In a human arm, the phalanges are to the humerus.
a. distal
b. proximal
c. medial
d. lateral
e. superior
The Correct Answer and Explanation is:
Correct Answer: a. distal
Explanation:
In anatomical terminology, “distal” refers to a position farther from the point of attachment or the trunk of the body, while “proximal” means closer to the point of attachment.
In the human arm, the humerus is the long bone of the upper arm, extending from the shoulder to the elbow. It connects the upper limb to the shoulder girdle. The phalanges are the bones of the fingers, located at the end of the arm, farthest from the shoulder joint.
Here’s how they are positioned:
- The humerus is attached to the scapula at the shoulder joint.
- The radius and ulna are the forearm bones, located between the humerus and the hand.
- The carpals (wrist bones) come next, followed by the metacarpals (hand bones).
- Finally, the phalanges are the bones of the fingers at the farthest point.
So, if we compare the position of the phalanges relative to the humerus, the phalanges are clearly further away from the trunk or the point of attachment. Therefore, they are distal to the humerus.
To clarify the incorrect options:
- b. Proximal would mean closer to the trunk, which is the humerus—not the phalanges.
- c. Medial means closer to the midline of the body; this does not apply here.
- d. Lateral means further away from the midline of the body, which is more comparative and not appropriate in this case.
- e. Superior means above in anatomical position (toward the head), which also doesn’t accurately describe the relationship between the phalanges and the humerus.
Thus, “distal” is the most accurate term for the position of the phalanges in relation to the humerus.