1. Scalp:Â
5 layers S - the Skin on head from which head hair grows
C - Connective tissue. A dense subcutaneous layer of fat and fibrous tissue that lies beneath the skin, containing the nerves and vessels of the scalp. A - The Aponeurosis called epicranial aponeurosis (Galea Aponeurotica). It is a tough layer of dense fibrous tissue which runs from the frontalis muscle anteriorly to the occipitals posteriorly. L - The loose areolar connective tissue. In scalping the scalp is torn off through this layer. It also provides a plane of access in craniofacial surgery and neurosurgery. This layer is sometimes referred to as the “danger zone” because of the ease by which infectious agents can spread through it to emissary veins which then drain into the cranium. P - The pericranium is the periosteum of the skull bones and provides nutrition to the bone and the capacity for repair. It may be lifted from the bone to allow removal of bone windows
2. Skull: It supports the structures of the face and provides a protective cavity for the brain. The skull is composed of 2 parts:
- the cranium - the mandibleÂ
The human skull is generally considered to consist of 22 bones—8 cranial bones and 14 facial skeleton bones. In the neurocranium these are the occipital bone, 2 temporal bones, 2 parietal bones, the sphenoid, ethmoid and frontal bones.
The bones of the facial skeleton are the vomer, 2 nasal conchae, 2 nasal bones, 2 maxilla, the mandible, 2 palatine bones, 2 zygomatic bones, and 2 lacrimal bones. Some sources count a paired bone as one, or the maxilla as having two bones (as its parts); some sources include the hyoid bone or the three ossicles of the middle ear but the overall general consensus of the number of bones in the human skull is the stated twenty-two. 3. Dura mater:
Thick membrane that is the outermost of the three layers of the meninges. The dura surrounds the brain and the spinal cord and is responsible for keeping in the cerebrospinal fluid. 4. Arachnoid 2nd layer of the meninges 5. Pia mater
3rd layer of meninges
6. Subarachnoid space
Space between arachnoid mater and pia mater It is occupied by spongy tissue consisting of trabecular (delicate connective tissue filaments that extend from the arachnoid mater and blend into the pia mater) and intercommunicating channels in which the cerebrospinal fluid (CSF) is contained. 7. Cerebral cortex
The Cerebral Cortex is made up of tightly packed neurons and is the wrinkly, outermost layer that surrounds the brain. It is also responsible for higher thought processes including speech and decision making . The cortex is divided into four different lobes, the frontal, parietal, temporal, and occipital, which are each responsible for processing different types of sensory information.Â
