Stilts are poles with stirrup-like projections for the feet placed at some distance from the bottom and used for walking over rough ground. They were used for crossing rivers, scaling castle walls and as a diversion. Research Stilts
The auditory ossicles (the incus, malleus, and stapes) are the bones of the middle ear. The incus is shaped like an anvil. The malleus is shaped like a hammer and the stapes is shaped like a stirrup. They are the smallest bones in the human body. The three bones are connected to each other by hinges and act as mechanical levers to carry and push the vibrations of the ear drum forward to the flexible membrane of the oval window. When sound waves cause the tympanic membrane to vibrate, the vibrations move the malleus, which in turn moves the incus. The incus moves the stapes which is attached to the oval window. The sound is then passed to the inner ear. The leverage of the middle ear bones increases the intensity of the sound wave by five decibels before the wave is funneled toward the oval window. Research Auditory Ossicles
The ear is the organ used for hearing. It converts sound into electrical impulses that are fed to the brain. The external ear is composed of the auricle (the pinna), and the auditory canal (the meatus auditorius externus). The Pinna or auricle surrounds the entrance to the auditory canal. It consists of cartilage covered by skin, with small muscles connecting it to the scalp. At the base of the ear is a fleshy lobe. The meatus auditorius is a canal about three centimeters long in the adult, partly bony and partly cartilaginous, leading from the pinna of the ear to the drum. The lining cells secrete the waxy substance found in the canal. In young children the canal is much shorter. The ear drum (tympanic membrane) is a thin oval-shaped membrane, inserted into a groove around the auditory canal. Normally it is white, glistening and somewhat transparent, so that some of the structures of the middle ear are partly visible when viewed through an auroscope. It separates the auditory canal from the middle ear.
The Tympanum or middle ear is a cavity within the temporal bone. It contains several important structures, including three small bones which connect the drum with the internal ear; they are the malleus or hammer, the incus or anvil, and the stapes or stirrupbone. They transmit the vibrations of sound waves to the inner ear. The Eustachian Tube is a channel of communication between the tympanum and the upper part of the pharynx. It admits air from the throat to the tympanum and so maintains an equal pressure on both sides of the drum. The Labyrinth or internal ear is a series of chambers through the petrous bone, comprising the vestibule, a three-cornered cavity within the tympanum; the semicircular canals communicating with the vestibule; and the cochlea, which makes two and a half turns around an axis called the modiolus. The human ear is capable of detecting sounds in the frequency range 20 hz to 20 khz, approximately. Research Ear
In architecture a bridle iron is a strong flat bar of iron, so bent as to provide support, as in a stirrup, one end of a floor timber, etc., where no sufficient bearing can be had. Research Bridle Iron
Abbreviations
Research Stilts
