorsal respiratory group
Explain the ramp like signaling of the dorsal respiratory group.
2 seconds on followed by 3 seconds off (self-excitation)
Which ventilatory neural control center has the opposite effect of the apneustic center?
Pneumotaxic center
What is the location of the pneumotaxic center?
Dorsally in the nucleus parabrachialis of upper pons