The human body is an incredibly complex organism made up of various systems, including the skeletal system. The skeletal system is responsible for providing support, protection, and movement to the body.
It is essential for military and navy personnel to have a comprehensive understanding of the human skeleton to perform their duties efficiently.
In this article, we will explore the divisions of the human skeleton, their functions, and their importance.
Key takeaways
- The human skeleton is divided into two main divisions: the axial skeleton and the appendicular skeleton.
- The axial skeleton includes the skull, the vertebral column, and the thorax, and is responsible for protecting the brain, eyes, and ears.
- The skull consists of 28 bones, including the cranial and facial bones. The cranial bones form the cranium and are joined by sutures, while the facial bones form the upper and lower jaw and the framework of the face.
- Military and Navy personnel can benefit from understanding the human skeleton, as it plays a crucial role in overall health and physical fitness, as well as in preventing injuries and understanding the effects of trauma.
- The Naval Education and Training Command (NAVEDTRA) has developed a training manual that covers the human skeleton and its functions in detail, providing a valuable resource for military and Navy personnel seeking to improve their knowledge in this area.
Divisions of the skeleton
The human skeleton is divided into two main divisions: the axial skeleton and the appendicular skeleton.
The axial skeleton consists of the skull, vertebral column, and thorax.
The appendicular skeleton includes the upper and lower extremities, pelvic girdle, and pectoral girdle.
Axial skeleton
The axial skeleton plays a crucial role in providing support and protection to the body’s vital organs.
Let us look at each component of the axial skeleton in more detail.
The skull
The skull is one of the most complex structures of the axial skeleton. It consists of 28 bones, 22 of which form the framework of the head and provide protection to the brain, eyes, and ears, while six are ear bones.
With the exception of the lower jaw bone and ear bones, all skull bones are joined together and fixed in one position.
The bones of the face form a complex framework that helps to shape facial features, the upper jaw (maxilla), and lower jaw (mandible).
Except for the mandible and bones of the inner ear, all skull bones are joined firmly along seams known as sutures.
The bones of the skull are classified as cranial or facial bones.
Cranial bones
The cranium is formed by eight major bones, most of which are in pairs. These include:
- Frontal bone: This bone forms the front part of the skull above the eyes, including the forehead and part of the nasal cavity. In children, the frontal bone develops as two parts, which fuse together by age 5 or 6. The frontal sinuses (air spaces in the bone) are located above each eye socket.
- Parietal bones: These two bones are located behind the frontal bone and form the greater part of the right and left sides and the roof of the skull. They each have four borders and are shaped like a curved plate.
- Temporal bones: The temporal bones form the sides and part of the base of the skull in the area of the ear. One temporal bone is located on each side. It encloses the internal ear structures and has depressions called glenoid fossae that form the articulation with the mandible.
- Occipital bone: This bone forms the back part of the skull and the base of the cranium. It joins with the parietal and temporal bones. In the center, the underside (inferior) portion of the cranium, there is a large opening called the foramen magnum, through which nerve fibers from the brain pass and enter into the spinal cord.
- Ethmoid bone: The ethmoid bone is situated in front of the sphenoid bone in the front part of the cranium. Through small openings in this bone pass nerves to the roof of the mouth that are responsible for the sense of smell.
- Sphenoid bone: The sphenoid bone is posterior to the ethmoid bone, providing for the front base of the cranium and forming the floor and sides of the orbits.
Functions of the axial skeleton
The axial skeleton provides support and protection for the body’s vital organs.
The skull protects the brain, eyes, and ears, while the vertebral column encases and protects the spinal cord.
The thorax includes the ribs and sternum, providing a protective cage.
Appendicular skeleton
The appendicular skeleton consists of the upper and lower extremities and the girdles that attach the limbs to the axial skeleton.
The upper extremities consist of the clavicle, scapula, humerus, radius, ulna, carpals, metacarpals, and phalanges.
The lower extremities consist of the pelvic girdle, femur, tibia, fibula, patella, tarsals, metatarsals, and phalanges.
Bones of the pelvic girdle
The pelvic girdle is formed by two coxal bones, commonly referred to as the hip bones.
Each hip bone is made up of three bones: the ilium, the ischium, and the pubis.
At birth, these bones are separate, but by the time full growth is reached, they are fused together.
The fusion of these bones forms a basin-shaped structure called the pelvic girdle, which supports the trunk of the body and provides attachment for the lower limbs.
Training on skeletal anatomy
Understanding the anatomy of the human skeleton is important for various professions, including medical personnel, physical therapists, and athletic trainers.
For those in the military and navy, a comprehensive knowledge of the skeletal system is necessary to provide proper medical care for injured soldiers and sailors.
One training manual that the military and navy uses for this purpose is the Naval Education and Training Command’s (NAVEDTRA) Hospital Corpsman Manual.
This manual includes a detailed description of the skeletal system, along with illustrations and exercises to help corpsmen understand the various bones and their functions.
The importance of maintaining skeletal health
In addition to its role in providing structural support for the body, the skeletal system also plays a vital role in protecting organs and producing blood cells.
It is important to maintain skeletal health throughout one’s life to prevent injuries and illnesses such as osteoporosis, a condition in which bones become brittle and fragile.
Maintaining skeletal health involves engaging in weight-bearing exercises, consuming adequate amounts of calcium and vitamin D, and avoiding smoking and excessive alcohol consumption.
Proper posture and body mechanics also play a role in preventing skeletal injuries.
Conclusion
The human skeletal system is a complex structure that plays a crucial role in the functioning of the body.
Divided into the axial and appendicular skeletons, it consists of various bones that provide structural support, protect organs, and produce blood cells.
Understanding the anatomy of the skeletal system is important for medical professionals, athletic trainers, and anyone interested in maintaining skeletal health.
The military and navy use training manuals such as NAVEDTRA’s Hospital Corpsman Manual to teach corpsmen about the skeletal system, which is crucial in providing proper medical care for injured soldiers and sailors.
