The skeleton of the upright human, composed of 206 bones in the adult, provides support, mobility, and protection for the vital organs. The spinal column, along with the skull and rib cages, is called the Axial skeleton. The bones of the arms, hands, legs, and feet, plus the shoulder and pelvic bones, make up the Appendicular skeleton.
Just as the skull protects the brain, so the rib cage protects the lungs and heart. But the intricately jointed bones of hands and feet are devised for movement.
The red blood cells, suppliers of oxygen to the body, are produced by the trillions in the red marrow of such bones as the vertebrae, femur and ribs. If you are getting sufficient iron and proteins in your diet, you are helping to nourish these red blood cells.
Vitamins of the B family are good for the bone marrow, and the hard outer structure of the bones requires calcium, a mineral found in both whole and skim milk. Vitamin D is also necessary in the manufacture of bone; it has been added as a supplement to most of the milk available in the market.
Generally, the bone is as strong as cast iron, but infinitely lighter and more flexible. Its rigidity enables us to bear our own weight, plus the stress of lifting and carrying. But the mechanically ingenious joints—some of ball-and-socket construction, others like levers or hinges—make us creatures of amazing agility.
Ligaments, bands of tough tissues, connect the bones to one another when they come together to form a joint. The joints provide the smooth, gliding surfaces at the end of bones so that movements can be carried out easily and painlessly.
Nature provides a flexible material called cartilage for the ends of the bones involved in our bodily movements. This material decreases friction so that fingers, arms and legs can move thousands of times daily without one being conscious of their activities.
To bind the bones together and strengthen joints, nature uses a special type of tough binding cords called ligaments. These are attached to the bones so well that only exceptional strains will tear the elastic ligament away from the bone.
A similar type of tough connective tissue that connects muscles to bone is called a tendon, but tendons do not stretch.
A final element in the smooth and effective movement of our joints is the bursa—a sac, or bag, with smooth surfaces that contains a small amount of lubricating material. The bursas permit the smooth functioning of the joints. When you get housemaid’s knee, it is the bursa that swells.
An injured ligament or an inflamed bursa can be extremely painful. A strained joint is one in which the ligament has been severely stretched without being torn; in a sprain, some of the fibers are actually torn. Injured ligaments require a great deal of rest to help them heal, so avoid the problem by learning the correct use of your body in lifting and in strenuous sports.
You can protect your joints from strain by practicing good posture and by keeping your weight down. Overweight people are constantly overloading the joints of the knees, feet and spine. Unusual pain or inflammation or swelling in the joints can indicated a number of possible ailments and should be checked by your doctor.
The Scaffolding of the Body
The body owes its shape and support to the skeleton—a scaffolding consisting of hundreds of jointed bones. Contraction of muscles anchored to the bones brings about all bodily movements, such as grasping, carrying, bending, walking and running.
The different parts of the body’s scaffolding are:
Head: the bones of the skull surround and protect the brain; the lower jaw is hinged to the skull
Chest: the bony cage of the ribs, connected to the spine at the back and the breastbone of the front, surround and protect the organs in the chest
Arms: the bones of the arms are jointed to sockets on the shoulder blades
Spinal Column: the seven vertebrae in the neck and the 20 in the back make the spinal column
Pelvis: the bones of the pelvis surround the lower abdominal organs, support the spine and provide attachments for the legs
Hand: eight bones make up the wrist, five the palm and 14 bones form the fingers and thumb
Leg: three major leg bones are suspended by ball-and-socket joints from the pelvis
Foot: the bones of the foot form arches, so that the weight is carried on the heels and toes
How to Protect Your Bones
A good diet and safety measures that prevent accidents provide the best protection you can give your bones and ligaments. Accidents do happen, however, and if the victim is suffering great pain or you notice a deformity of any injured part, it is possible that the bone is fractured.
Do not move a person if a fracture of the back or neck is suspected. If the fracture is in a limb, however, and the person must be moved, immobilize the injured section with splints.
When properly set by a physician, bones have remarkable healing powers. As people grow older, however, the bones become more brittle and heal less easily. For this reason, physicians fear certain fractures in the elderly more than in young people.
A family with an older member should be cautious about icy or wet steps, floor clutter or anything else that could cause a fall.
Backache is so common that it could almost be considered one of the penalties we pay for walking upright. We are not personally responsible for how we are created, but when we put undue strain on out-of-condition muscles—such as by digging up the garden or any other strenuous activities after being inactive for months—we are tempting fate!
Persistent backache should be treated with rest and a doctor’s attention. You can help a strained back by sleeping on a hard bed and sitting in straight chairs only
Development of the Axial Skeleton and Intervertebral Disc by Sade Williams, Bashar Alkhatib and Rosa Serra
Joints in the Appendicular Skeleton: Developmental Mechanisms and Evolutionary Influences by Danielle Rux et al
Vitamin D and Systemic Lupus Erythematosus: Bones, Muscles, and Joints by Nancy Lane