DEFINITION

1
DEFINITION

• It is the soft tissue covering the Norma
  Verticalis ( vault of the skull) .

2
EXTENSION

• It extends from the superciliary arches
  anteriorly to the external occipital protuberance
  posteriorly.
• Laterally , it is continuous to the zygomatic
  arch.

3
LAYERS

• The scalp is formed of (Five) layers.
• They can be defined by the word itself
• S Skin.
• C Connective tissue.
• A Aponeurotic layer.

4
LAYERS

• L Loose connective tissue.
• P - Periosteum

5
SCALP PROPER

• It is the first three layers that are tightly
  held together to form a single unit.
• It is the tissue torn away during serious
  scalping injuries.

6
SKIN

• It is thick hairy with numerous sebaceous and
  sweat glands.
• Obstruction of the ducts of the sebaceous glands
  by secretions form Sebaceous cysts.
• They move with the scalp.

7
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
  embedded within it.

8
APONEUROTIC LAYER

• It is a thin and tendinous sheet that unites the
  frontal and occipital bellies of
  occipitofrontalis muscle.
• It is attached laterally to the temporal fascia.

9
OCCIPTOFRONTALIS MUSCLE

• It has a frontal belly anteriorly,
• An occipital belly posteriorly, and an
  aponeurotic tendon (galea aponeurotica)
  connecting the two bellies.

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FRONTAL BELLIY

• It arises from the anterior part of the
  aponeurosis.
• It is inserted into the skin of the eye brows.

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FRONTAL BELLY

• It elevates the eyebrows giving the face a
  surprised looking and produces transverse
  wrinkles of the forehead.

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OCCIPTAL BELLY

• It arises from the highest nuchal lines on the
  occipital bone.
• It passes superiorly to be
• inserted into the aponeurosis.

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NERVE SUPPLY

• It is through the terminal branches of the Facial
  nerve.
• The frontal belly is supplied by the temporal
  branch.
• The occipital belly is supplied by the posterior
  auricular branch.

14
LOOSE AREOLAR TISSUE

• It occupies the subaponeurotic space.
• It contains few arteries and the important
  emissary veins.

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DANGEROUS LAYER

• The (4th ) layer of the scalp is the dangerous
  layer because pus or blood spreads easily in it.
• Infection in this layer can spreads into the
  bones through the diploic veins causing
  osteomyelitis

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SCALP INFECTIONS

• It can spread through the emissary veins to the
  intracranial venous sinuses to cause Venous Sinus
  thrombosis.

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SCALP INFECTIONS

• An infection in the scalp can not extend
  posteriorly into the neck because of the
  attachment of occipitalis muscle to the occipital
  and temporal bones.

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SCALP INFECTIONS

• Nor laterally because of attachment of the
  aponeurosis to the temporal fascia.

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SCALP INFECTIONS

• An infection or fluid can spreads only into the
  eye lids and the root of the nose because of the
  attachment of the frontalis into the skin and not
  to the bone.

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PERICRANIUM

• It is the deepest layer.
• It is the periosteum on the outer surface of
  the calvaria.
• At the sutures it becomes continuous with the
  periosteum on the outer surface of the bones.

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SENSORY NERVE SUPPLY

• It is from two main sources
• Trigeminal nerve.
• Cervical nerves (2ND 3RD ).
• Depending on whether it is anterior or posterior
  to the ears.

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ANTERIOR TO THE EAR

• (A) Ophthalmic nerve
• 1.Supratrochlear
• It exits from the orbit.
• It ascends superiorly to supply the forehead and
  scalp as far as the midline (vertex).

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ANTERIOR TO THE EAR

• 2. Supraorbital
• It exits from the orbit through the supraorbital
  notch.
• It passes superiorly to the scalp as far as the
  vertex.

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ANTERIOR TO THE EAR

• (B) Maxillary nerve
• 3. Zygomaticotemporal nerve
• It exits through a small foramen in the zygomatic
  bone.
• It supplies a small anterior area of the temple.

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ANTERIOR TO THE EAR

• (C) Mandibular nerve
• 4. Auriculotemporal nerve
• It passes just anterior to the ear.
• It supplies the scalp over the temporal region.

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POSTERIOR TO THE EAR

• 1. Great auricular
• It supplies a small area posterior to the scalp.
• 2. Lesser occipital it supplies the area
  posterior and superior to the scalp.

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POSTERIOR TO THE EAR

• 3. Greater occipital (posterior ramus of C 2).
• 4. Third occipital (posterior ramus of C 3).

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ARTERIAL SUPPLY

• The scalp has a rich blood supply.
• The arteries take origin from
• External carotid artery.
• Ophthalmic artery.
• The arteries freely anastomose with each other.

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OPTHALMIC ARTERY

• 1. Supratrochlear.
• 2. Supraorbital.
• They accompany the corresponding nerves to supply
  the scalp as far as the vertex.

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EXTERNAL CAROTID ARTERY

• From the posterior aspect
• 1. Posterior auricular
• It is the smallest branch.
• It supplies the scalp posterior to the ear.

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EXTERNAL CAROTID ARTERY

• 2.Occipital
• It accompanies the greater occipital nerve.
• It passes through the musculature of the back
• It supplies a large area of the back of the scalp.

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EXTERNAL CAROTID ARTERY

• 3. Superficial temporal artery
• It is the smaller terminal branch of the external
  carotid.
• It divides into anterior and posterior branches.
• It supplies almost the entire lateral aspect of
  the scalp.

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VEINS OF THE SCALP

• Supratrochlear supraorbital veins
• They drain the anterior part of the scalp.
• They communicate with the ophthalmic veins in the
  orbit.
• Inferiorly they participate in the formation of
  the angular vein (upper tributary of the (Facial
  vein).

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VEINS OF THE SCALP

• Superficial temporal vein
• It drains the entire lateral area of the scalp.
• Inferiorly, it joins the maxillary vein to form
  the Retromandibular vein.

35
VEINS OF THE SCALP

• Posterior auricular vein
• It drains the area posterior to the ear.
• It unites with the posterior division of the
  retromandibular vein to form the External Jugular
  vein.

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VEINS OF THE SCALP

• Occipital vein
• It drains into the suboccipital venous plexus.
• The plexus drains into the vertebral veins or the
  internal jugular vein.

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VEINS OF THE SCALP

• Veins of the scalp are connected to the Diploic
  veins and to the Intracranial venous sinuses
  through the valveless Emissary veins.

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LYMPH DRAINAGE

• Lymph vessels follow the arteries.
• From the anterior part and forehead drain into
  Submandibular nodes.

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LYMPH DRAINAGE

• Lateral part (above the ear) to
• Superficial parotid (preauricular).
• Lateral part (behind the ear) to
• Mastoid nodes.
• Back of the scalp to occipital nodes.

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SCALP LACERATIONS

• Wounds of the scalp bleed profusely because of
• 1. The abundant arterial anastomoses.

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SCALP LACERATIONS

• 2. Arteries do not retract when lacerated because
  they are held open by the dense connective tissue
  in layer (2).
• Local pressure is the only way to stop bleeding.

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SCALP LACERATIONS

• Deep scalp wounds needs to be sutured because
  they gape widely when the epicranial aponeurosis
  is divided.
• This because of the tension of the aponeurosis
  produced by the tone of the occipitofrontalis
  muscle.