Cranium
The cranium is the skeleton of the head. The neurocranium is the bony case of the brain, and it is comprised of eight bones(frontal, ethmoid, sphenoid, occipital, 2 temporal, and 2 parietal). Most calvarial bones are united by fibrous interlocking sutures. A suture is the rigid joint that holds the bones together. The calvaria is the dome-like roof of the neruocranium. The frontal suture divides the fontal bones, the coronal suture seperates the frontal and parietal bones, the sagittal suture seperates the parietal bones, and the lambdoid suture seperates the parietal and temporal bones. The bones of the calvaria of a newborn infant are separate by membranous intervals named fontanelles. They largest occur between the angles of the flat bones. They include the anterior and posterior fontanelles and the sphenoid and mastoid fontanelles.
Cranial malformations occur when the cranial sutures close prematurely. Premature closure of the cranial sutures is called primary craniosynostosis, and it usually does not affect brain development. The cause is unknown, but genetics appear to play a role. The malformations are more common in males than in females. Cranial malformations are often associated with other skeletal anomalies. Scaphocephaly occurs when the sagittal suture closes prematurely and the anterior fontanelle is small or absent. Scaphocephaly results In a long, narrow, wedge shaped cranium. Plagiocephaly occurs when the coronal or lamboid suture closes prematurely, and the cranium is twisted and asymmetrical. Oxycephaly, or turricephaly, occurs when the coronal suture closes prematurely and the cranium results in a high, tower like shape. Oxcycephaly is more common in females.Scalp
The scalp consists of skin and subcutaneous tissue that cover the nerocranium. The scalp spans from the superior nuchal lines on the occipital bone to the supra-orbital margins of the frontal bone. The scalp extends over the temporal fascia to the zygomatic arches. There are five layers of the scalp. The first three layers are connected as a unit. The layers of the scalp, from superficial to deep, are Skin, Connective tissue, Aponeurosis, Loose connective tissue, and Pericranium.
There are many definitions and symptoms associated with scalp infections. There are different types of infections with different underlying causes. Ringworm is a common scalp infection. It is a superficial infection of the scalp, and is caused by a mold-like fungi called dermatophytes. Infection occurs when a particular type of fungus grows and multiplies anywhere on your skin, scalp, or nails. It is much more common in children. Symptoms include red, itchy patches on the scalp, bald areas, skin peeling, scaly skin, blisters, rash, and black dots on the scalp. Ringworm is an aggressive fungus. The rash is highly contagious and can spread on the body and to others. Ringworm is normally treated with over the counter products. A few of the other most common scalp conditions are red, burning, and itch scalp, dandruff, dry scalp, scalp dermatitis, eczema, scalp psoriasis, folliculitis, and stress related itching.
Facial Nerve
The facial nerve, or Cranial Nerve VII, has both sensory and motor function. The motor root supplies the muscles of facial expression, including the superficial muscle of the neck, auricular muscles, scalp muscles, and others. The main trunk of the facial nerve runs anteriorly, and gives rise to five terminal branches, which are the temporal, zygomatic, buccal, marginal mandibular, and cervical. The names of the branches refer to the regions that they supply.
Bell’s palsy is a disorder that results in weakness or paralysis of some or all of the facial muscles on an affected side. Injury to the facial nerve or its branches results in Bell’s palsy. The affected area sags, and facial expression is distorted, making it appear passive or sad. There may be different symptoms associated depending on the location and amount of the injury on the facial nerve. Some symptoms include impaired speech, inability to blow, displacement of the mouth causing food and saliva to drip out, inability to chew on one side resulting in food accumulation, eversion of the lower eyelid, and inadequate lubrication of the eye resulting in vulnerability to ulceration and impaired vision. The specific cause of Bell’s palsy is unknown.Sources:
Clinically Oriented Anatomy
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