Acoustic reflex contraction of the stapedius muscle stiffens the middle-ear, thus decreasing middle-ear admittance; this can be measured thanks to tympanometry. The acoustic stapedius reflex can also be recorded by means of extratympanic manometry (ETM). As the stapedius muscle is innervated by the facial nerve, a measurement of the reflex can be used to locate the injury on the nerve. If the injury is distal to the stapedius muscle, the reflex is still functional. A measurement of the reflex can also be used to suggest a retrocochlear lesion (e.g., vestibular schwannoma, acoustic neuroma). The acoustic reflex normally occurs only at relatively high
Development of the human body inconsistent and contradictory; a person may be biologically an adult, and have adult behavior but still be treated as a child if they are under the legal age of majority. Conversely, one may legally be an adult but possess none of the maturity and responsibility that may define an adult. Development of human organs and organ systems begins in the embryo and continues throughout the human lifespan. Development of the human body Human development is the process of growth to maturity. The process begins with fertilisation, where an egg released from the ovary of a female is penetrated by a