MUSCLE PHYSIOLOGY

PHYSIOLOGY

MUSCLE STRUCTURE FUNCTION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Contractions are generated by
A
shortening of thick filaments
B
shortening of thin filaments
C
sliding of thin filaments past thick filaments
D
“accordian-like” folding of thick and thin filaments
Explanation: 

Detailed explanation-1: -Muscle contraction is driven by relative sliding between the thick and thin filaments, which in turn is driven by a cyclical interaction of the myosin heads with actin coupled to the hydrolysis of ATP.

Detailed explanation-2: -During contraction, the myosin heads extend from the thick filament surface and attach to actin in the thin filaments, causing the filaments to slide past each other in a cyclic, ATP-driven process.

Detailed explanation-3: -Muscle contraction occurs when sarcomeres shorten, as thick and thin filaments slide past each other, which is called the sliding filament model of muscle contraction. ATP provides the energy for cross-bridge formation and filament sliding.

Detailed explanation-4: -The sliding filament theory explains the process of muscle contraction during which the thin filaments slide over the thick filaments, which shortens the myofibril. Each muscle fibre has an alternate light and dark band, which contains a special contractile protein, called actin and myosin respectively.

Detailed explanation-5: -The sliding filament model describes the process used by muscles to contract. It is a cycle of repetitive events that causes actin and myosin myofilaments to slide over each other, contracting the sarcomere and generating tension in the muscle.

There is 1 question to complete.