The adult human skeleton is a marvel of engineering, design and aesthetics. The approximately 206 bones range in size from the small stapes found in the inner ear to the femur, the longest in the body.
The body is full of interesting bones! There are bones in the body that act to reduce the weight of the skull, these sinuses are found in the frontal, maxillary, ethmoid and sphenoid bones. The patella, a sesamoid bone, acts to reduce the friction of the quadriceps tendon as it glides across the femoral condyles allowing you to flex your knee. The ischium (one of three bones that form the hip bone) supports your weight as you sit. The axis, the second cervical vertebra allows you to rotate your head from side to side.
The bones of the skeleton act in concert to support the body by creating a hard framework that anchors the organs, protects the brain, eyes and ears, and spinal cord. Bones act as storage sites for fat in their yellow marrow. Within the structure of bone itself minerals are stored such as calcium, potassium, sodium, sulphur, magnesium and copper. Blood cell formation occurs within the red marrow cavities of bones.
Most importantly the skeleton allows us to move. The skeleton acts as a site of origin and insertion of skeletal muscles, which act as levers allowing, everything from finely controlled motion to large gross movements.
The skeleton is actually broken into two parts, the axial skeleton and the appendicular skeleton. The axial skeleton, as it’s name indicates, forms the axis of the body, and it includes the bones of the skull, the hyoid, vertebral column, ribs and sternum.
The appendicular skeleton includes all the bones of the upper and lower limbs and the clavicle, scapula and hip (innominate) bones.
Thanks for reading. Future blog postings will cover topics such as functional anatomy of the vertebral column, anatomy review of the central nervous system, concentric and eccentric disc herniation and more.
Illustrations copyright Marie Dauenheimer.