Identify the correct description of the different types of bones:
View Available Hint(s) for Part B
Compact bone is made of trabeculae and is denser than spongy bone.
Compact bone provides support at areas where stress occurs.
Spongy bone is made of trabeculae and is lighter than compact bone.
Spongy bone is made of osteons and is less dense than compact bone.
Spongy bone is structurally stronger than compact bone.
The Correct Answer and Explanation is:
Correct Answer:
Spongy bone is made of trabeculae and is lighter than compact bone.
Explanation
The human skeleton is composed of two main types of bone tissue: compact bone and spongy bone, each with distinct structures and functions.
Spongy bone, also known as cancellous or trabecular bone, is characterized by a porous, lattice-like structure composed of thin plates called trabeculae. These trabeculae are oriented along lines of stress to provide strength while minimizing weight. Between the trabeculae are spaces filled with bone marrow, which aids in the production of blood cells and storage of fat. This architectural design makes spongy bone lighter than compact bone, reducing the overall weight of the skeleton and allowing for easier movement. It is typically found at the ends of long bones, in the pelvis, ribs, skull, and the vertebrae.
In contrast, compact bone (or cortical bone) is denser and stronger. It is composed of tightly packed structural units called osteons or Haversian systems, which consist of concentric rings (lamellae) around a central canal containing blood vessels and nerves. This dense arrangement enables compact bone to provide strength and resistance to bending and torsion, especially in areas subjected to high stress, such as the shafts of long bones.
Incorrect statements include:
- Saying compact bone is made of trabeculae (it is not; that’s spongy bone),
- Claiming spongy bone is made of osteons (osteons are in compact bone),
- Suggesting spongy bone is structurally stronger than compact bone (compact bone is denser and structurally stronger),
- And the overly broad claim that compact bone provides support where stress occurs, without clarifying that spongy bone also plays a role by aligning trabeculae along stress lines.
Thus, the accurate description is that spongy bone is made of trabeculae and is lighter than compact bone
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