5. Boundaries of the scalp
Anteriorly
Superciliary Arches of the Frontal Bones
Posteriorly
External Occipital Protuberance & Superior Nuchal
Lines of the Occipital Bone
Laterally
Continues inferiorly to the Zygomatic Arches
The layers of skin and subcutaneous tissue that cover the bones of the cranial vault are referred to as the
scalp.
7. Layers of the scalp
1. S - Skin
2. C - Connective Tissue (dense)
3. A - Aponeurosis
4. L - Loose Connective Tissue
5. P - Pericranium
‘Scalp proper’
● 3 layers tightly bound together
and move as a unit
8. Skin
● Outermost layer
● Has many hair follicles and sebaceous glands, making it a typical location for sebaceous
cysts.
Connective tissue
● Dense
● Connects the skin to the aponeurosis.
● It's well-vascularized (arteries & veins) and innervated (nerves).
● Its blood vessels are very tightly bound to the connective tissue. Hence, if lacerated,
they are unable to properly constrict and the scalp becomes a source of excessive
bleeding.
Layers of the scalp
9. Aponeurosis (epicranial)
A thin, tendon-like structure that connects the occipital belly
posteriorly and frontal belly anteriorly to form the occipitofrontalis
muscle
Layers of the scalp
Part of
Muscle Origin Insertion
Innervatio
n Action
Frontal Belly
Epicranial
Aponeurosis
Skin &
subcutaneous
tissue of
eyebrows and
forehead
Temporal
branch of
facial nerve
Elevates eyebrows;
Wrinkles skin of
forehead; Protracts
scalp
Occipital Belly
Lateral ⅔ of
superior
nuchal line
Epicranial
Aponeurosis
Posterior
auricular
branch of
facial nerve
Retracts scalp
10. Loose Areolar Connective Tissue
● A thin layer of connective tissue that separates the skull's periosteum from the epicranial
aponeurosis.
● It has many blood vessels, including emissary veins that connect the scalp veins to the
diploic veins and intracranial venous sinuses.
● Facilitates movement of scalp proper over calvaria
Periosteum
● The outer layer of the skull bones is known as the periosteum. At the suture lines, it merges
with the endosteum.
Layers of the scalp
12. ● The scalp receives a rich arterial supply via the external carotid artery and ophthalmic
artery (a branch of the internal carotid artery)
● These arteries anastomose freely with each other within the dense connective tissue. (Layer
2 of the scalp)
● The branches of the external carotid artery involved are:
○ Superficial temporal artery- supplies the frontal and temporal regions.
○ Posterior auricular artery- supplies the area superiorly and posteriorly to the auricle.
○ Occipital artery- supplies back of the scalp
Arterial Supply of the scalp
13. Diagram showing the branches of the external carotid artery that supply the scalp
14. ● The branches of the Opthalmic artery (branch of the Internal Carotid Artery) are:
○ Supraorbital artery- larger than supratrochlear A.; supplies the front of the scalp up to
the vertex. It anastomosis with the superficial temporal artery
○ Supratrochlear artery- supplies the forehead and scalp.
Arterial Supply of the scalp
17. Venous Drainage
The veins which drain the scalp are:
● Supratrochlear and Supraorbital veins – drain the
anterior portion of the scalp (superciliary arches to
the vertex of the head). These two veins
communicate with the ophthalmic vein and unite to
form the angular vein.
● Superficial temporal vein – drain the lateral portion
of the scalp. It descends anteriorly to the auricle and
joins the maxillary vein to form the retromandibular
vein.
18. ● Posterior auricular vein- drain the scalp
posterior to the ear and empties into a branch
of the retromandibular vein.
● Occipital vein – drains the area of the scalp
from the external occipital protuberance and
superior nuchal line to the vertex of the head.
It passes in the posterior neck to join in the
formation of the plexus of veins in the
suboccipital triangle.
20. ● There are no lymph nodes in the scalp.
