Cartilage in the outer ear is __.
elastic cartilage
hyaline cartilage
fibrocartilage
The correct answer and explanation is:
The correct answer is elastic cartilage.
Elastic cartilage is a type of cartilage that is highly flexible due to the presence of elastic fibers in its extracellular matrix. It provides support and flexibility, which is necessary for structures like the outer ear (auricle or pinna), the epiglottis, and the Eustachian tube. The elastic fibers give it the ability to bend and return to its original shape without losing its structure, making it ideal for areas that require flexibility and resilience.
Cartilage, in general, is a specialized connective tissue that lacks blood vessels and is composed of chondrocytes, the cells responsible for producing the extracellular matrix. The matrix consists of collagen fibers and ground substance, which vary in composition depending on the type of cartilage.
Hyaline cartilage is another type of cartilage, but it is more rigid than elastic cartilage and is found in areas such as the ribs, nose, larynx, and joints. It provides smooth surfaces for movement and is involved in reducing friction between bones.
Fibrocartilage, on the other hand, is tough and offers strength and resistance to compression. It is found in structures that are subjected to high mechanical stress, such as the intervertebral discs, pubic symphysis, and menisci of the knee. It has thick bundles of collagen fibers, which give it the ability to resist tension and absorb shock.
Therefore, the outer ear’s flexibility is due to elastic cartilage, which ensures that the ear can maintain its shape while being flexible enough to bend when necessary. This flexibility is essential for functions like capturing sound and adjusting to external forces.