Sinus Anatomy. INTRODUCTION. The paranasal sinuses (âthe sinusesâ) are air-filled cavities located within the bones of the face and around the nasal cavity and eyes. Each sinus is named for the bone in which it is located: Physiology.The pink membranes lining the sinuses make mucus that is cleared out of the sinus cavities and drains into the nasal passage. The right and left nasal passages are separated in the middle by a vertical plate of cartilage and bone called the nasal septum (figures 1 and 2).ach sinus is named for the bone in which it is located: Physiology. The pink membranes lining the sinuses make mucus that is cleared out of the sinus cavities and drains into the nasal passage.
[freÂ´kwen-se] 1. the number of occurrences of a periodic or recurrent process in a unit of time, such as the number of electrical cycles per second measured in hertz. In cardiac pacing terminology, frequency is expressed by the formula: frequency = Â½ Ã pulse width.
An audio frequency (abbreviation: AF) or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human. The SI unit of audio frequency is the hertz (Hz). It is the property of sound that most determines pitch. The generally accepted standard range of audible frequencies is 20 to 20,000 Hz, although the range of frequencies individuals hear is greatly influenced by environmental factors. Frequencies below 20 Hz are generally felt rather than heard, assuming the amplitude of the vibration is great enough.