The Axial Skeleton is the central core of the human body housing and protecting it’s vital organs. It includes the bones that form the skull, laryngeal skeleton, vertebral column, and thoracic cage. The axial skeleton consists of 80 bones.
The Axial Skeleton has following important functions:
- Its support and protect the organs in the dorsal and ventral cavities.
- It creates a surface for the attachment of muscles.
The skull consists of 22 bones, which are divided into two categories:
- Cranial bones
- Facial bones.
The cranial bones are form the cranial cavity, which encloses the brain and serves as an attachment site for the muscles of the head and neck.
- Parietal (2)
- Temporal (2)
- Frontal (1)
- Occipital (1)
- Ethmoid (1)
- Sphenoid (1)
Facial bones provide cavities for the sense organs (eyes, mouth, and nose), protect the entrances to the digestive and respiratory tracts, and serve as attachment points for facial muscles .
- Maxilla (2)
- Zygomatic (2)
- Mandible (1)
- Nasal (2)
- Platine (2)
- Inferior nasal concha (2)
- Lacrimal (2)
- Vomer (1)
The auditory ossicles consist of six bones: two malleus bones, two incus bones, and two stapes, one of each on each side and it transmit sounds from the air as vibrations to the fluid-filled cochlea.
- Malleus (2)
- Incus (2)
- Stapes (2)
The hyoid bone lies below the mandible in the front of the neck. It acts as a movable base for the tongue and is connected to muscles of the jaw, larynx, and tongue. The mandible articulates with the base of the skull, controlling the opening to the airway and gut.
The vertebral column, or spinal column, surrounds and protects the spinal cord, supports the head, and acts as an attachment point for the ribs and muscles of the back and neck.
- Cervical vertebrae (7)
- Thoracic vertebrae (12)
- Lumbar vertebrae (5)
- Sacrum (1)
- Coccyx (1)
The thoracic cage, also known as the rib cage, is the skeleton of the chest.It consists of the ribs, sternum, thoracic vertebrae, and costal cartilages .
The thoracic cage encloses and protects the organs of the thoracic cavity, including the heart and lungs.
It also provides support for the shoulder girdles and upper limbs, and serves as the attachment point for the diaphragm, muscles of the back, chest, neck, and shoulders. Changes in the volume of the thorax enable breathing.
- Sternum (1)
- Ribs (24)