PHYSIOLOGY
SKELETAL MUSCLE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
thin
|
|
|
thick
|
|
|
Either A or B
|
|
|
None of the above
|
Detailed explanation-1: -Most of the cytoplasm consists of myofibrils, which are cylindrical bundles of two types of filaments: thick filaments of myosin (about 15 nm in diameter) and thin filaments of actin (about 7 nm in diameter).
Detailed explanation-2: -An individual sarcomere contains many parallel actin (thin) and myosin (thick) filaments. The interaction of myosin and actin proteins is at the core of our current understanding of sarcomere shortening.
Detailed explanation-3: -Muscles contract via interaction between thick (myosin-containing) and thin (actin-containing) filaments in response to increased levels of calcium.
Detailed explanation-4: -Actin makes up the thin filaments of striated muscle cells, recently reviewed in (171). It contains two domains, small and large, and an ATP binding pocket located in the cleft of the two domains (268).