Musculoskeletal Flashcards
Covering of muscles?
Endomysium, Perimysium and Epimysium
Perimysium?
Connective tissue that wraps bundles of muscle fibers. (The Bundles) as know as fascicles.
Endomysium
Connective tissue that wraps each individual muscle fiber.
Epimysium
Connective tissue that wraps the whole muscle (Appears echogenic)
Insertion
The portion of the muscle that attaches to the middle bone
Origin
The part of the muscle attached to stationary bone.
Pennate
Muscle fibers run parallel to the bone making a fan shape pattern.
What is the structure of the MLC?
Three-layer structure with superficial and deep layers separated by a hypoechoic layer
Loose connective tissue forms the middle layer providing potential space for bursae in some individuals.
What does the Medial Collateral Ligament (MCL) connect?
Connects the medial femoral condyle to medial proximal tibia
MCL is also known as the Tibial collateral ligament.
What is the typical thickness of ligaments?
Typically measure between 2 – 3 mm in thickness (AP)
What are ligaments?
Short bands of tough fibers that connect bones to other bones
What is the function of ligaments?
Support and strength of joint, allowing joint flexibility and limiting movement to protect joints from hyper-extension or hyper-flexion
What is a bursa?
Saclike structure surrounding joints and tendons that contains synovial fluid
What are the two types of bursae based on their relationship to the joint space?
- Communicating Bursa
- Non-communicating Bursa
What is the appearance of bursae on ultrasound imaging?
Bursae appear hypoechoic due to synovial fluid but are difficult to see due to very small size
What happens to a bursa during inflammation?
Leads to accumulation of fluid, increasing size and may become more echogenic, similar to a complex cyst
What is considered abnormal for a bursa size?
Bursa larger than 2 mm in any dimension
What is the purpose of synovial fluid?
Helps to prevent friction between musculoskeletal structures, such as tendon and bone or ligament and bone
What are the indications for musculoskeletal ultrasound evaluation?
- Trauma to ankle with possible Achilles tendon tear
- Painful shoulder with inability to lift the arm normally (to exclude rotator cuff tear)
- Soft tissue mass to define extent and structures involved
- Swollen, red, tender limb or joint with possible abscess or osteomyelitis
- Abrupt onset of lower leg pain with possible deep venous thrombosis or Baker’s cyst
- Masses - Soft Tissue or Bone Tumors
What is the appearance of nerves on ultrasound?
Mixed echogenic appearance, appearing hyperechoic compared to muscle tissue but hypoechoic compared with tendons
What is a Baker’s cyst?
Related to a communicating bursa located in the medial popliteal fossa
What is the definition of enthesis?
Junction of tendon to bone occurring via a narrow band of fibro-cartilage
What is the epimysium?
Outer layer of fibrous connective tissue encasing the entire muscle fibers, muscle bundles, blood vessels, lymphatic system, and nerve fibers
What are the parts of skeletal muscles?
- Muscle Fibers
- Perimysium
- Epimysium
