Myringotomy cleaning it with an ear spoon. Surprisingly, the patient's hearing improved. There are also reports from the 17th and 18th centuries describing separate experiments exploring the function of the ear drum. In particular, the animal experiments of Thomas Willis were expanded upon by Sir Astley Cooper, who presented two papers to the Royal Society in 1801 on his observations that myringotomy could improve hearing. First, he showed that two patients with perforations of both eardrums could hear perfectly well, despite conventional wisdom that this would result in deafness. Second, he demonstrated that deafness caused by obstruction of the Eustachian tube
Development of the human body and temporal changes in gene expression, cell growth and cellular differentiation. A nearly identical process occurs in other species, especially among chordates. A fetus is a stage in the human development considered to begin nine weeks after fertilization. In biological terms, however, prenatal development is a continuum, with many defining feature distinguishing an embryo from a fetus. A fetus is also characterized by the presence of all the major body organs, though they will not yet be fully developed and functional and some not yet situated in their final location. The fetus and embryo develop within the uterus, an organ