But several factors work to curtail the hunger instinct, such as the presence of food in the digestive tract, or the flow of nutrients in the blood.
但是有很多种因素可以减缓这种饥饿本能，如消化道中的食物，或者血液中的营养物质。
2
Inversions can help clear the upper respiratory tract and drain secretions from the nose, allowing freshly oxygenated blood to flow into the oral cavity.
倒置体式能清理上呼吸道，排出鼻腔内的分泌物，让新鲜富氧的血液循环到口腔。
3
Closure at some point in the vocal tract that blocks the flow of air in the production of an oral or a nasal stop.