Locomotion and Movement
இடப்பெயர்ச்சியும் இயக்கமும்
- 1Types of Movement and Muscle
All locomotion is movement, but not all movement is locomotion. And only skeletal muscle is both striated and voluntary — visceral is smooth and involuntary, cardiac is striated but involuntary.
- 2Structure of Skeletal Muscle
The A band never changes length during contraction — the I band and H zone shrink. If a statement says 'A band widens', it is false.
- 3Mechanism of Muscle Contraction
Calcium does not pull anything. It binds troponin, which moves tropomyosin off actin's active sites — only then can myosin heads grab actin. That single step is NEET's favourite question in this chapter.
- 4Axial Skeleton
12 pairs of ribs, but only 7 are true ribs. The 8th, 9th and 10th are false (vertebrochondral) ribs, and the 11th and 12th float. Every count question in this chapter comes back to these numbers.
- 5Appendicular Skeleton
The glenoid cavity is on the scapula and holds the head of the humerus — that is your shoulder joint. The acromion is the flat end of the scapula's spine that forms the point of the shoulder.
- 6Joints
The joint between atlas and axis is a pivot joint — and pivot joints are synovial. Students who answer 'fibrous' or 'cartilaginous' have mixed up the type with the sub-type.
- 7Disorders of Muscular and Skeletal System
Myasthenia gravis is autoimmune; muscular dystrophy is genetic. Tetany comes from LOW calcium, not high. These three swaps cost students marks every single year.