Question

Describe the engineering explanation behind the following structural/anatomical

features as related to bone, articular cartilage, tendons and ligaments. Please use

precise and concise answers.

Tendons and Ligaments

1. The difference in fiber arrangement between tendons and ligaments

2. The insertion of ligament into bone

3. The use of a special brace for a child with club foot

4. The 2:1 elastin to collagen ratio in the ligamentum flavum

5. The abnormal motion in a knee with an Anterior Cruciate Ligament (ACL)

injury

Answer 1

STRUCTURAL AND ANATOMICAL FEATURES OF BONE:

Bone (osseous) tissue is the structural and supportive connective tissue of the body that forms the rigid part of the bones that make up the skeleton. Overall, the bones of the body are an organ made up of bone tissue, bone marrow, blood vessels, epithelium, and nerves.The bones of the body come in a variety of sizes and shapes. The four principal types of bones are long, short, flat and irregular. Bones that are longer than they are wide are called long bones.

It also consists of

• osteoblasts and osteocytes, responsible for creating bone.
• osteoclasts or bone resorbing cells.
• osteoid, a mix of collagen and other proteins.
• inorganic mineral salts within the matrix.
• nerves and blood vessels.
• bone marrow.
• cartilage.
• membranes, including the endosteum and periosteum.

ARTICULAR CARTILAGE:

Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints. Healthy cartilage in our joints makes it easier to move. It allows the bones to glide over each other with very little friction.

TENDONS AND LIGAMENTS:

A tendon is a fibrous connective tissue which attaches muscle to bone. Tendons may also attach muscles to structures such as the eyeball. A ligament is a fibrous connective tissue which attaches bone to bone, and usually serves to hold structures together and keep them stable.

1)DIFFERENCE IN FIBER ARRANGEMENT:

In tendons, fibers are present as compact parallel bundles, whereas in ligaments fibers are compactly packed and not arranged in parallel bundles. Even the fibroblast in tendons are in continuous row form, but in ligaments, tendons are scattered.

2) INSERTION OF LIGAMENT INTO THE BONE:

At fibrous entheses, the tendon or ligament attaches either directly to the bone or indirectly to it via the periosteum. In both cases, dense fibrous connective tissue connects the tendon/ligament to the periosteum and there is no evidence of (fibro)cartilage differentiation

3) USE OF SPECIAL BRACE:

A clubfoot brace (often just called an orthotic) has two parts: a bar (usually metal) and special shoes (or boots) that attach at each end. The brace keeps the "fixed" clubfoot (or feet) in the corrected position so it doesn't twist back to where it was before the casting phase.

4) ELASTIN TO COLLAGEN RATIO

The ligamentum flavum is composed of elastin and collagen fibers in a 2:1 ratio. The elastin fibers provide elasticity to the ligament, while the collagen fibers provide stiffness and stability. With age, the elastin to collagen ratio decreases, and this causes decreased elasticity and increased stiffness or fibrosis.

5) ACL INJURY

Most people who tear their ACL feel pain and a "pop" in their knee when the injury happens. Their knee usually gets swollen soon after the injury. After the swelling goes down, someone with an ACL tear usually can walk. But the knee may feel unstable and can "give way" and make the person stumble or fall.