Control of lung function Flashcards
What is the main function of medulla oblongata respiratory centres?
The control of ventilation arise from interactions of cranial regions, resulting in a rhythmic ventilation rate that provides the body with sufficient oxygen volume, whilst facilitating adequate carbon dioxide removal
Where are the respiratory centres located?
Medulla oblongata and pons
What are the four main respiratory centres?
Dorsal respiratory group
Ventral respiratory group
Apneustic centre
Pneumotaxic centre
What is the function of the dorsal respiratory group?
Involved in maintaining a constant breathing rhythm by stimulating the diaphgram and the intercostal muscles to contract
INSPIRATION
Which respiratory group is mainly focussed on inspiration ?
Dorsal respiratory group
What happens when the dorsal respiratory group activity decreases?
No longer stimulates diaphragm and intercostal to contract causing relaxation and expiration
What is the main expiratory centre?
The ventral respiratory group
Which centre causing forced expiration?
Ventral respiratory group
Which respiratory centre inhibits the apneustic centre?
Ventral respiratory group
Which respiratory centre stimulates the DRG?
Apneustic centre
What is the function of the apneustic centre?
Controls the depth of inspiration, for deep breathing
Double cluster of neuronal Bodies stimulates the neurones in the DRG
Which pontine respiratory centre inhibits the DRG?
Pneumotaxic centre
Which respiratory centre controls frequency and depth, & enables relaxation post inspiration?
Pneumotaxic centre
Which respiratory centre is classified as the inspiratory off switch?
Pneumotaxic centre
Which plexus of sympathetic and parasympathetic motor & visceral nerve fibres innervate the lung?
Pulmonary plexus
What is the pathway of nerve bundles taken during descent?
Nerve bundles descend parallel to the bronchial tissue & blood vessels
Which nerve contributes to parasympathetic motor fibres of the airways?
Vagus nerve
What is the effect of the vagus nerve on parasympathetic motor fibres on airways?
Regulates bronchoconstriction of airways. Autonomic excitatory cholinergic neves secrete acetylcholine into the bronchial smooth muscle & submucosal glands.
Bronchoconstriction & mucous production
Which hormone causes airway bronchodilation?
Noradrenaline
Vasoactive intestinal peptides, neural nitric oxide
Describe the pathway of sympathetic nerve fibreo the superior cervical ganglion?
Preganglionic neurones pass through the sympathetic chain of ganglia, synapsing with post ganglionic neurones the superior cervical ganglion
Which pulmonary ganglion contains postganglionic sympathetic cell bodies?
Superior cervical ganglion
Which nerves form the phrenic nerve?
C3, C4, C5
Which nerve innervates the diaphragm contraction?
Phrenic nerve
What is the primary muscle of respiration?
Diaphragm
What is the effect of diaphragmatic contraction?
Reduced intrathoracic pressure
Describe the endothelial arrangement of the blood brain barrier
Compact forming the blood barrier - continuous capillary structure with additional tight junctions
What type of capillary forms the blood barrier?
Continuous capillary
What type of junction supports the blood brain barrier?
Tight junctions
Describe the relationship with proton concentration and carbon dioxide:
Proton concentration is proportional to carbon dioxide proportion
Which enzyme is responsible for the activity of carbonic acid?
Carbonic anhydrase