Download 01. scalp

DEFINITION
It is the soft tissue •
covering the Norma
Verticalis ( vault of the
skull) .
EXTENSION
It extends from the •
superciliary arches
anteriorly to the
external occipital
protuberance
posteriorly.
Laterally , it is •
continuous to the
zygomatic arch.
LAYERS
S
C
A
The scalp is formed of •
(Five) layers.
They can be defined •
by the word itself:
S –Skin. •
C –Connective tissue. •
A –Aponeurotic layer. •
LAYERS
L –Loose •
connective
tissue.
P - Periosteum •
L
P
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.
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.
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.
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.
OCCIPTOFRONTALIS
MUSCLE
It has a frontal •
belly anteriorly,
An occipital •
belly posteriorly,
and an
aponeurotic
tendon (galea
aponeurotica)
connecting the
two bellies.
FRONTAL BELLIY
It arises from the •
anterior part of the
aponeurosis.
It is inserted into •
the skin of the eye
brows.
FRONTAL BELLY
It elevates the •
eyebrows giving
the face a
surprised
looking and
produces
transverse
wrinkles of the
forehead.
OCCIPTAL BELLY
It arises from the •
highest nuchal lines
on the occipital
bone.
It passes superiorly •
to be
inserted into the •
aponeurosis.
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.
LOOSE AREOLAR
TISSUE
It occupies the •
subaponeurotic
space.
It contains few •
arteries and the
important
emissary veins.
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
SCALP INFECTIONS
It can spread •
through the
emissary veins to
the intracranial
venous sinuses to
cause Venous Sinus
thrombosis.
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.
SCALP INFECTIONS
Nor laterally •
because of
attachment of
the aponeurosis
to the temporal
fascia.
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.
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.
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.
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).
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.
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.
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.
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.
POSTERIOR TO THE EAR
3. Greater •
occipital
(posterior ramus
of C 2).
4. Third •
occipital
(posterior ramus
of C 3).
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.
OPTHALMIC ARTERY
1. Supratrochlear. •
2. Supraorbital. •
They accompany •
the corresponding
nerves to supply
the scalp as far as
the vertex.
EXTERNAL CAROTID
ARTERY
From the posterior •
aspect:
1. Posterior •
auricular:
It is the smallest •
branch.
It supplies the •
scalp posterior to
the ear.
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.
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.
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).
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.
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.
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.
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.
LYMPH DRAINAGE
Lymph vessels •
follow the arteries.
From the anterior •
part and forehead
drain into :
Submandibular
nodes.
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.
SCALP LACERATIONS
Wounds of the scalp •
bleed profusely
because of:
1. The abundant arterial •
anastomoses.
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.
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.