Bursa (B)
Bursa (B): Anatomy, Function, and Clinical Significance
A bursa (B) is a small, fluid-filled sac located within the joints of the body, primarily found between bones, tendons, and muscles. These sacs are crucial for reducing friction and facilitating smooth movement by acting as cushions in areas of high friction.
Anatomy and Structure
Bursae are lined with a synovial membrane, which secretes synovial fluid. This fluid is viscous and lubricating, similar in consistency to a raw egg white, allowing for smooth movement between moving parts in joints123.
Function
The primary functions of bursae include:
- Reducing Friction: By providing a lubricating layer, bursae minimize the friction between bones, tendons, and muscles, enabling smooth and efficient movement.
- Cushioning: They absorb pressure and act as shock absorbers, protecting underlying tissues from impact and stress23.
Types of Bursae
Bursae can be classified based on their location:
- Subcutaneous Bursae: Located between the skin and underlying bone, such as the prepatellar bursa over the kneecap35.
- Submuscular Bursae: Situated between muscles and bones, like the trochanteric bursa at the hip35.
- Subtendinous Bursae: Found between tendons and bones, such as the subacromial bursa in the shoulder35.
- Adventitious Bursae: Form in response to repeated stress or friction, often seen over bony prominences like bunions5.
Clinical Significance
Bursae are susceptible to inflammation, known as bursitis, which can cause localized pain, swelling, and restricted movement. Commonly affected bursae include the subacromial, olecranon, and prepatellar bursae4. Treatment options for bursitis include rest, NSAIDs, and intrabursal steroid injections4.
Conclusion
Bursae play a vital role in maintaining joint health by reducing friction and absorbing pressure. Understanding their anatomy and function is essential for diagnosing and managing conditions like bursitis.
