Question

Sigmoid notch is found in:
A) Tibio-fibula
B) Femur
C) Radio-ulna
D) Humerus

Answer 1

Hint:
One bone is smaller than the other and another one is larger. these are the bones of the forearm. The Styloid process is present in the distal end of these bones. This bone forms nutrient foramina. These bones are present on the thumb side and little finger side.

Complete step by step solution:
Sigmoid notch is a type of large depression that is present in the upper extremity of the ulna and this part fits in the trachea of the humerus. The distal end of the humerus at the elbow joint is like a pully and is called the trochlea. The trochlear notch is found in the humerus and the trochlea of the humerus forms a part of the elbow joint and is formed by the coronoid process and electron process. The Olecranon process is present in the ulna, proximally which forms the prominence of the elbow. Its groove is called the olecranon fossa whose basal part is marked by a supratrochlear foramen for the passage of the branchial artery and nerve. A fibular notch is found in the tibia and fibula. The intercondylar notch is found in the femur.
Additional information Bones of the arms provide strength to make the arms effective in working with them. Carpals are arranged in two rows, with 4 bones in each row. Metacarpals are five in number, and phalanges are fourteen, phalanges formula= 2,3,3,3,3.

Option ‘C’ is correct

Note:
In the human arm, the joints are more moveable than in the forelimbs of animals, metacarpals form a wide palm and the thumb is opposable. Animals use their forelimbs mainly for locomotion whereas men use them for grasping.