There aren’t many situations that can make me cry. So, imagine my surprise when I completely lost it during a certain death scene in Harry Potter and Deathly Hallows. Before the embarrassing tears started really flowing, I felt a lump in my throat. Many of us who cry or are on the verge of crying often feel the same lump-like sensation. As there isn’t an actual lump forming in our throat, where does the sensation come from? The answer may lie in the autonomic nervous system.
Crying comes with a range of different effects, including an increase in heart rate, some sweating, and sometimes a lump-like sensation in the throat. The lump that forms could be linked with how our body responds to stressful situations. Professor Ad Vingerhoets, a clinical psychologist at Tilburg University, tells IFLScience that when we get anxious or fearful, we enter the “fight or flight” mode.
“This means that our body gets prepared for action by increasing the activity of the sympathetic nervous system. This is the part of the autonomic nervous system that controls most of our bodily functions,” Vingerhoets explains.
During these stressful situations, our heart rate increases, blood pressure rises and blood is redistributed from the intestines to the muscles, Vingerhoets says. In addition, our respiration rate also increases.
“The faster rate of respiration impacts the muscle that controls the opening of the throat called the glottis (middle of the larynx). The glottis expands to allow more air in during the preparation for fight or flight,” Vingerhoets tells IFLScience.
There are two explanations for what happens next. According to the first, it’s the expansion of the glottis that creates the well-known lump-like sensation. More specifically, swallowing involves closing the glottis and when we try to swallow we work against the muscles that open the glottis in response to crying. It’s this resulting muscle tension that could be giving us lump-like sensation in our throat.
“The second explanation puts more emphasis on the attempts to avoid shedding tears which is accompanied by stopping breathing and thus constricting the muscle in our throat. This also results in a battle between these opposing forces to expand and contract the glottis at the same time, hence causing the ‘tightness’ we feel in our throat,” Vingerhoets says.
Research on why we cry has a long and complicated history. Charles Darwin described crying as an “incidental result, as purposeless as the secretion of tears from a blow outside the eye,” but the evolutionary role for crying is still being hotly debated. Many researchers argue that Darwin was wrong and suggest that the capacity for tears gave early hominids an adaptive advantage as crying could be “a social signal” that evolved from mammalian distress calls.