The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts:
In a laboratory setting, HIV has been kept alive for as long as 15 days after the body fluid has dried, but this was controlled at a stable temperature and humidity that would be nearly impossible to reproduce in the natural world.
One reason why HIV transmission may be less likely in healthy women is due to the acidity of vaginal secretions. HIV may survive in dried blood at room temperature for up to five or six days provided that the optimum pH level is maintained; drying of blood does not seem to affect the infectivity of HIV.