Muscular and Skeletal system VSAQs.

Question 1

What is a “ motor unit “ with reference to muscle and nerve?

Answer 1

A motor neutron and the set of muscle fibers innervated by all the tele dendrites constitute a motor unit.

Question 2

What is traid system?

Answer 2

Sarcolemma of muscle fiber invaginates into the sarcoplasm and forms transverse tubules ( T-tubules). Each T-tubule is flanked on either side by the terminal cisternae of sarcoplasmic reticulum. A T-tubule and the two terminal cisternae at its sides form the triad system.

Question 3

Write the difference between actin and myosin?

Answer 3

Actin is one of the proteins that constitutes the thin filaments of a myofibrils. Myosin is also a protein that forms the thick filaments of a myofibrils.

Question 4

Distinguish between red muscle fibers (aerobic muscles) and white muscle (anaerobic muscles) fibers.

Answer 4

a) The muscle fibers containing a red pigment myoglobin are called red muscles fibers. Myoglobin stores oxygen and contains mitochondria.

b) The muscle fibers containing very little, or no myoglobin appears to be pale or white. Hence, they are called white muscle fibers. They contain few mitochondria.