Final answer:
Long bones in humans and animals are characterized by an elongated shaft called the diaphysis and rounded ends termed epiphyses, primarily made of compact and spongy bone respectively. These bones function as levers facilitating movement. Differences in bone structure between species reflect adaptations to particular functions.
Step-by-step explanation:
Characteristics of Long Bones in Humans vs Animals
A characteristic of a long bone in both humans and animals is that they have a shaft known as the diaphysis, which is much longer than it is wide. This cylindrical structure is predominantly made up of dense and hard compact bone. The ends of these bones are referred to as the epiphyses, which are round, contain spongy bone, and are usually covered in articular cartilage. Long bones exhibit a medullary cavity that stores bone marrow, and in adults, this cavity is filled with yellow marrow. In a growing bone, each epiphysis meets the diaphysis at the metaphysis, a narrow area containing the epiphyseal plate, essentially a growth plate made of hyaline cartilage. When growth ceases, this plate ossifies into an epiphyseal line.While the basic structure of long bones is similar in humans and animals, there might be variations in size, shape, and proportion to accommodate different functions. For instance, the bone structure in the leg of a cat has similarities to that in the human arm, yet the function of the limbs can be notably different, reflecting the adaptive requirements of different species.Long bones play a fundamental role in movement by acting as levers that move under muscle contraction. They include key bones in the limbs such as the humerus, ulna, radius, femur, tibia, and fibula, and also extend to the bones of the fingers and toes.