Locomotion & Structure of skeletal muscles

Q. Describe the location and structure of skeletal muscles.

Ans: i. Location: Major part of skeletal muscles which move the bones do not lie on the same bone but they are located on the bone atop. e.g. Biceps and triceps that move the forearm are located in the upper arm.

ii. Structure: At any joint, two types of bones are present i.e., stationary and movable. The end of the skeletal muscle to which the stationary bone is attached is called the origin whereas the opposite end attached to movable bone is called insertion. The middle thick part of the muscle is called as belly. All the fibres in a muscle do not extend from end to end and they are maximum in the middle part of the muscle. Thus, most of the large muscles are fusiform in shape.

Q. Explain the types of straited muscles.

Ans: On the basis of movements, striated muscles are of three types:

i. Agonists: are considered as the prime movers. They bring about the initial movement of a part. E.g.: biceps.

ii. Antagonists: They bring about the action opposite to that of prime movers. e.g. Triceps.

iii. Synergists: They assist the prime movers. e.g. Brachialis assist biceps.