THE HUMAN SKULL
Hy everyone, its i again. orr those who don't know me, i am Matthew Idungafa from Nigeria.
I am currently a 300level student in the Department Of Human Anatomy in The university of uyo, Akwaibom State.
I want to share an interesting lecture i had had today about the human skull(please Anatomical terms will be used here so bear with me Thanks.).
The skull has two parts Neurocranium and viscerocranium, Neurocranium is the bony part of the of the brain and its membranous covering.
The cranial meninges is also part of the neurocranium . The neurocranium contains the proximal parts of the cranial nerves and the
In adults, the neurocranium constitutes 8 bones. Out of this 8 bones, 4 are centred a a midline and 2 are paired.
The bones found on the midline are the temporal bones, and the parietal bones.
It is the neurocranium that forms the skull cap and also known as Calvaria(Skull Cap) and this neurocranium has a dome shape.
The bones that constitute the calvaria are part of the neurocranium
The bones making the calvaria are primarily flat bones and this includes frontal, parietal and the occipital bone. These bones are formed by intramembranous Ossification
of head mesenchyme from the neural crest.
The bones contributing to the cranial base are primarily irregularly bones with substantial flat portions formed by endochondrial ossification of cartilage and these bones include sphenoid and temporal bone.
Most common Calvaria bones are united by fibrous interlocking sutures. However,during childhood, some bones e.g sphenoid and occipital bone.
It is made up of fascial bones that mainly develops in the mesenchyme of the embyonic pharyngeal arches.It forms part of the mouth(Upper and lower jaw) nose/nasal cavity, and most of the orbit, the eye, the socket and the orbital cavities.It also consists of 15 irregular bones.
Mandible, Vomer and the etmoid are 3 single bones lying on the misline.
Six bones occuring as bilaterally paired bones Maxillae, inferior nasal Concha Zygomatic bone, palatine, nasal and lacrimal bone.
The maxillae and mandible houses the teeth. The maxillae constitutes the greater part of the upper skeleton for te upper jaw which is fixed to the cranial bone.
The mandible forms the skeleton of the lower jaw which is moveable because it articulates with its cranial base at the temporo-mandibular joint.
Several bones of the cranial are pneumatized bones which contain air spacing . Examples includesThe essence of the air spaces make the bones lighter
The total volume of these aire spaces increases with age i.e The older you are, the lighter your skull.
In the anatomical position, the cranium is oriented so that the inferior margin of the prbit and the superiort margin of te external acoustic meatus opening of the external acoustic meatus of both sides lie in the same horizontal plane. This standard craniometric reference is the orbito-meatal plane also known as FRANKFORT HORIZONTAL PLANE