Scalp
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-525-6884
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
The scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly.
Layers
It is usually described as having five layers, which can be remembered with the mnemonic "SCALP":[1]
- S: The skin on the head from which head hair grows. It is richly supplied with blood vessels and can be subject to such conditions as dandruff and cutis verticis gyrata.
- C: Connective tissue. a thin layer of fat and fibrous tissue lies beneath the skin
- A: The aponeurosis (or galea aponeurotica) is the next layer. It is a tough layer of dense fibrous tissue which runs from the frontalis muscle anteriorly to the occipitalis posteriorly
- L: The loose areolar connective tissue layer provides an easy plane of separation between the upper three layers and the pericranium. 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. The loose areolar tissue in this layer is made up of random collagen I bundles, collagen III and is highly vascular and cellular. It will also be rich in glycosaminoglycans (GAGs) and will be constituted of more matrix than fibers.
- 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 (craniotomy).
Blood supply
The blood supply of the scalp is via four pairs of arteries, two from the external carotid and two from the internal carotid:
- internal carotid
- the supratrochlear artery to the midline forehead
- the supraorbital artery to the lateral forehead and scalp as far up as the vertex
- external carotid
- the superficial temporal artery which gives frontal and parietal branches to supply much of the scalp
- the occipital artery which runs from posteriorly to supply much of the back of the scalp.
Innervation
The scalp is innervated by the following:[1]
- Supratrochlear nerve and the supraorbital nerve from the ophthalmic division of the trigeminal nerve
- Greater occipital nerve (C2) posteriorly up to the vertex
- Lesser occipital nerve (C3) behind the ear.
- Zygomaticotemporal nerve from the maxillary division of the trigeminal nerve supplying the hairless temple
- Auriculotemporal nerve from the mandibular division of the trigeminal nerve
Role in aesthetics
The scalp plays an important role in the aesthetics of the face. Androgenic alopecia, or male pattern hair loss, is a common cause of concern to men. It may be treated by medication (eg finasteride) or hair transplantation with variable success. If the scalp is heavy and loose, a common change with aging, the forehead may be low, heave and deeply lined. The brow lift procedure aims to address these concerns.
Pathology
The scalp is a common site for the development of tumours including:
- epidermoid cyst
- pilar cyst
- actinic keratosis and squamous cell carcinoma
- basal cell carcinoma
- merkel cell tumours
See also
- Trichology -- the scientific study of hair and scalp
- Trichodynia -- burning scalp syndrome
Additional images
 Diagrammatic section of scalp. |
References
External links
- Histology at BU 08601ooa - "Integument: scalp, transverse"
- Histology at BU 08801ooa - "Integument: scalp"
- Norman/Georgetown lesson1
de:Kopfschwarteeo:Skalpo
fr:Cuir chevelu
it:cuoio capelluto
ko:머리가죽
nl:Kruinfi:Päänahka
sv:Skalp
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
