Question

Olecranon fossa is present over
A) Scapula
B) Ulna
C) Radius
D) Humerus

Answer 1

Hint: In human beings, the bones in the skeletal system are classified as the axial and appendicular skeleton depending on their location. Various articulating bones connect the bones of the appendicular skeleton to that of the axial skeleton.

Complete answer:
Olecranon fossa is a bony depression that is triangular, that is present over the humerus, which is the bone present in the forearm, extending from the shoulder to the elbow. The depression is present on the posterior part of the humerus. The part lies superior to the Trochlea, the summit of the Olecranon is received to this part while the forearm gets extended. These structures work together and facilitate the extension of the elbow.

                       Figure: The parts of humerus showing the location of Olecranon fossa

Considering the other given options:
-The scapula is also commonly known as the shoulder bone. This bone functions as a connection point between the humerus and the clavicle also known as the collarbone. There are two scapulae present in the human body on either side. The bone is a part of the shoulder girdle. Thus it is not the right option.
-The ulna is a long bone that is found in the forearm. It gets extended from the elbow and ends at the smallest finger. Thus it is not the right option.
-Radius is also a bone that is present in the forearm. It exists in pairs with the ulna. But has a comparatively larger size than the Ulna due to its thickness. Thus it is not the right option.
-Therefore from the above-given options, the most appropriate answer is D. That is, olecranon fossa is a triangular depression present over the humerus.

Hence the correct answer is option ‘D’.

Note: There are two other depressions present above the trochlea on the anterior side. They are known as the coronoid fossa and the radial fossa. They are connected to the heads of the ulna and radius.