Question

Which of the following contains a greater trochanter?
A. Humerus
B. Radius
C. Ulna
D. Femur

Answer 1

Hint: Animals and plants exhibit a wide range of movements. Movements are a significant feature of living organisms. Human beings can move limbs, jaws, eyelids, tongue etc. walking, running, climbing, flying, swimming are examples for locomotor movements. Humans use limbs for locomotion and movements as well.

Complete Answer:
- Skeletal system is a framework of bones and cartilage. It has a big role in our movements. We can chew food with jaw bones and walk around our place with limb bones. Bones and cartilages are specialized connective tissues. Blood has a hard matrix due to calcium salts and due to chondroitin salts, cartilage has a slightly pliable matrix.

- Human beings contain 206 bones and a few cartilages. They are grouped into two, appendicular and axial systems.
- Axial skeleton contains 80 bones, which are distributed along the axis of our body. Axial skeleton is composed of the skull, vertebral column, ribs and sternum. Skull has 22 bones, 6 ear ossicles, vertebral column containing 26 vertebrae, 1 hyoid bone, 1 breast bone sternum, 24 ribs.

- The bones of limbs and their girdles constitute the appendicular system. Each limb is made up of 30 bones. The bones of the forelimb are humerus, radius, and ulna, carpals, metacarpals and phalanges.
- Bones of hind limbs are femur, which is the longest bone, tibia and fibula, tarsals, metatarsals and phalanges. Cup shaped bone patella covers the knee.

- Femur can act as a site of origin and attachment of many muscles and ligaments. Proximal aspect of femur articulates with the acetabulum of pelvis to form the hip joint. It comprises the head, neck and two bony processes called greater and lesser trochanters. Greater trochanter is irregular, large portion of longest bone femur. Thigh muscle and hip muscle joins at the trochanter region of femur. It is the site of attachment of many muscles.

So, here the correct answer is D) Femur.

Figure: Femur

Additional information:
- Bones of the limb along with their girdles constitute the appendicular skeleton.
- Pectoral and pelvic girdle bones help in the articulation of the upper and lower limbs respectively with the axial skeleton.
- Pelvic girdle is formed of two coxal bones. Each coxal bone is formed by the fusion of three bones,namely ilium, ischium and pubis.

Note: Three types of joints are formed between bones or between bone and cartilage. They are fibrous joints, cartilaginous joints and synovial joints. Fibrous joints do not allow any movement, it is found in the skull. Cartilaginous joints allow limited movements, found in the vertebral column. Synovial joints allow considerable movements. Ball and socket joint, hinge joint, pivot joint etc. are examples for synovial joints.