On/off switching of capillary vessel flow controls mitochondrial and glycolysis pathways for energy production

Capillary vessel flow in the base of the fingernail can be observed by microscopy. This flow is switched off under some conditions, such as coldness, surprise, and anger and is switched on again under other conditions, such as warming, relaxation, and mild exercise. In other words, capillary vessels perform two functions: switching flow on and off. It is speculated that the switch-off function is necessary to direct energy production to the glycolysis pathway, while the switch-on function is necessary for the mitochondrial pathway. This is because glycolysis takes place under anaerobic conditions, while oxidative phosphorylation in the mitochondria proceeds under aerobic conditions in the body. To switch off circulation, the negative electric charges on the surface of erythrocytes and the capillary wall may be decreased by stimulation of the sympathetic nerves and secretion of steroid hormones. Negative charge usually acts as repulsive force between erythrocytes and between erythrocytes and the capillary wall. By decreasing the negative charge, erythrocytes can aggregate and also adhere to the capillary wall. These behaviors may be related to the capillary flow switch-off function. Here, it is emphasized that the capillary vessels possess not only a switch-on function but also a switch-off function for circulation.