1st January 2007
A Mini Course in Anatomy

A Mini Course in Anatomy - Part 1

By Tace Allen

When comparing basic human and canine anatomy together, you will see that they are very alike but for one noticeable major difference being that our dogs walk on all fours, so their limbs are positioned slightly differently from ours.

There are 9 different systems that operate within the body and all are inter-related.

1. Skeletal
2. Muscular
3. Respiratory (breathing)
4. Circulatory or Vascular
5. Nervous
6. Digestive or Alimentary
7. Excretory or Urinary (waste products)
8. Endocrine or Glandular
9. Reproductive

The Skeletal System

The Skeletal system acts as a scaffold for the muscles to attach onto. It protects the dog's vital organs and tissues e.g. the brain is protected by the skull, the lungs and heart are protected by the ribcage and the spinal cord is protected by the vertebral column.

There are over 200 bones within the body and all have a different function, they are adapted to this by their size, shape and structure. The skeleton can be divided into 2 parts: the APPENDICULAR SKELETON which consists of the limbs, shoulder and pelvic girdles. The AXIAL SKELETON, comprises the skull, vertebral column, ribcage and sternum.

There are 4 types of bones:

Long bones - Found in the limbs, they function as levers and as a weight support.

Short bones - Found in the joints e.g. the knee, these bones absorb concussion.

Flat bones - These bones protect and enclose vital organs, for example, the ribcage encloses the heart and lungs and the skull encloses the brain. The flat bones provide a large surface area for muscle attachment.

Irregularly shaped bones - They are found within the spinal column and limbs and offer attachments for muscles, tendons and ligaments.

Within the skeleton

Ligaments - Connective tissue that connects bone to bone, they are made up of collagen fibres and have a limited blood supply, if it is injured it tends to heal slowly. Ligaments are located around joints to give extra support and prevent excessive range of movement.

Tendons - Connects a muscle to a bone. The origin or start of a muscle is where the tendon attaches the muscle to the least movable bone; the insertion or end point of a muscle is where the tendon attaches the muscle to the movable bone.

Joints - Where 2 bones meet. Movement of the dog depends upon muscle contraction and articulation of the joints. The ends of bones are lined with hyaline cartilage, this provides a smooth surface between the bones and acts as a shock absorber e.g. whilst jumping.