Skeletal System Essay Conclusion
The spinal cord, a pathway for messages between the brain and the body, is protected by the backbone, or spinal column.The ribs form a cage that shelters the heart and lungs, and the pelvis helps protect the bladder, part of the intestines, and in women, the reproductive organs.Even when we sit perfectly still, muscles throughout the body are constantly moving.Muscles help the heart beat, the chest rise and fall during breathing, and blood vessels regulate the pressure and flow of blood.Recently, it has been recognized that, during bone remodeling, there are an intricate communication among bone cells.For instance, the coupling from bone resorption to bone formation is achieved by interaction between osteoclasts and osteoblasts.When you decide to move, the motor cortex sends an electrical signal through the spinal cord and peripheral nerves to the muscles, making them contract.
The bones of kids and young teens are smaller than those of adults and contain "growing zones" called growth plates.
This process is under the control of local (e.g., growth factors and cytokines) and systemic (e.g., calcitonin and estrogens) factors that all together contribute for bone homeostasis.
An imbalance between bone resorption and formation can result in bone diseases including osteoporosis.
Muscles can pull bones, but they can't push them back to the original position. For example, the biceps muscle, in the front of the upper arm, is a flexor, and the triceps, at the back of the upper arm, is an extensor. Then the biceps relaxes and the triceps contracts to straighten the elbow. They make the skeleton flexible — without them, movement would be impossible. Some joints open and close like a hinge (such as knees and elbows), whereas others allow for more complicated movement — a shoulder or hip joint, for example, allows for backward, forward, sideways, and rotating movement.
Department of Morphology, Laboratory of Histology and Embryology, Dental School, Universidade Estadual Paulista (UNESP), 14801-903 Araraquara, SP, Brazil Received 3 December 2014; Revised 30 April 2015; Accepted Academic Editor: Wanda Lattanzi Copyright © 2015 Rinaldo Florencio-Silva et al.