Muscle Tendon Junction Structure and Function

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What is the main cause of muscle atrophy and potential failure at the myotendinous junction?

Lack of synovial fluid in tendons

Inflammation of the paratenon

Presence of a tendon sheath

Increased stress at the junction (correct)

What is the function of a tendon sheath in relation to tendons?

Directs the path of the tendon and produces synovial fluid for gliding and nutrition (correct)

Causes inflammation in the paratenon

Surrounds tendons without any noticeable function

Composed of loose fibrillar tissue for free tendon movement

What characterizes peritendinitis?

Allows free movement of the tendon against surrounding tissue

Presence of crepitus along with discomfort (correct)

Inflammation of true tendon sheaths

Composed of loose fibrillar tissue

What does the term 'bimodal vs unimodal fibril density' refer to in tendons?

The percentage of large and small fibrils within the tendon Signup and view all the answers

What is the difference between bimodal and unimodal fibril density in tendons?

Bimodal has both large and small fibrils, unimodal has only large fibrils Signup and view all the answers

What is a common characteristic of paratenon in relation to tendon sheaths?

'Composed of loose fibrillar tissue' Signup and view all the answers

'Crepitus' is a term used to describe:

'A palpable or audible grating or crunching sensation produced by motion' Signup and view all the answers

What does the mechanical theory propose about the development of tendinopathy?

Progressive cell death results from impaired tendon repair Signup and view all the answers

What role do tenocytes play in the development of degenerative changes in tendons according to the mechanical theory?

They trigger degenerative changes in tendons Signup and view all the answers

What type of molecules are tendons fixed to skeletal muscle fibers by?

Adhesion molecules such as fibronectin Signup and view all the answers

What does the dynamic function of the muscle-tendon junction (MTJ) folding structure do?

Increases the angle of force transmission Signup and view all the answers

What happens to the MTJ during slow, heavy movements?

Shear forces create sliding of collagen and cross-link tearing Signup and view all the answers

How does the MTJ respond to fast movements?

The tendon acts like a sheet and no collagen fiber cross-link tearing occurs Signup and view all the answers

What happens to the tendon finger-like projections into the muscle with muscle atrophy?

They decrease in complexity and density Signup and view all the answers

Where does mechanical failure of the muscle-tendon junction occur in atrophied cells?

Just external to the junctional plasma membrane Signup and view all the answers

What type of stress is a high proportion of force transmitted through at the MTJ?

Shear stress Signup and view all the answers

What is the most frequent site of spontaneous rupture of the tibialis anterior tendon?

The avascular zone Signup and view all the answers

Which of the following is considered an intrinsic risk factor for tendon injuries?

Obesity Signup and view all the answers

What is the definition of tendinopathy provided in the text?

Persistent tendon pain and loss of function related to mechanical loading Signup and view all the answers

What has been suggested to mediate the adaptive responses of tendons to mechanical overload?

Neurogenic inflammation Signup and view all the answers

What does the passage suggest about the relationship between inflammation and tissue degeneration in the pathogenesis of Tendinopathy?

They work together in the pathogenic cascade Signup and view all the answers

What is the first stage of the continuum model of tendon pathology?

Reactive tendinopathy Signup and view all the answers

What are the two phases of tendon change described in the passage?

Asymptomatic and symptomatic Signup and view all the answers

What is the role of tendon collagen turnover in the pathogenesis of Tendinopathy according to the passage?

It is a key component of the continuum model Signup and view all the answers