Axial skeleton
Encyclopedia
The axial skeleton consists of the 80 bones along the central axis of the human body. It is composed of six parts; the human skull
Human skull
The human skull is a bony structure, skeleton, that is in the human head and which supports the structures of the face and forms a cavity for the brain.In humans, the adult skull is normally made up of 22 bones...

, the ossicles
Ossicles
The ossicles are the three smallest bones in the human body. They are contained within the middle ear space and serve to transmit sounds from the air to the fluid-filled labyrinth . The absence of the auditory ossicles would constitute a moderate-to-severe hearing loss...

 of the middle ear, the hyoid bone
Hyoid bone
The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...

 of the throat, the rib cage
Rib cage
The rib cage is an arrangement of bones in the thorax of animals. It is formed by the vertebral column, ribs and sternum and encloses the heart and lungs....

, sternum and the vertebral column
Vertebral column
In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...

. The axial skeleton and the appendicular skeleton
Appendicular skeleton
The Appendicular skeleton is composed of 126 bones in the human body. The word appendicular is the adjective of the noun appendage, which itself means a part that is joined to something larger...

 together form the complete skeleton
Human skeleton
The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, muscles and cartilage. It serves as a scaffold which supports organs, anchors muscles, and protects organs such as the brain, lungs and heart....

.

Overview

Flat bone
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...

s house the brain
Human brain
The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...

, spinal cord
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...

, and other vital organs. This article mainly deals with the axial skeletons of humans; however, it is important to understand the evolutionary lineage of the axial skeleton. The human axial skeleton consists of 80 different bones. It is the central core of the body and where the appendicular skeleton attaches. As the skeleton grows older the bones get weaker with the exception of the skull. The skull remains strong to protect the brain from injury.

Etymology

The word "Axial" is taken from the word "axis" and refers to the fact that the bones are located close to or along the central axis of the body.

Skull

Skull (22)
  • Cranial Bones (8)
    • Parietal (2)
    • Temporal (2)
    • Frontal (1)
    • Occipital (1)
    • Ethmoid (1)
    • Sphenoid (1)

  • Facial Bones (14)
    • Maxilla (2)
    • Zygomatic (2)
    • Mandible (1)
    • Nasal (2)
    • Palatine (2)
    • Inferior nasal concha (2)
    • Lacrimal (2)
    • Vomer (1)

Hyoid bone

Hyoid bone (1)
U-shape bone located in the neck. It anchors the tongue and is associated with swallowing.

Vertebral column

Vertebral Column (26)
  • Cervical vertebrae (7)
  • Thoracic vertebrae (12)
  • Lumbar vertebrae (5)
  • Sacrum (1) (5 at birth, later fused in adult stage)
  • Coccyx (1) (4 at birth, later fused to form one single bone, varies between 3-5)

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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