question_answer 45)

  The muscular tissue which function throughout the life continuously without fatigue is (a) skeletal muscle         (b) cardiac muscle            (c) smooth muscle           (d) voluntary muscle

Answer:

(b) Cardiac muscles show characteristics of both smooth and striated muscles. These muscles are striated, cylindrical, branched and involuntary in nature. In addition to the light and dark bands, these muscles show densely stained cross bands called intercalated dises. These act as impulse boosters. Cardiac muscles contract and relax rapidly. rhythmically and tirelessly throughout a lifetime, from early embryonic stage until death. Voluntary muscles are under our control and act accordingly to our need, e.g., skeletal muscles, Smooth muscles also known as striated, viscera! or involuntary muscles are found in walls of hollow tubular organs like alimentary canal, ducts of glands, urogenital ducts and blood vessels except heart. They show slow contractions but remain contracted for a long period of time.