● The lymphatics in the occipital region initially drain to occipital nodes (at the
base of the skull). Further along, it drains into the upper deep cervical lymph
nodes.
Lymphatics from the upper part of the scalp drain into two directions:
● Posterior to the vertex of the head, they drain into the mastoid nodes.
(posterior to the ear near the mastoid process of the temporal bone). Efferent
vessels from these nodes drain into the upper deep cervical nodes.
● Anterior to the vertex of the head, they drain to preauricular and parotid
nodes anterior to the ear on the surface of the parotid gland.
Lymphatic Drainage
21. ● Finally, there are some lymphatic drainage from the
forehead to the submandibular nodes through the
efferent vessels that follow the facial artery.
Lymphatic Drainage
Diagram showing the lymphatic
drainage of the scalp
23. The scalp is innervated by two main nerve supplies:
● the Trigeminal nerve (CN V)
● the Spinal cutaneous nerves (C2 and C3).
Trigeminal nerve (CN V) innervates the scalp anterior to the auricles.
Spinal cutaneous nerves (C2 and C3) innervates the scalp posterior
to the auricles.
Innervations of the SCALP
24. 1. Supratrochlear nerve – branch of CN V1 which
innervates the anteromedial forehead.
1. Supraorbital nerve – branch of CN V1 which
innervates a large portion of the scalp between the
anterolateral forehead and the vertex.
1. Zygomaticotemporal nerve – branch of CN V2 ,this
innervates the temple.
1. Auriculotemporal nerve- branch of CN V3 which
innervates skin anterosuperior to the auricle.
Innervation of the scalp anterior to the
auricle:
25. Innervation of the scalp posterior to the
auricle:
1. Lesser occipital nerve – derived from the anterior ramus
of C2 and innervates the skin posterior to the ear.
1. Greater occipital nerve – derived from the posterior
ramus of C2 and innervates the skin of the occipital region
extending to the vertex.
1. Great auricular nerve – derived from the anterior rami of
C2 and C3 and innervates the skin posterior to the ear.
1. Third occipital nerve – derived from the posterior ramus
of C3 and innervates the skin of the inferior occipital
region.
26. REFERENCES
● Moore, K. L., Dalley, A. F., & A M R Agur. (2014). Moore clinically oriented anatomy (pp. 843–859). Wolters
Kluwer Health/Lippincott Williams & Wilkins.
● Drake, R. L., Vogl, W., Mitchell, A. W. M., Gray, H., Tibbitts, R., Richardson, P., & Horn, A. (2020). Gray’s
Anatomy for Students (4th ed., pp. 922–927). Elsevier.
● Harris, C. M. (2022, December 22). Scalp Anatomy: Structure, Nerve Supply, Arterial Supply. Medscape.com;
Medscape. https://emedicine.medscape.com/article/834808-overview?icd=login_success_gg_match_norm#a1
● The Scalp - Layers - Innervation - Blood Supply - TeachMeAnatomy. (2016). Teachmeanatomy.info.
https://teachmeanatomy.info/head/areas/scalp/
● SkinKraft. (2020, June 26). The 5 Layers Of Scalp Explained. SkinKraft.
https://skinkraft.com/blogs/articles/layers-of-scalp
27. CREDITS: This presentation template was created by Slidesgo, and
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Editor's Notes
For additional reading see:
The 5 Layers Of Scalp Explained. (2021, December 8). SkinKraft. https://skinkraft.com/blogs/articles/layers-of-scalp
TeachMeAnatomy. (2020, November 22). The scalp - layers - innervation - blood supply - TeachMeAnatomy. https://teachmeanatomy.info/head/areas/scalp/
The lymphatic vessels of the face accompany other facial vessels. Superficial lymphatic vessels accompany veins, and deep lymphatics accompany arteries.
The lymphatic vessels of the face accompany other facial vessels. Superficial lymphatic vessels accompany veins, and deep lymphatics accompany arteries.