Scalp & Superficial Temporal Regiion

SCALP & SUPERFICIAL TEMPORAL REGIION


SCALP & SUPERFICIAL TEMPORAL REGIION

SCALP: Soft tissue which covers the clavira of skull. 

LAYERS OF SCALP:  CONSISTS OF FIVE LAYERS

1. Skin:

  • Thick and hairy.
  •  Adherent to the epicranial aponuerosis through the dense superficial fascia.

2. Close network of Connective tissue (superficial fascia):

  • Contain vessels and nerves; highly vascular layer.
  • The scalp gapes when cut, & blood vessels are held open by the dense connective tissue, resulting in bleeding that should be arrested by pressure.

3. Aponuerosis (galea aponeurotica) with occipitofrontalis muscles:

  • It is freely movable on the pericranium along with the overlying and adherent scalp and fascia.
  • On each side it is attached to the superior temporal lines.
  • Anteriorly, it receives the insertion of the frontalis.
  • Posteriorly, receives insertion of the occipital bellies.

4. Loose areolar (Subaponuerotic) tissue:

  • Containing the emissery veins & allowing free movement of layers 1 to 3 as a unit.
  • Layer 4 is a “dangerous area” because it allows spread of infection even, by way of the emissery veins, to intracranial structures.

5. Pericranium (outer periosteum of skull):

  • Loosely attached to the surface of the bones, but is firmly adherent to the sutures where the sutural ligaments bind the pericranium to the endocranium.
BLOOD SUPPLY:
   
ARTERIAL SUPPLY: 
  • IN FRONT OF AURICLE-
  1. Supratrochlear
  2. Supraorbital
  3. Superficial temporal arteries
  • BEHIND THE AURICLE-
  1. Posterior auricular
  2. Occipital arteries
 VENOUS DRAINAGE:
  • Supratrochlear+ supraorbital→ angular vein→ FACIAL VEIN.
  • Superficial temporal+ Maxillary vein→ RETROMANDIBULAR VEIN→ divides into anterior and posterior division.
  • Anterior division+Facial vein→common facial veins→ INTERNAL JUGULAR VEIN.
  • Posterior division+Posterior auricular vein→External jugular vein→SUBCLAVIAN VEIN.
  • Occipital vein->suboccipital plexus

LYMPHATIC DRAINAGE:

  • Lymph vessels from the frontal region above the root of the nose drain into the submandibular nodes.
  • Vessels from rest of the forehead,temporal region,upper half of the lateral auricular aspect and anterior wall of the external acoustic meatus drain into superficial parotid nodes, just anterior to the tragus ,on or deep to the parotid fascia.
  • The occipital region of the scalp is drained by the occipital nodes,and partly by the vessel that runs along the posterior borderof the sternocleidomastoid to the lower deep cervical nodes
  • A strip of the scalp above the auricle drains to the upper deep cervical and retro auricular nodes.
  • The retro auricular in turn drain to deep cervical.

NERVE SUPPLY:

  • Scalp supplied by ten nerves on each side.
  • Five nerves (4 sensory and one motor) enter scalp in front of the auricle.
  • Remaining five (4 sensory one motor) enter behind the auricle.                                                   

IN FRONT OF AURICLE (SENSORY)

BEHIND THE AURICLE (SENSORY)

SUPRATROCHLEAR branch of the Frontal (Opthalmic div. of trigeminal nerve)

 POSTERIOR DIVISION OF GREATER  AURICULAR (C2,C3) from cervical plexus

SUPRAORBITAL branch of Frontal

(Opthalmic division of trigeminal nerve)

LESSER OCCIPITAL (C2), from cervical plexus

ZYGOMATICOTEMPORAL, branch of zygomatic   nerve (Maxillary division of trigeminal nerve)

GREATER OCCIPITAL (C2, dorsal ramus)

AURICULOTEMPORAL branch of mandibular division of trigeminal nerve.

THIRD OCCIPITAL (C3, dorsal ramus)

(MOTOR)

(MOTOR)

TEMPORAL BRANCH OF FACIAL NERVE

POSTERIOR AURICULAR BRANCH OF FACIAL      NERVE

CLINICAL ANATOMY:

  1. SEBACEOUS CYST due to collection of sebum as a result of obstruction of sebaceous cyst, secondary infection may sets in.
  2. Scalp wounds bleed profusely-  because elastic fibres of underlying galea aponuerotica prevent initial vessel retraction, the wounds may be associated with significant blood loss which can result in clinical shock.
  3. Scalp flaps -used in craniofacial surgery for correction of congenital deformity,for release of craniosynostosis, treatment of craniofacial fractures and for repair of scalp defects after excision of skin tumors.
  4. Hemostasis in scalp wound is best achieved by pressure over wound.
  5. When suturing scalp lacerations, it is essential to control all bleeding points before repairing the scalp itself.
  6. It is necessary to tie off larger arterioles and veins and use bipolar diathermy to control smaller arterioles and veins.
  7. Repair of scalp require full thickness tension sutures because galea aponuerotica will otherwise gape as the occipital and frontal bellies contract.
  8. Lacerated wound appears as incised wound in scalp.
  9. Failure to control bleeding points  can result in significant hematomas, often subgaleal, leading to breakdown of the orginal wound and sometimes necessitating surgical drainage.

