Type 1 glomus cell secrete neurotransmitter because of oxygen sensitive
High-Yield Explanation
Type I glomus cells have O2 sensitive K+ channels, whose conductance is reduced in propoion to the degree of hypoxia to which they are exposed. This reduces the K+ efflux, depolarizing the cell and causing Ca2+ influx, primarily L-type Ca2+ channels. The Ca2+ influx triggers action potentials and transmitter release, with consequent excitation. of the afferent nerve endings. The smooth muscle of pulmonary aeries contains similar O2-sensitive K+ channels, which mediate the vasoconstriction caused by hypoxia. This is in contrast to systemic aeries, which contain adenosine triphosphate (ATP) dependent K+ channels that permit more K+ efflux with hypoxia and consequently cause vasodilation instead of vasoconstriction. Ref: Ganong's Review of Medical Physiology, 23rd edition, page no: 628, 629 Ref image: