Why do I feel dizzy when spinning in circles

Turning in circles is a manifestation of people's coordination ability. People who can turn in circles normally have well-developed and healthy brains and are not prone to diseases. However, some people are prone to dizziness when turning in circles, which may be a sign of health problems. Therefore, people with this symptom must pay more attention. Let’s take a look at why turning in circles causes dizziness? I hope everyone can understand it.

There is a balance device in the human ear called the semicircular canals. The semicircular canals are composed of three mutually perpendicular small rings and are responsible for the three-dimensional sense of balance in the head.

When there is a problem with the semicircular canals, symptoms of vertigo may occur.

The semicircular canals can provide information about the head's orientation (tilt) in relation to gravity, and are also excited by linear acceleration (deceleration) motion. When the head is in a normal position, there is a certain pressure relationship between the otoliths and the hair cells. When the position of the head changes, the relative positions of the two in space also change, and the otoliths pull the cilia of the hair cells to varying degrees, thereby stimulating the hair cells. After the hair cells are excited, impulses are transmitted to the vestibular nucleus through the vestibular nerve, reflexively causing changes in muscle tension and maintaining body balance. The appropriate stimulus for the semicircular canals is rotational acceleration. When the head rotates, the endolymph shifts in the opposite direction of rotation due to inertia, and the terminal cap bends and deforms accordingly, which indirectly stimulates the hair cells and the vestibular nerve endings at their base.

Electrophysiological studies have shown that when the head is in a resting position, the nerve endings in the terminal cap emit certain impulses. When the terminal cap is displaced to one side, that is, when the horizontal duct lymph flows into the ampulla and the vertical duct lymph flows out of the ampulla, causing the terminal cap to bend, the impulse discharge increases; when it shifts in the opposite direction, the discharge decreases. When the rotation continues at a constant speed, the release at the beginning is the same as when it is accelerated, and then gradually returns to the original level. When the rotation stops suddenly, the terminal cap is also displaced, but in the opposite direction to the beginning. Although endolymph displacement stops within 3 seconds, it takes 25 to 30 seconds for the terminal cap to return to a resting state. At this time, people will have a feeling of rotating in the opposite direction.