Nascent Pharynx, Physiology, Reflexes

The pharynx must maintain and coordinate the safety of airway and digestive functions regardless of maturational state or aging, activity or sleep state, postural variability, health, or illness. Life-threatening events are frequent in early stages of life, varying from apnea to laryngospasm to airway aspiration and may be the result of malfunction of pharyngeal–airway communications. Similarly, feeding and swallowing problems are also frequent in neonatal period, and dysphagia may result from malfunction of pharyngeal–esophageal communications. Hence, understanding the developmental physiology of deglutition and pharyngeal phase of swallowing is vital to the study of dysphagia in young infants. Unfortunately, not much is known about nascent human pharynx either during fetal life or in those born prematurely. Much of the knowledge is gleaned from animal studies or adult human studies. In this chapter, we attempt to elucidate what is known and relevant to the nascent pharyngeal anatomy and functions.