Question

Which of the following muscles get into fatigue very early?
A. Skeletal muscles
B. Smooth muscles
C. Cardiac muscle
D. All the above

Answer 1

Hint: It is a connective tissue which is present in all the muscles as fascia. Epimysium is an enclosing muscle of the connective tissue. Each muscle fibre has a connective tissue called endomysium. The muscles that get fatigued easily are voluntary muscles.

Complete answer: The myofibrils are 1 micrometre in diameter and it is a long protein bundle that contains myofilaments. Myofibrils are composed of muscle fibres. Muscle fibres are joined together by multiple bundles of cells referred to as skeletal muscle. It exhibits a banding pattern that can be viewed under a microscope in the arrangement of cytoskeletal elements in the cytoplasm. Arrangement of muscle fibres on the axis is called muscle architecture. These muscles fatigue very early as compared to other muscles. These muscles can be voluntarily controlled and are attached to bones by bundles of collagen fibres known as tendons. The muscle of the heart is called cardiac muscles or myocardium. Cardiac muscle is different from skeletal muscle in terms of rhythmic contraction and cardiac muscle is involuntary and the skeletal muscle is voluntary. The cardiac muscle or myocardium lies between the epicardium and endocardium. Cardiac muscle is striated and its contractile unit is the sarcomere.
Hence, the correct answer is option A.

Note: Fascicles are arranged longitudinally, parallel in fusiform muscles that form the skeletal muscles. They run parallel on the axis and are surrounded by perimysium, which is a kind of connective tissue.