Questions: Name: John, a 75-year-old man, was diagnosed with osteoarthritis in his knee five years ago. Recently his condition worsened and so decided to see a doctor. John's doctor ordered a radiograph imaging in order to visualize his knee joint. a. What is osteoarthritis? What symptoms will John experience? (3 points) b. What type of joint is the knee? (1 point) c. What is the meniscus in the knee and state its function? (2 points) d. What is the role of articular cartilage in a synovial joint? (2 points)

a. What is osteoarthritis? What symptoms will John experience? (3 points)

Osteoarthritis is a degenerative joint disease characterized by the breakdown of cartilage, the tissue that cushions the ends of bones within joints. This condition leads to pain, swelling, and reduced motion in the affected joints. Over time, the cartilage wears away, causing bones to rub against each other, which can result in joint damage and further pain.

Symptoms that John may experience include:

• Joint pain, especially during or after movement
• Stiffness, particularly in the morning or after periods of inactivity
• Swelling around the joint
• Decreased flexibility and range of motion
• A grating sensation or sound when the joint is used
• Bone spurs, which are extra bits of bone that may form around the affected joint

b. What type of joint is the knee? (1 point)

The knee is a hinge joint. It primarily allows for flexion and extension, but it also permits a small degree of rotation and lateral movement.

c. What is the meniscus in the knee and state its function? (2 points)

The meniscus is a C-shaped piece of cartilage located in the knee joint. There are two menisci in each knee: the medial meniscus (on the inner side) and the lateral meniscus (on the outer side). The primary functions of the meniscus are:

• To act as a shock absorber, distributing the load across the knee joint and reducing the impact on the bones
• To stabilize the knee by evenly distributing the weight and improving the fit between the femur (thigh bone) and the tibia (shin bone)
• To aid in joint lubrication and nutrition by facilitating the movement of synovial fluid

d. What is the role of articular cartilage in a synovial joint? (2 points)

Articular cartilage is a smooth, white tissue that covers the ends of bones where they come together to form joints. In a synovial joint, the role of articular cartilage includes:

• Reducing friction between the articulating bones during movement, allowing for smooth and pain-free motion
• Absorbing shock and distributing loads across the joint, which helps to protect the underlying bone from damage
• Providing a low-friction surface that facilitates the movement of the joint and contributes to its overall stability and function

In summary, osteoarthritis is a degenerative joint disease that causes pain, stiffness, and reduced motion due to the breakdown of cartilage. The knee is a hinge joint, and the meniscus serves as a shock absorber and stabilizer. Articular cartilage reduces friction and absorbs shock in synovial joints.