Anatomy of scalp

SCALP

Dr ARJUN SHENOYDEPT OF OMFS

CONTENTS

EXTENT LAYERSBLOODY SUPPLYVENOUS DRAINAGELYMPHATICSNERVE SUPPLYAPPLIED CLINICAL ANATOMYSCALP AVULSION INJURIES

EXTENT

The scalp extends from the top of the forehead in front to the superior nuchal line behind.

Laterally it projects down to the zygomatic arch and external acoustic meatus

CONSISTS OF FIVE LAYERS

SkinSubcutaneous tissueOccipitofrontalis (epicranius) and it’s

aponuerosisSubaponuerotic aereolar tissuepericranium

SKINThe skin is thick and hairy.

It is adherent to the epicranial aponuerosis through the dense superficial fascia.

SUPERFICIAL FASCIA

It is more fibrous and dense in the centre than at the periphery of the head.

Provides the proper medium for passage of vessels and nerves of the skin

EPICRANIAL APONUEROSIS

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.

LOOSE AEREOLAR TISSUE

Extends anteriorly into the eyelids.

Posteriorly to the highest and superior nuchal lines and on each side to the superior temporal lines.

PERICRANIUMLoosely 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 SUPPY

ARTERIAL SUPPLY

IN FRONT OF AURICLE-SupratrochlearSupraorbitalSuperficial temporal arteries

BEHIND THE AURICLEPosterior auricularOccipital arteries

VENOUS DRAINAGEEmissary veins connect the extracranial

veins with the intracranial venous sinuses to equalise the pressure.

The superficial temporal vein joins the maxillary vein to form retromandibular vein.

The supratrochlear and the supra orbital vein unite at the medial angle of eye to form angular vein

The posterior division of retromandibular vein unites with the posterior auricular vein to form external jugular vein

Frontal diploic- sphenoparietal sinusoccipital diploic- transverse sinus

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

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 BEHIND THE AURICLE

SUPRATROCHLEAR POSTERIOR DIVISION OF GREAT AURICULAR

SUPRAORBITAL LESSER OCCIPITAL

ZYGOMATICOTEMPORAL GREATER OCCIPITAL

AURICOTEMPORAL THIRD OCCIPITAL

MOTOR MOTOR

TEMPORAL BRANCH OF FACIAL

POSTERIOR AURICULAR BRANCH OF FACIAL

Supratrochlear nerve- smaller terminal branch of frontal nerve

Supplies the skin of the lower forehead near the midline

supraorbital- Divides into medial and lateral branches which

supply the skin of the scalp nearly as far back as the lambdoid suture

The medial perforates the muscle to reach the skinLateral pierces the epicranial aponuerosis

Zygomaticotemporal-Supplies skin of temple as it pierces the

deep layer of temporal fascia it sends a slender wig between the two layers towards the lateral angle of the eye.

Lesser occipital-supplies the scalp above and behind the ear . Branch of cervical plexus

Greater auricular-derived from anterior rami of second and third cervical spinal nerves.

Opthalmic nerve- skin over the forehead

CLINICAL ANATOMY

Since there are numerous sabaceous glands, the scalp is the commonest site for sabaceous cyst

Scalp lacerations 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.

It is very easy to raise a flap within the plane between the galea and the pericranium without compromising the blood or nerve supply of the scalp.

Similar flaps are seen in traumatic scalp avulsion,when hair is trapped in moving machinery

Scalp flaps can be 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

When suturing scalp lacerations, it is essential to control all bleeding points before repairing the scalp itself

Usually it is necessary to tie off larger arterioles and veins and use bipolar diathermy to control smaller arterioles and veins.

Repair of scalp require full thickness tension sutures because galea aponuerotica will otherwise gape as the occipital and frontal bellies contract.

Failure to control bleeding points as a separate step can result in significant hematomas,often subgaleal , leading to breakdown of the orginal wound and sometimes necessitating surgical drainage

LOCATING THE INCISION LINE AND PREPARATION

INCISION

ELEVATION OF CORONAL FLAP AND EXPOSURE OF ZYGOMATIC ARCH

SUBPERIOSTEAL EXPOSURE OF THE PERIORBITAL AREAS

HARVESTING CRANIAL BONE GRAFTS

SCALP AVULSION INJURIES

Dr. S. Raja Sabapathy,  Dr. Ravindra Bharathi, Dr. Hari Venkataramani, Dr. Deepak . K.L., Dr. Divakar Raju. K.             (Department of Plastic and Reconstructive Micro Surgery)BMMSRC

HANDLING THE AVULSED SCALP

The inner smooth surface of the avulsed scalp is first placed on a spherical vessel or container. This is done before clipping any hair. The long hair is then clipped and shaving commences from front to back and side to side, taking care not to shave the eyebrows. After the shaving is complete, the scalp is washed thoroughly in running tap water and only after all hair has been removed completely, the scalp is taken off the container. In this way, the scalp is well prepared and no hair is found on the inner side. This step hardly takes 10 min.

 All patients had acceptable recovery of sensation of forehead and scalp by 6–9 months after replantation. In two of our cases, the line of avulsion was along the level of medial canthus.Hair growth in all patients has been satisfactory and the cosmetic result excellent.

REFERENCES

Journal of Plastic, Reconstructive & Aesthetic Surgery

Volume 59, Issue 1, January 2006, Pages 2–10

GREYS ANATOMY