Carotid body A decrease in oxygen partial pressure, an increase in carbon dioxide partial pressure, and a decrease in arterial pH can all cause depolarization of the cell membrane, and they affect this by blocking potassium currents. This reduction in the membrane potential opens voltage-gated calcium channels, which causes a rise in intracellular calcium concentration. This causes exocytosis of vesicles containing a variety of neurotransmitters, including acetylcholine, noradrenaline, dopamine, adenosine, ATP, substance P, and met-enkephalin. These act on receptors on the afferent nerve fibres which lie in apposition to the glomus cell to cause an action potential. The feedback from the carotid
Carotid triangle still more inferiorly, the external branch of the same nerve. The upper portion of the larynx and lower portion of the pharynx are also found in the front part of this space. Carotid triangle The carotid triangle (or superior carotid triangle) is a portion of the anterior triangle of the neck. It is bounded: It is (covered) by the integument, superficial fascia, Platysma and deep fascia; Its floor is formed by parts of the -1 Thyrohyoid membrane, -2Hyoglossus, and the -3Constrictores pharyngis medius and inferior. The external and internal carotids lie side by side, the external being the more anterior