View source for Scalp

{{Infobox Anatomy |
  Name         = {{PAGENAME}} |
  Latin        = |
  GraySubject  = 105 |
  GrayPage     = 378 |
  Image        = Double_cowlick.jpg |
  Caption      = |
  Image2       = |
  Caption2     = |
  Precursor    = |
  System       = |
  Artery       = [[supratrochlear artery|supratrochlear]], [[supraorbital artery|supraorbital]], [[superficial temporal artery|superficial temporal]], [[occipital artery|occipital]] |
  Vein         = [[superficial temporal vein|superficial temporal]], [[posterior auricular vein|posterior auricular]], [[occipital vein|occipital]] |
  Nerve        = [[supratrochlear nerve|supratrochlear]], [[supraorbital nerve|supraorbital]], [[greater occipital nerve|greater occipital]], [[lesser occipital nerve|lesser occipital]] |
  Lymph        = [[occipital lymph nodes|occipital]], [[mastoid lymph nodes|mastoid]] |
  MeshName     = Scalp  |
  MeshNumber   = A01.456.810  |
  DorlandsPre  = s_03 |
  DorlandsSuf  = 12721502  |
}}
{{CMG}}

{{EH}}

==Overview==
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":<ref>{{MedicalMnemonics|258|||}}</ref>

* 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:<ref>{{MedicalMnemonics|2046|||}}</ref>
* [[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 nerve|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==
<gallery>
 Image:Gray1196.png|Diagrammatic section of scalp.
</gallery>

==References==
<references/>

{{Head and neck general}}

==External links==
* {{BUHistology|08601ooa}} - "Integument: scalp, transverse"
* {{BUHistology|08801ooa}} - "Integument: scalp"
* {{NormanAnatomy|lesson1}}

[[category:Head and neck]]
{{SIB}}
[[de:Kopfschwarte]]
[[es:Cuero cabelludo]]
[[eo:Skalpo]]
[[fr:Cuir chevelu]]
[[it:cuoio capelluto]]
[[ko:머리가죽]]
[[nl:Kruin]]
[[pt:Couro cabeludo]]
[[fi:Päänahka]]
[[sv:Skalp]]

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