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The diagram below illustrates the arrangement of bones and muscles in the human arm.

The diagram below illustrates the arrangement of bones and muscles in the human arm.
Biology5262017822.jpg
(i) Name the bones labelled K and L.
(ii) Explain how the upwards movement of the lower arm is brought about by the bones and muscles shown in the diagram above.

Answers


John
(1) - K - Ulna,

L - Humerus

(ii) Movement of the lower arm takes place at the elbow which is between ulna and the humerous muscles. Involves are biceps and triceps which operate as a pair and their function is antagonistic. When the biceps/ flexor muscles contract, triceps/ extensor muscles relax. This pulls ulna and radius upward, thereby bending the arm or bringing the lower arm upward.
johnmulu answered the question on May 26, 2017 at 05:31

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