Crying is a complex human response that goes far beyond the simple shedding of tears. It encompasses a range of physiological actions, involving numerous muscles throughout the face, throat, and chest. Its visible and audible components, from facial expressions to sobbing, result from many muscles working in concert, showcasing intricate physical mechanisms.
Facial Muscles in Crying
The visual aspect of crying relies on specific facial muscles that create characteristic expressions and facilitate tear flow. The orbicularis oculi muscle, encircling the eyes, allows tight eye closure and squinting. This action spreads tears across the eyeball, keeping it moist and aiding drainage through the lacrimal system. Its contraction also visibly tightens the area around the eyes during emotional distress.
The corrugator supercilii, located between the eyebrows, pulls them downward and inward, creating vertical “frowning” wrinkles associated with sadness. This muscle works with the orbicularis oculi to produce the furrowed brow. The depressor anguli oris muscle pulls the mouth corners downward and laterally, contributing to the downturned mouth shape that conveys sadness or disapproval.
The platysma, a broad sheet-like muscle extending from the chest up into the lower face and neck, contributes to crying expressions. It can pull the skin around the lower part of the mouth down or out, creating creases in the lower face and neck. Its contraction can cause a quivering chin or a general pulling down of the lower face during intense crying.
Muscles for Breathing and Sound
Crying involves auditory components like sobbing, gasping, and wailing, generated by respiratory and laryngeal muscles. The diaphragm, separating the chest from the abdomen, and the intercostal muscles between the ribs, are essential for breathing. During crying, these muscles cause irregular breathing patterns and gasps through involuntary contractions and disrupted rhythm.
The diaphragm contracts downward during inhalation, expanding the lungs, and relaxes upward, expelling air. In crying, this normal rhythm is disturbed, leading to the characteristic “stutter breath” or sobbing pattern as the diaphragm attempts to regain control. The intercostal muscles assist in elevating and depressing the ribs, influencing chest volume during these irregular breathing efforts.
The muscles of the larynx, or voice box, control the vocal cords and produce the sounds associated with crying. These intrinsic laryngeal muscles adjust the tension and length of the vocal folds, and the space between them. This precise control allows for a range of sounds, from soft whimpers to loud wails or screams, by modulating airflow and vocal cord vibration.
The Coordinated Muscular Effort
The complete crying response, integrating facial expressions with breathing and vocalizations, requires intricate coordination of these diverse muscle groups. This orchestration is managed by the nervous system, with specific brain regions playing a central role in initiating and regulating these complex muscular actions. The limbic system is a network of structures deep within the brain that processes and manages emotions.
Within the limbic system, the hypothalamus regulates autonomic functions, including those related to emotional responses such as changes in heart rate, blood pressure, and breathing. The amygdala, another limbic structure, processes emotional information and coordinates emotional responses. These brain regions work together to translate emotional states into the widespread physiological and muscular actions observed during crying.
Crying is not merely a simple reflex but an intricately coordinated physiological event. The brain’s ability to integrate signals from emotional centers with motor control pathways ensures that facial muscles, respiratory muscles, and laryngeal muscles act in concert. This coordinated effort results in the holistic expression of crying, where the visual signs and audible sounds combine to convey emotional distress. Different types of crying, whether emotional or reflexive, involve similar muscle groups but are triggered and modulated uniquely by the brain’s complex control systems.