Layers of Scalp

Question 1. Enumerate the layers of scalp. Give their blood supply, nerve supply & lymphatic drainage. (or) Describe the layers of scalp. Give its nerve supply, blood supply & lymphatic drainage. Add a note on its surgical anatomy. (or) Describe the layers of scalp. Add a note on its applied anatomy (or) Epicranial aponeurosis.
Answer:

• Scalp is the soft tissue which covers the calvaria of the skull

Scalp Layers:

S-Skin:

• S-Skin is outermost layer
• S-Skin is thick and hairy
• S-Skin is adherent to the epicranial
• S-Skin contains large number of hairs, sweat glands, sebaceous gland and is richly supplied by blood vessels

C-Superficial fascia:

• C-Superficial fascia is second layer
• C-Superficial fascia is more fibrous and dense in the center than periphery
• C-Superficial fascia contains large blood vessels & nerves of the scalp
• Thus C-Superficial fascia provides the proper medium for passage of vessels and nerves to the skin

A-Epicranial Aponeurosis:

• A-Epicranial Aponeurosis is freely movable

Scalp Attachments:

• Anteriorly: Insertion of frontalis
• Posteriorly: Insertion of occipitalis
• In between occipital bellies: Extrernal occipital protuberance & highest nuchal lines
• Each side: Attached to superior temporal line

L-Loose areolar tissue:

• L-Loose areolar tissue contains emissary veins devoid of valves
• This communicates the veins of scalp with intracranial venous sinuses

Extent:

• Anteriorly: Eyelids
• Posteriorly: Highest & superior nuchal lines
• Each side: Superior temporal lines

P-Pericranium: Fifth layer

• Loosely attached to bony surfaces
• Firmly adherent to bony sutures
• P-Pericranium: Fifth layer is the outer periosteum of skull Emissary vein

Blood Supply Arterial Supply:

Venous Drainage:

Lymphatic Drainage:

Nerve Supply:

Applied Anatomy According to layers:

Skin:

• Common site of sebaceous cyst due to abundant sebaceous glands
  • Superficial fascia
• Avulsed portion need not be cut away due to rich blood supply
• In open wound the vessels present in this layer are unable to retract & thus produce profuse bleeding
• Inflammation leads to little swelling but much pain
  • Loose areolar tissue
• Dangerous area of scalp as emissary vein open here
• If blood is collected in this layer, it leads to generalized swelling
  • Epicranial aponeurosis
• Wounds of scalp donot gape unless this layer is divided transversely
  • Pericranium
• Collection of fluid deep to it leads to cephalhaematoma