1. Head & Neck Unit – Lecture 4 د. حيدر جليل الأعسم
The Scalp
Head & Neck Unit – Lecture 4
د. حيدر جليل الأعسم

2. The scalp
part of the head that extends from superciliary arches anteriorly to the external occipital protuberance & superior nuchal lines posteriorly. Laterally, it continues to the zygomatic arch.
Layers of scalp:
five layers, the first three layers are intimately bound together and move as a unit (Scalp Proper)
S- Skin
C- Connective tissue (dense) (Scalp Proper)
A- Aponeurotic layer
L- Loose connective tissue
P- Pericranium

3. Muscle of the Scalp (Occipitofrontalis muscle)
It moves the scalp proper, wrinkle the forehead, and raise the eyebrows. It Has 2 bellies:
Frontal belly: (origin) skin & superficial fascia of the eyebrows (insertion) aponeurotic tendon & is innervated by temporal branches of the facial nerve.
Occipital belly: (origin) superior nuchal line of occipital bone & mastoid process of temporal bone (insertion) aponeurotic tendon & is innervated by posterior auricular branch of the facial nerve.

4. Scalp Innervation Two main sources: 1- Cranial nerves:
(Ant. to ear & vertex)
By Trigeminal nerve
2- Cervical nerves:
(Post. to ear & vertex)
By C2 & C3 nerves.

5. Scalp Innervation Trigeminal branches: (Ant. to ears & vertex)
A- Supratrochlear nerve:
front of the forehead near the midline;
B- Supra-orbital nerve: the scalp as far back as the vertex of the head;
C- Zygomaticotemporal nerve:
the scalp over a small anterior area of temporal region (temple)
D- Auriculo-temporal nerve: the scalp over the temporal region.

6. Scalp Innervation Cervical nerves (C2 &C3)
(Posterior to ears & vertex)
A- Great auricular nerve:
small area of the scalp just posterior to the ear & angle of mandible.
B- Lesser occipital nerve: the scalp posterior & superior to ear
C- Greater occipital nerve: posterior scalp as far as the vertex;
D- Third occipital nerve: a small area of the lower part of the scalp.

7. Arterial Supply Internal Carotid Artery Branches:
The scalp has rich blood supply;
It arterial supply is from internal and external carotid arteries.
Internal Carotid Artery Branches:
1- Ophthalmic artery:
2- Supratrochlear artery
3- Supra-orbital arteries
As fas as the vertex.
External Carotid Artery Branches:
1- Posterior auricular artery (smallest)
area of the scalp posterior to the ear;
2- Pre-auricular artery (superficial temporal artery (a terminal branch of ECA)in front of the ear & supplies most of the lateral aspect of scalp.
3- Occipital artery: large part of the posterior aspect of the scalp.

8. Venous Drainage Usually follows the arteries: 1- Supratrochlear vein
2- Supra-orbital vein
3- Pre-auricular vein (superficial temporal vein)
3- Posterior auricular vein
4- Occipital vein

9. Lymphatic drainage
Lymphatics in the occipital region initially drain to occipital nodes then into the upper deep cervical nodes.
Lymphatics from the upper part of the scalp drain in two directions:
1- Posterior to the vertex: to posterior auricular nodes (mastoid nodes) then into the upper deep cervical nodes;
2- Anterior to the vertex: to pre-auricular nodes (parotid nodes).
Lymphatics from the forehead to the submandibular nodes through efferent vessels that follow the facial artery.

10. Good Luck