Cartilage as the cricoid cartilage and carina. Cartilage is composed of specialized cells called chondrocytes that produce a large amount of collagenous extracellular matrix, abundant ground substance that is rich in proteoglycan and elastin fibers. Cartilage is classified in three types, "elastic cartilage", "hyaline cartilage" and "fibrocartilage", which differ in relative amounts of collagen and proteoglycan. Cartilage does not contain blood vessels (it is avascular) or nerves (it is aneural). Nutrition is supplied to the chondrocytes by diffusion. The compression of the articular cartilage or flexion of the elastic cartilage generates fluid flow, which assists diffusion of nutrients to the chondrocytes.
Cartilage conduction cartilage conduction. In cartilage conduction, sound (vibration) energy stimulates the cartilages of the external auditory canal and induces air vibration. This air vibration can be then transmitted into the inner ear via the eardrum and middle ear, which in turn activates the cochlear nerve. Air vibration created from cartilage conduction is combined with sound from air conduction at the ear canal, and thus an amplified sound is perceived. This same phenomenon can be experienced when a telephone receiver is pressed against one’s ear when it is difficult to hear the person on the other end of the call. 1) Hearing