Skull.

 Skull.

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Introduction:

• The skull rests on the upper end of the vertebral column and its bony structure is divided into two parts:

• The cranium and 

• The face. 

• The cranial bones compose the top and back of the skull and enclose the brain. 

• The facial skeleton, as its name suggests, makes up the face of the skull.

Bones of Skull

Cranium:

• The cranium is formed by a number of flat and irregular bones that provide a bony protection for the brain. 

• It has a base upon which the brain rests and a vault that surrounds and covers it.

• It is made up of eight bones as follows,

• 1 frontal bone : Front 

• 2 parietal bones: Top

• 2 temporal bones: Side 

• 1 occipital bone: Back 

• 1 sphenoid bone: Internal 

• 1 ethmoid bone. Internal

Face:

• The skeleton of the face is formed by 14 bones in addition to the frontal bone.

• Facial skeleton form the entrances to the respiratory and digestive tracts.

• 2 zygomatic or cheek bones.

• 2 maxilla.

• 2 nasal bones.

• 2 lacrimal bones.

• 1 vomer.

• 2 palatine bones.

• 2 inferior conchae.

• 1 mandible.

• Zygomatic (2) – 

• forms the cheek bones of the face and articulates with the frontal, sphenoid, temporal and maxilla bones.

• Lacrimal (2) – 

• the smallest bones of the face. They form part of the medial wall of the orbit.

• Nasal (2) – 

• two slender bones that are located at the bridge of the nose.

• Inferior nasal conchae (2) – 

• located within the nasal cavity, these bones increase the surface area of the nasal cavity, thus increasing the amount of inspired air that can come into contact with the cavity walls.

• Palatine (2) – 

• situated at the rear of the oral cavity and forms part of the hard palate.

• Maxilla (2) – 

• comprises part of the upper jaw and hard palate.

• Vomer (1) – 

•  forms the posterior aspect of the nasal septum.

• Mandible (jaw) (1) –

• articulates with the base of the cranium at the temporomandibular joint (TMJ).

Sutures of the Skull:

• Sutures are a type of fibrous joint that are unique to the skull. 

• They are immovable and fuse completely around the age of 20.

• The main sutures in the adult skull are:

• Coronal suture – fuses the frontal bone with the two parietal bones.

• Sagittal suture – fuses both parietal bones to each other.

• Lambdoid suture – fuses the occipital bone to the two parietal bones.

Commonly Asked Questions:

1. Draw a well labelled diagram of Human Skull.

2. Name facial and cranial bones.

3. Write in short about sutures of skull.