Long bones

Definition

Long bones are a type of bone characterized by their elongated shape and are primarily found in the limbs. They are crucial for facilitating movement and supporting the weight of the body, as they act as levers during physical activities. Each long bone consists of a diaphysis, or shaft, which is surrounded by a layer of compact bone, and two ends called epiphyses that are typically made up of spongy bone.

5 Must Know Facts For Your Next Test

1. Long bones are primarily found in the arms and legs, including the femur, tibia, fibula, humerus, radius, and ulna.
2. They play a vital role in movement as they provide structure and leverage, allowing for greater mobility.
3. Long bones contain both compact bone on the outside for strength and spongy bone on the inside for flexibility and shock absorption.
4. Growth plates, or epiphyseal plates, located at the ends of long bones allow for growth in length during childhood and adolescence.
5. In adults, long bones contribute to the storage of minerals, such as calcium and phosphorus, which are vital for various bodily functions.

Review Questions

• How do long bones contribute to overall human movement and stability?
  • Long bones serve as levers that facilitate movement by providing structure and support to the body's limbs. They enable muscles to exert force on them, allowing for a wide range of movements such as walking, running, and jumping. Their elongated shape maximizes mechanical advantage, which helps maintain stability while bearing weight during various activities.
• Discuss the differences between the diaphysis and epiphysis in long bones and their respective functions.
  • The diaphysis is the elongated shaft of a long bone that provides strength and houses the medullary cavity filled with bone marrow. In contrast, the epiphysis refers to the rounded ends of long bones that articulate with other bones at joints. The epiphysis is essential for joint movement due to its spongy structure, which allows for flexibility and shock absorption during physical activity.
• Evaluate the importance of growth plates in long bones during childhood development and how they impact adult height.
  • Growth plates are critical during childhood development as they are areas of cartilage located at each end of long bones that allow for lengthening as a child grows. These plates produce new bone cells, leading to increased height until they eventually fuse and become solid bone in adulthood. The timing of this fusion influences final adult height, making growth plates an essential factor in determining an individual's stature over time.

Related terms

Diaphysis: The long central shaft of a long bone, providing strength and support while also containing the medullary cavity.

Epiphysis: The rounded ends of long bones, which articulate with other bones and contain spongy bone that aids in joint movement.

Medullary Cavity: The hollow space within the diaphysis of long bones that contains bone marrow, which is responsible for producing blood cells.