Home | Work & Business | Science & Technology | Human Skeleton | Structure of Human Skeleton

Structure of Human Skeleton

by Lysis

Overview

The human skeleton is an integral part of the body that provides protection and support. Bones like the skull and rib cage protect underlying organs like the heart, lungs and brain. Appendicular skeletal bones like the arms, fingers, legs and toes provide structural movement. Together with the muscles, the skeleton allows people to play, run, jump, walk and eat. In addition to support, the inner tissue of the bones supply the body with blood cells for nutrients and immunity.
Axial

The axial skeleton is comprised of the ribs, skull and vertebrae. The skull is the very hard bone that surrounds the brain and creates the facial features. The skull protects the brain from trauma and is separated into sections that are connected by tiny bones called sutures. The vertebrae expand vertically down from the skull. Within the hollow circle of the vertebrae rests the spinal cord. The vertebrae protect the spinal cord from damage. Finally, the rib cage is used to protect the heart and lungs from damage. There are 12 pairs of ribs that extend around the organs from the vertebrae.

Appendicular

The appendicular skeleton is comprised of the arms, legs, shoulders feet and hands. The appendicular part of the skeleton is mainly used for movement. The bones are connected to each other using ligaments, and tendons are used to connect each movable bone to a muscle. Included in the appendicular skeleton is the femur. The femur is the largest bone in the body and has the most bone marrow for blood cell creation.
Marrow

Marrow is the soft, spongy tissue inside the hardened bone. The marrow is the site in the body for hematopoiesis, which is the process in which stem cells are created. These cells differentiate into a specific lineage of white blood cells. The bone marrow also creates red blood cells, which are protein structures that attach to oxygen in the lungs and deliver it to body tissue.
Ligaments and Tendons

Ligaments and tendons are the connective tissue of the skeleton. Ligaments are located between the bone to help form a joint. This tissue is durable, and some ligament tissue restricts movement of the joint. Tendons are responsible for the connection to muscles. The tendon are also durable and resist tension when the muscle contracts. Both ligament and tendon tissue is made of cartilage.
Movement

Although the bones do not create movement, they are an integral part of movement in the body. Movement starts with a brain electrical impulse that runs down to nerve fibers. These nerves innervate the muscle, causing them to contract. When contraction occurs, the muscle's tendon pulls on the skeletal bone. The bone is lifted and movement is produced. This happens for any activity in the body like walk, moving the arms, eating and typing.