What is the gag reflex? What functions does this reflex perform in humans and what are its physiological mechanisms? The gag reflex belongs to the group of unconditioned reflexes. Accompanies reflexes of breathing, food, bladder and nervous regulation of a person and represents an impulse through the vagus nerve, causing contraction of the muscles of the epigastrium and diaphragm; then the voluntary parasympathetic impulse is primary and the nerve impulse is secondary. In humans, the reflex can be congenital and acquired. An acquired gag reflex is formed from frequent infectious diseases, most often due to poisoning. All functions associated with vomiting reflexes in a healthy person are determined by will, not instinct. Strengthening any of these reflexes creates the need for processing. The relaxation reflex is no less interesting - this is the second group of reflexes presented in the headings of motor acts; it is associated with ensuring tone within the muscle fibers, ensuring the retention of already formed food products.