ABSTRACT
1 REFLEX, an involuntary response to a stimulus which passes through the lower spinal and nerve centers without conscious action by the brain. The most common automatic reflexes are swallowing chewed food, laughing in response to tickling, jumping out of the path of danger, sneezing when the nose is irritated, coughing on inhalation of tobacco smoke, scratching in reponse to itching; erection of the penis and ejaculation in sexual excitement and intercourse; and the startle reflex on hearing a sudden loud noise …
