REGULATION OF BREATHING AND COUGH Flashcards
What is Dalton’s law?
Total partial pressure = partial pressure of each gas added together
What is partial pressure?
The concentration of a gas in a mixture of gases
Which nerve innervates the diaphragm?
The phrenic nerve C3-C5
Which muscles can help with breathing?
Accessory muscles - abdominal muscles
What is hypercapnia?
A rise in partial pressure of CO2
What is hypocapnia?
Fall in partial pressure of CO2
What is hypoxia?
Fall in partial pressure of oxygen
Describe the carbonic acid-bicarbonate buffer system?
Carbon dioxide dissolves to form carbonic acid which dissociates and forms hydrogen ions and bicarbonate ions.
What is respiratory acidosis?
When hypoventilation causes increased partial pressures of carbon dioxide so plasma pH falls
What is respiratory alkalosis?
Hyperventilation leads to a decrease in partial pressures of CO2 so plasma pH increases
What are peripheral chemoreceptors?
They are found in carotid and aortic bodies and monitor partial pressures of oxygen in the blood. They only react when pO2 falls close to 8kPa and then they signal to the brain stem to increase Br and Hr and change the distribution of blood to prioritise more crucial tissues
What are central chemoreceptors?
Receptors sitting in CSF and detect minuscule changes in pH so that ventilation rates can be altered to maintain homeostasis of pH
What are the 2 types of respiratory failure?
Type 1 = hypoxia and normal to low pCO2
Type 2 = hypoxia and hypercapnia
What is a productive cough?
A cough that produces mucus
Describe the cough reflex?
Cough receptors are triggered and I put,she’s then travel via the vagus nerve to the medulla. The efferent neural pathway is then via the vagus, phrenic nerves and spinal motor neurones to all the effector organs (larynx, trachea, bronchi, diaphragm, exploratory muscles)
