Some functional properties of bulbar respiratory units

摘要: Abstract Respiratory neurons in the environs of nucleus ambiguus exhibit functional properties which fit them for roles as elements bulbar respiratory center. Some inspiratory begin to fire about 100–200 msec before start inspiration and proceeds other units come into play. These later constitute a reserve pool is called upon under conditions requiring deeper inspiration. Their discharge trains are lengthened their frequency markedly increased hypercapnic or hypoxic states. The early show firing rates same conditions, but it doubtful that any new recruited activity. expiratory population similarly constituted some just onset expiration proceeds. activity unit also during hypercapnia hypoxia few from late units. phasic more easily influenced by alterations gaseous content inspired air than tonic, other, medial reticular formation. Furthermore, give an immediate response pulmonary stretch, whereas tonically discharging formation no such response. Although located close ambiguus, they active properly suited general regulators whole movements.