Physiology 3 - Control of Respiration Flashcards
Name the respiratory rhythm pacemaker cells in the medulla
Pre-Botzinger Complex
Which neurons do the pre-botzinger neurons stimulate to cause inspiration?
Activated pre-botzinger neurons stimulate dorsal respiratory neurons which contract inspiratory muscles
Which neurons cause hyperventilation (active expiration) and how are they activated?
Increased stimulation of the dorsal respiratory neurons activates the ventral respiratory neurons.
ventral respiratory neurons activate expiratory muscles (abdominal & internal intercostals)
Which neurons do not participate in normal quiet breathing?
Ventral respiratory neurons
Name the neuronal centre in the pons which terminates inspiration? And how is group of neurons activated?
Pneumotaxic centre (PC).
Activated when dorsal respiratory neurons are stimulated.
Which neuronal centre in the pons causes prolonged inspiration?
Apneustic Centre (AC).
Where are peripheral chemoreceptors located?
Carotid and Aortic bodies
What is the Hering-Breur inflation reflex?
A reflex triggered to prevent the over-inflation of the lung.
Pulmonary stretch receptors present on the wall of bronchi and bronchioles of the airways respond to excessive stretching of the lung during large inspirations.
Where are J receptors located?
J receptors are located within the alveolar walls in juxtaposition to the pulmonary capillaries of the lung, and are innervated by fibers of the vagus nerve.
Which receptors does oedema or PE activate?
J receptors
Where are central chemoreceptors located?
Surface of medulla
Central chemoreceptors detect H+ in CSF. How does H+ get into the brain?
CO2 readily diffuses across BBB.
CO2 conversion to bicarbonate creates H+, causing hyperventilation.
Define hypoxia
Inadequate supply of O2 to tissues
Define hypoxaemia
Lowered blood O2 content
Define hypercapnia
Build up of CO2 in blood
