The Skeleton

In this chapter you will learn how the skeleton maintains the shape of the body, protects internal organs like the brain, heart and lungs, enables the animal to move and hear sound.

Objectives

After completing this section, you should know:

• the functions of the skeleton
• the basic structure of a vertebrae and the regions of the vertebral column
• the general structure of the skull
• the difference between ‘true ribs’ and ‘floating ribs
• the main bones of the fore and hind limbs, and their girdles and be able to identify them

in a live cat, dog, or rabbit

• the basic structure of a long bone
• the structure of compact and spongy bone and where they are found
• different kinds of joints and where they are found and the basic structure of a synovial joint
• the common name for a variety of joints
• different modes of locomotion including plantigrade, digitigrade and unguligrade.

Summary

• The skeleton maintains the shape of the body, protects internal organs and makes locomotion possible.
• The vertebrae support the body and protect the spinal cord. They consist of: cervical vertebrae in the neck, thoracic vertebrae in the chest region which articulate with the ribs, lumbar vertebrae in the loin region, sacral vertebrae fused to the pelvis to form the sacrum and tail vertebrae.
• The skull protects the brain and sense organs. The cranium forms a solid box enclosing the brain. The mandible forms the jaw.
• The forelimb consists of the humerus, radius, ulna, carpals, metacarpals and phalanges. It moves against or articulates with the scapula at the shoulder joint.
• The hindlimb consists of the femur, patella, tibia, fibula, tarsals, metatarsals and digits. It moves against or articulates with the pelvis at the hip joint.
• Bones articulate against each other at joints.
• Compact bone in the shaft of long bones gives them their strength. Spongy bone at the ends reduces weight. Bone growth occurs at the growth plate.

Learning Activities

Library of Resources

Presentations and Blackboard quizzes can be accessed by students of Otago Polytechnic.