NCERT Solutions for Chapter: Locomotion and Movement, Exercise 4: LONG ANSWER TYPE QUESTIONS

Calcium ion concentration in the blood affects muscle contraction. Does it lead to tetany in certain cases? How will you correlate fluctuation in blood calcium with tetany?

An elderly woman slipped in the bathroom and had severe pain in her lower back. After X-ray examination doctors told her it is due to a slipped disc. What does that mean? How does it affect our health?

Explain sliding filament theory of muscle contraction with neat sketches.

How does a muscle shorten during its contraction and return to its original form during relaxation?

Discuss the role of ${\mathrm{Ca}}^{++}$ ions in muscle contraction. Draw neat sketches to illustrate your answer.

Differentiate between Pectoral and Pelvic girdle.