Download Scalp - M5zn

Dr. Ayat Eldomouky
Extention of
the scalp
Anterior:eyebrows.
Posterior:superior nuchal
line.
On each side:Superior
temporal line.
Layers of the scalp
S= skin
C= connective tissue
A= aponeurosis
L= loose areolar tissue
P= pericranium (periosteum)
The scalp is supplied by 5 arteries and drained by 5 veins .
1.
2.
3.
4.
5.
S
C
A
L
P
2- muscles of scalp
Occipito-frontalis muscle:
Origine:
1) Two frontal bellies: skin of forehead
2) Two occipital bellies: highest nucal line
Insertion:
Into the epicranial aponeurosis
Nerve supply: facial nerve
(all muscles of facial expression are innervated by facial nerve)
Action
Tense the aponeurosis
Raises the eyebrows and wrinkels the forehead
Nerve supply of the scalp
Infront of the
auricle
 5 nerves
 4 sensory (V)
 One motor (facial )
Behind the
auricle
 5 nerves
 4 sensory( cervical
nerves)
 One motor( facial )
Sensory Nerves
3rd occipital n.
G.Auricular n.
3-Nerves of scalp
4- arteries of scalp
Arteries : 5 on each side
a) Supratrochlear a. (from ophthalmic a. of the I.C.A.)
b) Supraorbital a. (from ophthalmic a. of the I.C.A.)
c) Superficial temporal a. (from E.C.A.)
d) Posterior auricular a. (from E.C.A.)
e) Occipital a. (from E.C.A.)
Notice :
1- The scalp has the richest cutaneous blood supply of the body.
2- The scalp is a site of anastomosis between I.C.A. and E.C.A.
3- The arteries come from the peripheries and anastomose freely in the scalp center
→ surgically scalp flaps are reflected downwards.
4- The scalp and face have no deep fascia.
Wound in the scalp is characterized by
1- Profuse bleeding.
2- Rapid healing.
3- Gapping (the aponeurosis is under tension).
4- Difficulty to ligate the bleeder due to the C.T. septa of the superficial fascia.
5- Blood in the loose areolar C.T. layer may reach to the face → black eye.
Superficial temporal A.
Supraorbital A.
Supratrochlear
Post.auricular A.
Occipital A.
Arteries of the Scalp
5-veins
of scalp
Veins : Correspond to the arteries:
1- Supratrochlear v .
+ 2- Supraorbital v. unite at the medial angle of the eye forming the
facial v.
3- Superficial temporal v. : Enters the parotid gland and unites with
the maxillary vein forming the retromandibular v
which divides into ant. and post. divisions. The 2 divisions leave the
lower end of the parotid gland.
4- Posterior auricular vein: Joins the post. division of
retromandibular vein to form the external jugular vein.
5- Occipital vein: Descends to join the suboccipital venous plexus.
(C) Emissary Veins
@ Definition: They are veins which connect the dural venous
sinuses inside the cranial cavity with the veins outside the
skull.
@ Characters :
1. They are valveless and so the blood
flows in them in both directions.
2. They pass through the foramina and fissures of the skull.
3. Some of them are constant while others may be present
or absent.
@ Function :
equalize the venous blood pressure between the
intracranial venous sinuses and the extracranial veins.
@ Clinical importance :
They can transmit infection from
outside the skull (eg. Dangerous area of face) to the
dural sinuses.
The dangerous area of the scalp is the subaponeurotic
space which is contains loose areolar tissue and
emissary veins so infection in this area can spread into
the intracranial tissue
Emissary Vs.
1- muscles of fascial expression
N.B: all muscles of facial expression are
innervated by facial nerve
a- orbicularies oculi
Orbicularies oculi muscle:
Origine & Insertion:
1) Orbital part: arises from the medial orbital margin and form a contineous
circles around the orbital margin
2) Palpebral part: arises from the the medial palpebral ligament to be
inserted into lateral palpebral raph
3) Lacrimal part: very small parts which surrounds the lacrimal sac
Nerve supply: facial nerve
(all muscles of facial expression are innervated by facial nerve)
Action
Firm closure of the eye the orbital part
And gentil closure of the eye by the palpebral part
B- orbicularies oris
It is formed mainly from thr fibers of the biccinator muscle and the anguli oris ,
Innervated by facial nerve
C-buccinator
Origine:
The upper fibers of the muscle arises from the maxilla and the
lower fibers arises from the mandible
The intermediate fibers arises from the pterygo-mandibular
ligament
Insertion:
The upper fibers inserted into the upper lip
The lower fibers inserted into the lower lip
The intermediate fibers decussate at the angle of the mouth
Nerve supply: facial nerve
(all muscles of facial expression are innervated by facial
nerve)
Action
Press the cheek against the gumes
Proper closure of the angle of the mouth
C- Risorius
“The grinning muscle”
Inserts horizontally into the angle of the mouth there by
retracting the angle
Superficial to buccinator