PULMONARY PLEXUSES
P 1307 Gray's:
Lest we forget, the lungs bud off the foregut in the embryo. The esophagus and the trachea are originally one tube, that separates into two.
P 1307 Gray's:
PULMONARY PLEXUSES
These are anterior and posterior to the other hilar structures of the lungs, the anterior plexus being much smaller. According to Mizeres (1963) they are extensions from the cardiac plexus along the right and left pulmonary arteries. They are formed by vagal and sympathetic branches. Efferent parasympathetic fibres arise from the dorsal vagal nucleus; efferent sympathetic fibres are postganglionic branches of the second to fifth thoracic sympathetic ganglia.
The anterior plumonary plexus is formed by rami from vagal and cervical sympathetic cardiac nerves as well as direct branches from both sources; the posterior plumonary plexus is formed by the rami of vagal cardiac branches from the second to fifth or sixth thoracic sympathetic ganglia, the left plexus also receiving branches from the left recurrent laryngeal nerve. The two plexuses are interconnected; from them nerves enter the lung as networks along branches of the bronchi and pulmonary and bronchial vessels extending as far as the visceral pleura. There are small ganglia within the tracheobronchial tree of the airways with which efferent vagal preganglionic fibres synapse (Coburn 1987). They may act as sites of integration and/or modulation of the input from extrinsic nerves or permit some local control of aspects of airway function by local reflex mechanisms (Allen & Burnstock 1990). In the small intestine interstitial cells have been described in terminal autonomic networks, but have not been seen in thoracic organs, apart perhaps from the oesophagus (Dijkstra 1969). Efferent vagal fibres are bronchoconstrictor, secretomotor to bronchial glands and vasodilator. Efferent sympathetic fibres are bronchodilator and vasomotor.
These are anterior and posterior to the other hilar structures of the lungs, the anterior plexus being much smaller. According to Mizeres (1963) they are extensions from the cardiac plexus along the right and left pulmonary arteries. They are formed by vagal and sympathetic branches. Efferent parasympathetic fibres arise from the dorsal vagal nucleus; efferent sympathetic fibres are postganglionic branches of the second to fifth thoracic sympathetic ganglia.
The anterior plumonary plexus is formed by rami from vagal and cervical sympathetic cardiac nerves as well as direct branches from both sources; the posterior plumonary plexus is formed by the rami of vagal cardiac branches from the second to fifth or sixth thoracic sympathetic ganglia, the left plexus also receiving branches from the left recurrent laryngeal nerve. The two plexuses are interconnected; from them nerves enter the lung as networks along branches of the bronchi and pulmonary and bronchial vessels extending as far as the visceral pleura. There are small ganglia within the tracheobronchial tree of the airways with which efferent vagal preganglionic fibres synapse (Coburn 1987). They may act as sites of integration and/or modulation of the input from extrinsic nerves or permit some local control of aspects of airway function by local reflex mechanisms (Allen & Burnstock 1990). In the small intestine interstitial cells have been described in terminal autonomic networks, but have not been seen in thoracic organs, apart perhaps from the oesophagus (Dijkstra 1969). Efferent vagal fibres are bronchoconstrictor, secretomotor to bronchial glands and vasodilator. Efferent sympathetic fibres are bronchodilator and vasomotor.
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