3. Defn / Description
It is the soft tissue covering of the norma verticalis (vault of the
skull)
It extends:
• Posteriorly, from the superior nuchal lines of the occipital bone
• Anteriorly, from the supraorbital margin of the frontal bone
• Laterally, over the temporal fascia, to the zygomatic arches
4. SCALP
S – SKIN (Layer 1)
C – CONNECTIVE TISSUE (DENSE) (L2)
A – APONEUROSIS (GALEA) (L3)
L – LOOSE CONNECTIVE TISSUE (L4)
P – PERICRANIUM (L5)
7. Layer 1 - Skin
• It is thick, hairy with numerous sebaceous and sweat glands.
• Obstruction of the ducts of the sebaceous glands by secretions form
Sebaceous cysts.
• Dandruff – dermatology
• Hair transplants
8.
9. Layer 2 – Connective tissue
• It is a fibro-fatty layer which is adherent to the skin and to the underlying
aponeurosis by fibrous septa.
• It is richly supplied with vessels and nerves that run within it. The arteries freely
anastomose with each other. Alternative/collateral blood supply.
• Wounds of the scalp bleed profusely because of:
1. The abundant arterial anastomoses.
2. Arteries do not retract when lacerated because they are held open by the dense
connective tissue.
10. Layer 3 – Epicranius and Aponeurosis
• Galea aponeurotica
• Deep scalp wounds gape widely when the epicranial aponeurosis is divided
due to tension of the aponeurosis produced by the tone of the occipito-
frontalis muscle.
11. Layer 4 – Loose connective tissue
Sub-aponeurotic space
• limited in front and behind by
the origins of the occipitofrontalis
muscle
• extends laterally as far as the
attachment of the aponeurosis to
the temporal fascia
• Has loose areolar tissue with
important emissary veins
12. Importance of layer 4
Dangerous layer:
• Scalp infections can spread through the emissary veins to the intracranial
venous sinuses to cause Venous Sinus thrombosis.
(Emissary veins - valveless veins that connect the superficial veins of the scalp with the diploic veins of the skull
bones and, through them, with the intracranial venous sinuses).
• Blood (sub-aponeurotic haematoma) or pus can spreads to the eye lids and
the root of the nose because of the attachment of the frontalis into the skin
and not to the bone
14. Layer 5 - Pericranium
• It is the periosteum covering the outer surface of the skull bones
• At the sutures between individual skull bones, the periosteum on the outer
surface of the bones is continuous with the periosteum on the inner surface
of the skull bones
• Sub-periosteal/cephalo-haematomas