Exam Question

  • Subcutaneous tissue is the highly vascular layer of scalp.
  • Hemostasis in scalp wound is best achieved by direct pressure over wound.
  • Lacerated wound appears as incised wound in scalp.
  • Normal value of fetal scalp pH- 7.25-7.35.
  • Fetal scalp blood Ph is used to determine Fetal hypoxia.
  • EEG rhythm recorded from the surface of the scalp during REM sleep is Beta.
  • Collection of sero-sanguineous fluid in the scalp is limited to individual bone.
  • LOOSE SUBAPONEUROTIC TISSUE (Layer 4) is a “dangerous area” because it allows spread of infection even, by way of the emissery veins, to intracranial structures.
SCALP: Soft tissue which covers the clavira of skull.

 LAYERS OF SCALP:  CONSISTS OF FIVE LAYERS

1. Skin:

  • Thick and hairy.
  •  Adherent to the epicranial aponuerosis through the dense superficial fascia.

2. Close network of Connective tissue (superficial fascia):

  • Contain vessels and nerves; highly vascular layer.
  • The scalp gapes when cut, & blood vessels are held open by the dense connective tissue, resulting in bleeding that should be arrested by pressure.

3. Aponuerosis (galea aponeurotica) with occipitofrontalis muscles:

  • It is freely movable on the pericranium along with the overlying and adherent scalp and fascia.
  • On each side it is attached to the superior temporal lines.
  • Anteriorly, it receives the insertion of the frontalis.
  • Posteriorly, receives insertion of the occipital bellies.

4. Loose areolar (Subaponuerotic) tissue:

  • Containing the emissery veins & allowing free movement of layers 1 to 3 as a unit.
  • Layer 4 is a “dangerous area” because it allows spread of infection even, by way of the emissery veins, to intracranial structures.

5. Pericranium (outer periosteum of skull):

  • Loosely attached to the surface of the bones, but is firmly adherent to the sutures where the sutural ligaments bind the pericranium to the endocranium.
BLOOD SUPPLY:
   
ARTERIAL SUPPLY:
  • IN FRONT OF AURICLE-
  1. Supratrochlear
  2. Supraorbital
  3. Superficial temporal arteries
  • BEHIND THE AURICLE-
  1. Posterior auricular
  2. Occipital arteries

VENOUS DRAINAGE:

  • Supratrochlear+ supraorbital→ angular vein→ FACIAL VEIN.
  • Superficial temporal+ Maxillary vein→ RETROMANDIBULAR VEIN→ divides into anterior and posterior division.

Anterior division+Facial vein→common facial veins→ INTERNAL JUGULAR VEIN.

Posterior division+Posterior auricular vein→External jugular vein→SUBCLAVIAN VEIN.

Occipital vein->suboccipital plexus

LYMPHATIC DRAINAGE:

  • Lymph vessels from the frontal region above the root of the nose drain into the submandibular nodes.
  • Vessels from rest of the forehead,temporal region,upper half of the lateral auricular aspect and anterior wall of the external acoustic meatus drain into superficial parotid nodes, just anterior to the tragus ,on or deep to the parotid fascia.
  • The occipital region of the scalp is drained by the occipital nodes,and partly by the vessel that runs along the posterior borderof the sternocleidomastoid to the lower deep cervical nodes
  • A strip of the scalp above the auricle drains to the upper deep cervical and retro auricular nodes.
  • The retro auricular in turn drain to deep cervical.

NERVE SUPPLY:

  • Scalp supplied by ten nerves on each side.
  • Five nerves (4 sensory and one motor) enter scalp in front of the auricle.
  • Remaining five (4 sensory one motor) enter behind the auricle.          

IN FRONT OF AURICLE (SENSORY)

BEHIND THE AURICLE (SENSORY)

SUPRATROCHLEAR branch of the Frontal (Opthalmic div. of trigeminal nerve)

POSTERIOR DIVISION OF GREATER  AURICULAR (C2,C3) from cervical plexus

SUPRAORBITAL branch of Frontal

(Opthalmic division of trigeminal nerve)

LESSER OCCIPITAL (C2), from cervical plexus

ZYGOMATICOTEMPORAL, branch of zygomatic   nerve (Maxillary division of trigeminal nerve)

GREATER OCCIPITAL (C2, dorsal ramus)

AURICULOTEMPORAL branch of mandibular division of trigeminal nerve.

THIRD OCCIPITAL (C3, dorsal ramus)

(MOTOR)

(MOTOR)

TEMPORAL BRANCH OF FACIAL NERVE

POSTERIOR AURICULAR BRANCH OF FACIAL      NERVE

 CLINICAL ANATOMY:

  1. SEBACEOUS CYST- due to collection of sebum as a result of obstruction of sebaceous cyst, secondary infection may sets in.
  2. Scalp wounds bleed profusely-  because elastic fibres of underlying galea aponuerotica prevent initial vessel retraction, the wounds may be associated with significant blood loss which can result in clinical shock.
  3. Scalp flaps -used in craniofacial surgery for correction of congenital deformity,for release of craniosynostosis, treatment of craniofacial fractures and for repair of scalp defects after excision of skin tumors.
  4. Hemostasis in scalp wound is best achieved by pressure over wound.
  5. When suturing scalp lacerations, it is essential to control all bleeding points before repairing the scalp itself.
  6. It is necessary to tie off larger arterioles and veins and use bipolar diathermy to control smaller arterioles and veins.
  7. Repair of scalp require full thickness tension sutures because galea aponuerotica will otherwise gape as the occipital and frontal bellies contract.
  8. Lacerated wound appears as incised wound in scalp.
  9. Failure to control bleeding points  can result in significant hematomas, often subgaleal, leading to breakdown of the orginal wound and sometimes necessitating surgical drainage.
Don’t Forget to Solve all the previous Year Question asked on SCALP & SUPERFICIAL TEMPORAL REGIION

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