MEDICAL PHYSIOLOGY

PHYSIOLOGY

SYNAPTIC PHYSIOLOGY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
what is the meaning of the sarcomere?
A
the basic contractile unit of muscle fiber
B
a synaptic connection between the terminal end of a motor nerve and a muscle
C
a single cylindrical muscle cell
D
the rapid communication between electrical events occurring in the plasma membrane of skeletal muscle fibres
Explanation: 

Detailed explanation-1: -A sarcomere is the basic contractile unit of a myocyte (muscle fibre). A sarcomere is composed of two main protein filaments (thin actin and thick myosin filaments) which are the active structures responsible for muscular contraction.

Detailed explanation-2: -A sarcomere is the basic contractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments-actin and myosin-which are the active structures responsible for muscular contraction. The most popular model that describes muscular contraction is called the sliding filament theory.

Detailed explanation-3: -The fundamental repeat unit within muscle that is responsible for contraction is the sarcomere. The sarcomere consists of a bundle of myosin-containing thick filaments flanked and interdigitated with bundles of actin-containing thin filaments (Fig. 1).

Detailed explanation-4: -By studying sarcomeres, the basic unit controlling changes in muscle length, scientists proposed the sliding filament theory to explain the molecular mechanisms behind muscle contraction. Within the sarcomere, myosin slides along actin to contract the muscle fiber in a process that requires ATP.

Detailed explanation-5: -To say that the sarcomere is the functional unit means that all the components needed for contraction are contained within each sarcomere. In fact, muscle is composed of millions of tiny sarcomeres, and each sarcomere shortens, thus resulting in muscular contraction.

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