Technical Introduction
This section is intended to give you some initial detail about the human anatomy before starting to draw. I have described the properties of bones, muscles, tendons, cartilage, skin, fat and joints, and shown diagrams of the different types of joints and muscles. There is also an introduction to anatomical terminology: you will find this useful as certain terms are used throughout the book.
BONES
The skeleton is the solid framework of the body, partly supporting and partly protective. The shape of the skeleton can vary widely. It affects the build of a person and determines whether they have masses of muscle and fat or not.
Bones are living tissue supplied by blood and nerves. They can become weaker and thinner with malnutrition and lack of use or heavier and stronger when having to support more weight. They are soft and pliable in the embryo, and only become what we would consider hard and bone-like by the twenty-fifth year of life.
Humans have 206 bones, but it is possible to be born with some bones missing or even extra ones, and a few bones fuse together with age. We each have a skull, ribcage, pelvis and vertebral column, as well as arm, hand, leg and foot bones. Most bones are symmetrical. The bones of the limbs are cylindrical, thickening towards the ends. The projecting part of a bone is referred to as a process or an eminence.
Highly mobile areas of the body, such as the wrists, consist of numerous small bones. Other bones, like the scapula (shoulder blade) can move in all directions, controlled by the muscles around them.
The bones of the cranium (skull) differ from all others. They grow from separate plates into one fused vault to house the brain. The mandible (jawbone) is the only movable bone in the head.
The long bones of the arms and legs act like levers, while the flat bones of the skull, the cage-like bones of the ribs and the basin shape of the pelvis protect the more vulnerable organs such as the brain, heart, lungs, liver and the abdominal viscera.
MUSCLES
The combination of bones, muscles and tendons allows both strong, broad movements and delicate, precise ones. Muscles perform our actions by contracting or relaxing. There are long muscles on the limbs and broader muscles on the trunk. The more fixed end of the muscle is called the head or origin, and the other end â usually farthest from the spine â is the insertion. There are powerful, thick muscles, like the biceps and the ring-shaped muscles (sphincters) surrounding the openings of the body, such as the eye, mouth and anus. Certain muscles grow together and have two, three or four heads and insertions. Combined muscles also have parts originating in different places. The fleshy part of a muscle is called t...