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

(i) Name the bones labeled K and L
(ii) Explain how upward movement of the lower arm is brought about by bones and muscles shown in the diagram above

Answer Text:
i)- K:ulna
- L: humerus
ii)- Movement of the lower arm take place at the elbow which is between ulna and the humorous muscles involved biceps and triceps which operate as a pair and their function is antagonistic. When the biceps muscles contract triceps muscles relax. This pulls ulna and radius upward thereby
bending the arm or bringing the lower arm upward.