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
The Description of the Human Body soul. A sick or injured body does not do what we want or moves in ways we do not want. He believed the death of the body stopped it from being fit to bring about movement. This did not necessarily happen because the soul left the body. René Descartes believed the body could exist through mechanical means alone. This included digestion, blood circulation, muscle movement and some brain function. He felt we all know what the human body is like because animals have similar bodies and we have all seen them opened up. He saw the body as a machine.