The breathing movement of human body and higher animals can be carried out continuously and rhythmically because of the existence of internal regulation mechanism. All kinds of stimuli in and out of the body can directly act on the receptors in the center or different parts, and affect respiratory movement reflexively to meet the needs of metabolism of the body and increase the influence of ineffective cavity on respiratory movement.
Experimental method:
Incise the xiphoid skin at the lower sternum, and then make an incision about 2ml long along the abdominal white line. Carefully separate the surface tissue (don't hurt the sternum) to expose the xiphoid process and the bone stalk, and cut off the bone stalk of a xiphoid cartilage with a golden crown to completely separate the xiphoid cartilage from the sternum, but the diaphragm attached to it must be kept intact. At this time, the movement of diaphragm can affect xiphoid cartilage.
In acute animal experiments, there are three ways to record respiratory movement. One method is to record the respiratory movement by connecting the pressure sensor with the tracheal intubation. The other is to record through a breathing belt tied to the chest and equipped with a pressure sensor; The third is to record the movement of the diaphragm through a tension sensor. First, anesthetize animals, perform cervical trachea, insert tracheal intubation, separate/kloc-0 common carotid artery and 2 vagus nerves, and thread for later use.