How the human skeleton works?

Without a skeleton, we would not be able to live. It is what gives us our shape and structure and its presence allows us to operate on a daily basis. It also is a fascinating evolutionary link to all other living and extinct vertebrates.

The human skeleton is crucial for us to live. It keeps our shape and muscle attached to the skeleton allows us the ability to move around, while also protecting crucial organs that we need to survive. Bones also produce blood cells within bone marrow and store minerals we need released on a daily basis.

As a fully grown adult you will have around 206 bones, but you are born with over 270, which continue to grow, strenghten and fuse after birth until around 18 in females and 20 in males. Human skeletons actually do vary between sexes in structure also. One of the most obvious areas are pelvis as a female must be able to give birth, and therefore hips are comparatively shallower and wider. The cranium also becomes more robust in males due to heavy muscle attachment and a male's chin is often more prominent. Female skeletons are generally more delicate overall. However, although there are several methods, sexing can be difficult because of the level of variation we see within the species.

Bones are made up of various different elements. In utero, the skeleton takes shape as cartilage, which then starts to calcify and develop during gestation and following birth. The primary element that makes up bone, osseous tissue, is actually mineralised calcium phosphate, but other forms of tissue such as marrow, cartilage and blood vessels are also contained in the overall structure. Many individuals think that bones are solid, but actually inner bone is porous and full of little holes.

As we age, so do our bones. Even though cells are constantly being replaced, and therefore no cell in our body is more than 20 years old, they are not replaced with perfect, brand-new cells. The cells contain errors in their DNA and ultimately our bones therefore weaken as we age. Conditions such as arthritis and osteoporosis can often be caused by ageing and cause issues with weakening of bones and reduced movement ability.

Here are some of the most important bones:

  • Cranium - The cranium, also known as the skull, is where the brain and the majority of the sensory organs are located.
  • Vertebrae - There are three main kinds of vertebrae (excluding the sacrum and coccyx) - cervical, thoracic and lumbar. These vary in strength and structure as they carry different pressure within the spine.
  • Pelvis - This is the transitional joint between the trunk of the body and the legs. It is one of the key areas in which we can see the skeletal differences between the sexes.
  • Femur - This is the largest and longest single bone in the body. It connects to the pelvis with a ball and socket joint.
  • Fibula/Tibia - These two bones form the lower leg bone and connect to the knee joint and the foot.
  • Rib cage - This structure of many single bones creates a protective barrier for organs situated in the chest cavity. They join to the vertebrae in the spine at the back of the body, and the sternum at the front.
  • Radius/Ulna - The radius and ulna are the bones situated in the forearm. They connect the wrist and the elbow.
  • Sternum, Scapula and Collarbone
It is well documented that Yoga strengthens bones and helps ward off osteoporosis. Many postures in yoga require that you lift your own weight. And some, like Downward and Upward-Facing Dog, help strengthen the arm bones, which are particularly vulnerable to osteoporotic fractures. Yoga practice increased bone density in the vertebrae. Yoga'a ability to lower levels of the stress hormone cortisol may help keep calcium in the bones.